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  • 1.
    Aasa, Björn
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Orthopaedics. Norrlandsklinikens hälsocentral, Umeå, Sweden.
    Berglund, Lars
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Physiotherapy. Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Orthopaedics.
    Michaelson, Peter
    Luleå Tekniska Universitet, Institutionen för hälsovetenskap, Avdelningen för hälsa och rehabilitering, Fysioterapi.
    Aasa, Ulrika
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Physiotherapy.
    Individualized low-load motor control exercises and education versus a high-load lifting exercise and education to improve activity, pain intensity, and physical performance in patients with low back pain: a randomized controlled trial2015In: Journal of Orthopaedic and Sports Physical Therapy, ISSN 0190-6011, E-ISSN 1938-1344, Vol. 45, no 2, p. 77-85Article in journal (Refereed)
    Abstract [en]

    Study Design Randomized controlled trial. Background Low back pain is a common disorder. Patients with low back pain frequently have aberrant and pain-provocative movement patterns that often are addressed with motor control exercises. Objective To compare the effects of low-load motor control (LMC) exercise and those of a high-load lifting (HLL) exercise. Methods Seventy participants with recurrent low back pain, who were diagnosed with nociceptive mechanical pain as their dominating pain pattern, were randomized to either LMC or HLL exercise treatments. Participants were offered 12 treatment sessions over an 8-week period. All participants were also provided with education regarding pain mechanisms. Methods Participants were assessed prior to and following treatment. The primary outcome measures were activity (the Patient-Specific Functional Scale) and average pain intensity over the last 7 days (visual analog scale). The secondary outcome measure was a physical performance test battery that included 1 strength, 3 endurance, and 7 movement control tests for the lumbopelvic region. Results Both interventions resulted in significant within-group improvements in pain intensity, strength, and endurance. The LMC group showed significantly greater improvement on the Patient-Specific Functional Scale (4.2 points) compared with the HLL group (2.5 points) (P<.001). There were no significant between-group differences in pain intensity (P = .505), strength, and 1 of the 3 endurance tests. However, the LMC group showed an increase (from 2.9 to 5.9) on the movement control test subscale, whereas the HLL group showed no change (from 3.9 to 3.1) (P<.001). Conclusion An LMC intervention may result in superior outcomes in activity, movement control, and muscle endurance compared to an HLL intervention, but not in pain intensity, strength, or endurance.

  • 2.
    Aasa, Ulrika
    et al.
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Physiotherapy.
    Paulin, Johan
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    Madison, Guy
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    Correspondence between physical self-concept and participation in, and fitness change after, bi-weekly body conditioning classes in sedentary women2017In: Journal of Strength and Conditioning Research, ISSN 1064-8011, E-ISSN 1533-4287, Vol. 31, no 2, p. 451-461Article in journal (Refereed)
    Abstract [en]

    The aims of the study were (1) to investigate the effects of participation in low impact body conditioning classes on physical fitness in sedentary women at different ages and (2) to examine the correspondence between physical self-concept and participation in, and fitness change after, the participation. Ninety-two sedentary women (mean age 44.2 years) participated in 11-weeks of bi-weekly classes that included cardiovascular, strength, core, endurance and mobility exercises, all performed in synchrony with music. Cardiorespiratory fitness, maximal lifting strength, mobility and balance tests were performed pre- and post the exercise period and the short-form Physical Self-Description Questionnaire (PSDQ-S) was completed. Zero-order Spearman correlation analyses showed that women who rated the PSDQ-S dimension Sport competence higher participated in a larger number of sessions (rs=0.24, p=0.040). At post-tests, all participants had increased their balance, the participants aged 20-34 years had increased their lifting strength, and the participants aged 35-65 years had increased their cardiorespiratory fitness and mobility. Most PSDQ-S dimensions did not affect performance change, but the perception of being physically active was related to increased cardiovascular fitness. We conclude that women with a sedentary lifestyle who wish to increase their physical capacity benefit from music exercise and that inquiries about perceived sport competence and physical activity can improve recommendations made by strength and conditioning professionals.

  • 3.
    Albertsson, Sandra
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Sports Medicine.
    Juntunen, Martin
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Sports Medicine.
    Styrketräningsadaption: Aminosyrafördelning och intracellulär signalering2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Muscle mass regulation is responsive to a variety of stimuli, whereas amino acids and resistance exercise are two major regulators. Protein accretion occurs when the rate of protein synthesis exceeds the rate of protein degradation. It has long been recognized that both amino acid and resistance exercise effect protein synthesis and protein degradation, although the effect of varying distribution of amino acids remain unknown. The intracellular pathways by which protein synthesis are activated is complex. The purpose of this essay is to elucidate if there exist any scientific rationale to spread the amino acid intake over the day, with the purpose to maximize muscle protein accretion in response to resistance exercise. Furthermore , we intend to describe how amino acids and resistance exercise effect the molecular pathways that regulate protein synthesis, with the main focus on pathways that activate and are activated by mTOR.

    Studies that examine acute effects on protein synthesis or protein balance after resistance exercise and amino acid intake support the notion that there may be an advantage to spread the amino acid intake over the day, since the synthetic response to amino acids are transient. However, studies examining the effect of different meal frequencies on protein accretion and /or training results fail to support this notion. Both amino acids and resistance exercise seems to independently activate the intracellular pathways that regulate protein synthesis, with the effect being greatest when both are combined. The regulation also seems to be dependent on exercise intensity and volume, age of test subjects, contraction type and muscle fiber type. Furthermore, some researchers have found correlations between activation of these pathways and resistance exercise-induced muscle gain and strength gain.

  • 4.
    Alfredson, Hakan
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB). ISEH, UCLH, London, UK.
    Persistent pain in the Achilles midportion?: Consider the plantaris tendon as a possible culprit!2017In: British Journal of Sports Medicine, ISSN 0306-3674, E-ISSN 1473-0480, Vol. 51, no 10, p. 833-834Article, review/survey (Refereed)
  • 5.
    Alfredson, Håkan
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Sports Medicine.
    Can specific treatment prevent progressive tendon degeneration?2011In: British Journal of Sports Medicine, ISSN 0306-3674, E-ISSN 1473-0480, Vol. 45, no 4, p. 334-Article in journal (Refereed)
    Abstract [en]

    Background Tendon degeneration is generally believed to be irreversible.

    Objective To use ultrasound to study the Achilles midportion tendon structure and thickness before and after treatment of chronic painful tendinosis.

    Design Prospective study.

    Patients and interventions Middle aged patients on varying activity levels, having midportion chronic Achilles tendinosis, were followed with ultrasound examinations before and after treatment with eccentric training, sclerosing polidocanol injections and surgical scraping.

    Outcome measurements Tendon thickness and structure.

    Results 89 patients successfully treated (pain-free during tendon loading) with eccentric training (n=22), sclerosing polidocanol injections (n=38) and surgical scraping (n=29), had a significantly thinner Achilles midportion and a more normal tendon structure, after compared to before, treatment.

    Conclusion For the Achilles midportion, tendon degeneration might not be irreversible. The findings indicate a possible regeneration potential.

  • 6.
    Alfredson, Håkan
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Sports Medicine.
    Eccentric calf muscle training: the story2010In: Sportverletzung, Sportschaden, ISSN 0932-0555, E-ISSN 1439-1236, Vol. 24, no 4, p. 188-189Article in journal (Refereed)
  • 7.
    Alfredson, Håkan
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation. 2Institute of Sport, Exercise and Health, University College London Hospitals, London, UK.
    Low recurrence rate after mini surgery outside the tendon combined with short rehabilitation in patients with midportion Achilles tendinopathy2016In: Open Access Journal of Sports Medicine, ISSN 1179-1543, E-ISSN 1179-1543, Vol. 7, p. 51-54Article in journal (Refereed)
    Abstract [en]

    Background: There is a general opinion that a structured and specific rehabilitation is needed after treatment of midportion Achilles tendinopathy to minimize recurrence of the condition. There is sparse knowledge about the recurrence rates in large patient materials after specific treatments for midportion Achilles tendinopathy.

    Aim: This study aimed to investigate the recurrence rates in a large number of patients with chronic painful midportion Achilles tendinopathy that had been surgically treated with the ultrasound (US) and Doppler (DP)-guided mini-surgical scraping technique. Postoperatively, a relatively simple rehabilitation protocol, including a range of movement exercises and gradually increased walking and biking before allowing free activity, was used.

    Materials and methods: From a database, information about the recurrence rates after US + DP-guided mini-surgical scraping, performed by a single surgeon on 519 tendons with US + DP-verified chronic painful midportion Achilles tendinopathy, was obtained.

    Results: Recurrence of painful midportion Achilles tendinopathy was found in 26 of 519 (5%) operated tendons, 13 from women and 13 from men. In 13 tendons, a close by located plantaris tendon was extirpated during the reoperation.

    Conclusion: In this large material on patients treated with US + DP-guided mini-surgical scraping for midportion Achilles tendinopathy, there were few recurrences, although only a simple and nonspecific rehabilitation protocol was used.

  • 8.
    Alfredson, Håkan
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Sports Medicine.
    Midportion Achilles tendinosis and the plantaris tendon2011In: British Journal of Sports Medicine, ISSN 0306-3674, E-ISSN 1473-0480, Vol. 45, no 13, p. 1023-1025Article in journal (Refereed)
    Abstract [en]

    Objectives: When re-operating patients with midportion Achilles tendinosis, having had a poor effect of ultrasound (US) and Doppler-guided scraping, the author found the involvement of the plantaris tendon to be a likely reason for the poor result. The aim of this study was to investigate the occurrence of a plantaris tendon in close relation to the Achilles tendon in consecutive patients with midportion Achilles tendinosis undergoing treatment with US and Doppler-guided scraping.

    Material and methods: This study includes 73 consecutive tendons with chronic painful midportion Achilles tendinosis, where US+Doppler examination showed thickening, irregular tendon structure, hypo-echoic regions, and localised high blood flow outside and inside the ventral Achilles midportion. The tendons were treated with US+Doppler-guided scraping, via a medial incision. If there was a plantaris tendon located in close relation to the medial Achilles, it was extirpated.

    Results: An invaginated, or ‘close by located’, enlarged plantaris tendon was found in 58 of 73 (80%) tendons. Preliminary clinical results of the combined procedure, US + Doppler-guided surgical scraping and extirpation of the plantaris tendon, are very promising.

    Conclusions: A thickened plantaris tendon located in close relation to the medial Achilles seems common in patients with chronic painful midportion tendinosis. The role of the plantaris tendon in midportion Achilles tendinosis needs to be further evaluated and should be kept in mind when treating this condition.

  • 9.
    Alfredson, Håkan
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Sports medicine.
    Reply to the letter from Dr. Karsten Knobloch regarding our article "Sclerosing injections to treat midportion Achilles tendinosis: a randomized controlled study evaluating two different concentrations of polidocanol"2009In: Knee Surgery, Sports Traumatology, Arthroscopy, ISSN 0942-2056, E-ISSN 1433-7347, Vol. 17, no 1, p. 113-114Article in journal (Other academic)
  • 10.
    Alfredson, Håkan
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Sports Medicine. National Institute for Working Life, University of Umeå , 901 87, Umeå, Sweden .
    Strategies in treatment of tendon overuse injury. The chronic painful tendon.2006In: European Journal of Sport Science, ISSN 1746-1391, E-ISSN 1536-7290, Vol. 6, no 2, p. 81-85Article in journal (Refereed)
    Abstract [en]

    The etiology and pathogenesis to chronic tendon pain is unknown, and treatment is known to be difficult. Treatment is often based on opinions and not findings in scientific studies. Recent research, using the intra-tendinous microdialysis technique, has shown that in chronic painful Achilles-, patellar-, and extensor carpi radialis brevis (ECRB) tendons, there were no signs (normal Prostaglandin-2 levels) of a so-called chemical inflammation. Furthermore, in biopsies from chronic painful Achilles tendons, pro-inflammatory cytokines were not up-regulated, again showing the absence of an intra-tendinous inflammation. Consequently, if the purpose is to treat a chemical inflammation, there is no science backing up for treatment of theses conditions with anti-inflammatory agents (NSAIDs, corticosteroidal injections). Interestingly, Substance-P (SP) and Calcitonin Gene Regulated Peptide (CGRP) nerves have been demonstrated in close relation to vessels in biopsies from these chronic painful tendons, indicating the existence of a possible so-called neurogenic inflammation. Using ultrasonography (US) + color Doppler (CD), and immunhistochemical analyses of biopsies, a vasculo/neural (SP- and CGRP-nerves) ingrowth in the chronic painful tendinosis tendon, but not in the pain-free normal tendon, has recently been found. A specially designed treatment, using US- and CD-guided injections of the sclerosing agent Polidocanol, targeting the neovessels outside the tendon, has in pilot studies on chronic painful Achilles-, and patellar tendons been shown to cure the tendon pain in the majority of patients. A recent randomized double-blind study, verified the importance of injecting the sclerosing substance Polidocanol.

  • 11.
    Alfredson, Håkan
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Sports Medicine.
    Ultrasound and Doppler-guided mini-surgery to treat midportion Achilles tendinosis: results of a large material and a randomised study comparing two scraping techniques.2011In: British Journal of Sports Medicine, ISSN 0306-3674, E-ISSN 1473-0480, Vol. 45, no 5, p. 407-410Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Treatment based on ultrasound (US) and colour Doppler (CD) findings in midportion Achilles tendinosis has shown promising results. In a randomised study on a small patient material, similar short-term clinical results were demonstrated with surgery outside the tendon and sclerosing polidocanol injections, but surgical treatment led to a faster return to activity.

    OBJECTIVE: To evaluate the clinical results of US and CD-guided mini-surgery (scraping) outside the ventral tendon in a larger patient material and, in a randomised study, compare two different techniques for surgical scraping.

    MATERIAL AND METHODS: 103 patients (66 men, 37 women), mean age 43 years (range 24-77), with midportion tendinosis in 125 Achilles tendons were included. Patients from a large group (88 tendons), and a randomised study (37 tendons), were in local anaesthesia treated with a US and CD-guided new surgical approach outside the ventral tendon. All patients in the large group, and one arm of the randomised study, were treated open with a scalpel, while the other arm of the randomised study were treated percutaneously. Pain during Achilles tendon loading activity (Visual Analogue Scale (VAS)), and satisfaction with treatment, were evaluated.

    RESULTS: Before surgery, the mean VAS was 73. After surgery (follow-up mean 18 months, range 6-33), the mean VAS was 3 in 111 tendons (89%) from satisfied patients back in full Achilles tendon loading activity. In the randomised study, there were no significant differences in the results between open treatment with a scalpel and percutaneous treatment with a needle.

    CONCLUSIONS: US and CD-guided scraping show good short-term results in midportion Achilles tendinosis.

  • 12.
    Alfredson, Håkan
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Sports Medicine.
    Where to now with Achilles tendon treatment?2011In: British Journal of Sports Medicine, ISSN 0306-3674, E-ISSN 1473-0480, Vol. 45, no 5, p. 386-386Article in journal (Refereed)
  • 13.
    Alfredson, Håkan
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Sports Medicine.
    Masci, Lorenzo
    Öhberg, Lars
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Partial midportion Achilles tendon ruptures: new sonographic findings helpful for diagnosis.2011In: British Journal of Sports Medicine, ISSN 0306-3674, E-ISSN 1473-0480, Vol. 45, no 5, p. 429-432Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Partial Achilles tendon ruptures are not always easy to diagnose. A history including a sudden onset of pain, and/or relative weakness in plantar flexion force, are indicators. The most loaded side of the Achilles tendon is the dorsal side (skin side). OBJECTIVE: To evaluate the ultrasound (US) and Doppler (CD) findings in patients with a suspected partial rupture in the Achilles tendon. Material and METHODS: Seventeen patients (16 men and 1 woman) with a mean age of 36 years (range 23-71) were examined clinically and by US+CD because of midportion Achilles tendon pain. There was an acute onset in 14/17 patients, and all had painful weakness during tendon loading activity. RESULTS: In all patients the US examination showed a partial Achilles tendon rupture, presented as a disrupted dorsal (skin side) tendon line and an irregular tendon structure mainly located in the dorsal and mid-tendon. The size of the rupture varied from 1/3 to 2/3 of the tendon thickness. In the dorsal part of the tendon, corresponding to the region with disrupted tendon line and irregular structure, CD examination showed high blood flow-most often of a longitudinal character. Six of the patients were surgically treated, and macroscopical examination verified the ultrasound findings, showing disruption on the dorsal side, and a partial rupture in the dorsal and mid- tendon. CONCLUSIONS: Ultrasound and Doppler examination can be helpful tools to diagnose partial midportion Achilles tendon ruptures. The characteristic findings of a disrupted dorsal tendon line, and high blood flow in the structurally abnormal dorsal tendon, indicate a partial rupture.

  • 14.
    Alfredson, Håkan
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Sports Medicine.
    Spang, Christoph
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Anatomy.
    Forsgren, Sture
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Anatomy.
    Unilateral surgical treatment for patients with midportion Achilles tendinopathy may result in bilateral recovery2014In: British Journal of Sports Medicine, ISSN 0306-3674, E-ISSN 1473-0480, Vol. 48, no 19, p. 1421-1424Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Bilateral midportion Achilles tendinopathy/tendinosis is not unusual, and treatment of both sides is often carried out. Experiments in animals suggest of the potential involvement of central neuronal mechanisms in Achilles tendinosis. OBJECTIVES: To evaluate the outcome of surgery for Achilles tendinopathy. METHODS: This observational study included 13 patients (7 men and 6 women, mean age 53 years) with a long duration (6-120 months) of chronic painful bilateral midportion Achilles tendinopathy. The most painful side at the time for investigation was selected to be operated on first. Treatment was ultrasound-guided and Doppler-guided scraping procedure outside the ventral part of the tendon under local anaesthetic. The patients started walking on the first day after surgery. Follow-ups were conducted and the primary outcome was pain by visual analogue scale. In an additional part of the study, specimens from Achilles and plantaris tendons in three patients with bilateral Achilles tendinosis were examined. RESULTS: Short-term follow-ups showed postoperative improvement on the non-operated side as well as the operated side in 11 of 13 patients. Final follow-up after 37 (mean) months showed significant pain relief and patient satisfaction on both sides for these 11 patients. In 2 of 13 patients operation on the other, initially non-operated side, was instituted due to persisting pain. Morphologically, it was found that there were similar morphological effects, and immunohistochemical patterns of enzyme involved in signal substance production, bilaterally. CONCLUSION: Unilateral treatment with a scraping operation can have benefits contralaterally; the clinical implication is that unilateral surgery may be a logical first treatment in cases of bilateral Achilles tendinopathy.

  • 15.
    Alfredson, Håkan
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Sports Medicine.
    Tol, Johannes
    Sports Medicine Physician Aspetar Qatar Orthopaedic and Sports Medicine Hosptial Doha, Qatar.
    de-Vos, Robert-Jan
    Erasmus Medical Centre and The Hague Medical Centre Rotterdam, The Netherlands.
    Chronic pain in the Achilles tendon2013In: Aspetar Sports Medicine Journal, Vol. 2, no 1, p. 18-22Article in journal (Other academic)
  • 16.
    Alm, Petter
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Sports Medicine.
    Evaluation of Physiological Characters in Mixed Martial Arts Athletes2012Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Abstract

    Introduction: MMA is a relatively new sport and is a mixture of many different martial arts. Currently, studies on the physiological characters of MMA athletes are very limited. The present study is mainly interested in evaluation of MMA athletes with respect to the aerobic and anaerobic capacity.

    Method and materials: 5 male pro MMA athletes were recruited for the study. VO2max and anaerobic threshold measured with different methods were evaluated on treadmill and arm cycle. Muscle strength and power was evaluated through measurement of squat jump, counter movement jump, counter movement jump with arm swing, maximum clean, maximum deadlift and maximum reps of vertical sit-ups. Body composition including bone mineral density, muscle mass and fat mass were also measured.  All the above measurements were performed twice with one year in between. Personal competition records expressed as percentage of win in total competition during the past year or the whole years before each test occasion were also calculated. 

    Result: except for a lower relative VO2max (both on treadmill and arm cycle) and [La] 0min after treadmill test, none of the measurements on absolute VO2max, anaerobic thresholdor body composition showed significant difference in values between the two test occasions. A tendency of decrease in muscle strength/power was observed in the second occasion, where the lower squat jump (cm) and counter movement jump with arm swing (cm/kg) were significant.

    Conclusion: the MMA athletes have reached their physiological capacity needed for the sport or did not prioritized their strength and conditioning training high enough to improve them further.

  • 17.
    Alm, Petter
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Sports Medicine.
    Yu, Ji-Guo
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Sports Medicine.
    Physiological characters in mixed martial arts2013In: American Journal of Sports Science, ISSN 2330-8540, Vol. 1, no 2, p. 12-17Article in journal (Refereed)
    Abstract [en]

    Mixed martial arts (MMA) is a relatively new sport and is a mixture of many different martial arts. Currently, study on the physiological characters in the sport is very limited. The present study evaluated the physiological characters in 5 active male MMA athletes at two occasions with one year between. Aerobic- and anaerobic capacity were estimated through measurement of VO2max and anaerobic threshold using both treadmill running and arm cycling. Muscle strength was evaluated through series measurements. Body composition and personal competition records were also examined. The subjects presented above average aerobic capacity, but rather high anaerobic capacity and threshold levels compared with other similar sports. No significant difference in VO2max, anaerobic threshold or body composition was observed between the two test occasions, despite a decreased tendency in muscle strength/power in the second test compared to the first. The results were interpreted to indicate either the MMA athletes had reached the physiological requirements for MMA or the one year physical training was inefficient in further improving the parameters.                                              

  • 18.
    Almgren, Simon
    et al.
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Sports medicine.
    Danielsson, Andreas
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Sports medicine.
    Påverkan av Muskeltrötthet på Motorisk Kontroll hos Kvinnliga Innebandyspelare2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Non-contact injuries are a big part of overall injuries in floorball. Deficits in motor control due to muscle fatigue may be a factor that causes non-contact injuries. We analyzed movement changes with The Functional Movement ScreenTM (FMS) with and without muscle fatigue on women floorball players. Method: A pilot study with a cross-sectional structure. FMS test was used to measure changes in movements and to reach fatigue a 5-10 min running ramp protocol on treadmill was used. The borg RPE-scale was used to measure perceived exhaustion. Participants: Seven female floorball players playing in teams at the highest two leagues in Sweden. The participants age was 19.7 (±SD 3,2) years, length 166.4 cm (±SD 7,2) and weight 63.1 kg (±SD 4,5). Results: Through observations of the participants we noted a different movement pattern while obtaining muscle fatigue. The results of FMS total score shows no significant difference (p=0,504) before and after the VO2max running test. The FMS results from exercises that includes the lower extremities (deep squat, hurdle step, in-line lunge and straight leg raise) does not either confirm a significant difference (p=0,132). Discussion: Our subjective analyze of the movements confirms a different movement strategy with and without muscle fatigue. The non-parametric statistical analyze does not confirm this change in movements as significant. The Functional Movement Screen might not be a good tool to measure changes in movement because the movement change has to be in a specific criteria to get a lower point. Even though we saw a different movement strategy after the ramp running test, the deficit in movements was not in the specific criteria that was necessary to get a lower point. Conclusion: Through the test results and our observations we conclude that movement pattern change after an exercise that causes fatigue, does not completely show how much the movement patterns changes and what the consequences are. More research has to be done in this area to confirm such results.

  • 19.
    Alvehus, Malin
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Boman, Niklas
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Sports Medicine.
    Söderlund, Karin
    Svensson, Michael B.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Sports Medicine.
    Buren, Jonas
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Metabolic adaptations in skeletal muscle, adipose tissue, and whole-body oxidative capacity in response to resistance training2014In: European Journal of Applied Physiology, ISSN 1439-6319, E-ISSN 1439-6327, Vol. 114, no 7, p. 1463-1471Article in journal (Refereed)
    Abstract [en]

    The effects of resistance training on mitochondrial biogenesis and oxidative capacity in skeletal muscle are not fully characterized, and even less is known about alterations in adipose tissue. We aimed to investigate adaptations in oxidative metabolism in skeletal muscle and adipose tissue after 8 weeks of heavy resistance training in apparently healthy young men. Expression of genes linked to oxidative metabolism in the skeletal muscle and adipose tissue was assessed before and after the training program. Body composition, peak oxygen uptake (VO2 peak), fat oxidation, activity of mitochondrial enzyme in muscle, and serum adiponectin levels were also determined before and after resistance training. In muscle, the expression of the genes AdipoR1 and COX4 increased after resistance training (9 and 13 %, respectively), whereas the expression levels of the genes PGC-1 alpha, SIRT1, TFAM, CPT1b, and FNDC5 did not change. In adipose tissue, the expression of the genes SIRT1 and CPT1b decreased after training (20 and 23 %, respectively). There was an increase in lean mass (from 59.7 +/- A 6.1 to 61.9 +/- A 6.2 kg), VO2 peak (from 49.7 +/- A 5.5 to 56.3 +/- A 5.0 ml/kg/min), and fat oxidation (from 6.8 +/- A 2.1 to 9.1 +/- A 2.7 mg/kg fat-free mass/min) after training, whereas serum adiponectin levels decreased significantly and enzyme activity of citrate synthase and 3-hydroxyacyl-CoA dehydrogenase did not change. Despite significant increases in VO2 peak, fat oxidation, and lean mass following resistance training, the total effect on gene expression and enzyme activity linked to oxidative metabolism was moderate.

  • 20. Aman, Malin
    et al.
    Forssblad, Magnus
    Henriksson-Larsén, Karin
    Insurance claims data: a possible solution for a national sports injury surveillance system? An evaluation of data information against ASIDD and consensus statements on sports injury surveillance2014In: BMJ Open, ISSN 2044-6055, E-ISSN 2044-6055, Vol. 4, no 6, article id e005056Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Before preventive actions can be suggested for sports injuries at the national level, a solid surveillance system is required in order to study their epidemiology, risk factors and mechanisms. There are guidelines for sports injury data collection and classifications in the literature for that purpose. In Sweden, 90% of all athletes (57/70 sports federations) are insured with the same insurance company and data from their database could be a foundation for studies on acute sports injuries at the national level.

    OBJECTIVE: To evaluate the usefulness of sports injury insurance claims data in sports injury surveillance at the national level.

    METHOD: A database with 27 947 injuries was exported to an Excel file. Access to the corresponding text files was also obtained. Data were reviewed on available information, missing information and dropouts. Comparison with ASIDD (Australian Sports Injury Data Dictionary) and existing consensus statements in the literature (football (soccer), rugby union, tennis, cricket and thoroughbred horse racing) was performed in a structured manner.

    RESULT: Comparison with ASIDD showed that 93% of the suggested data items were present in the database to at least some extent. Compliance with the consensus statements was generally high (13/18). Almost all claims (83%) contained text information concerning the injury.

    CONCLUSIONS: Relatively high-quality sports injury data can be obtained from a specific insurance company at the national level in Sweden. The database has the potential to be a solid base for research on acute sports injuries in different sports at the national level.

  • 21.
    Anckarman, Erika
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Sports medicine.
    Den framgångsrika personliga tränaren: En kvalitativ studie om klienters upplevelse av vilka egenskaper och faktorer som är viktiga för personliga tränare2016Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Background: During the last years the fitness industry has expanded fast. Today PT is offered at almost every health club. Training with a PT have positive physical effects but it has also shown an influence on behaviour associated with training. A good relation between client and coach is needed for a positive outcome of the training.

    Purpose: The aim of the study was to investigate what the clients that are training or has trained with at personal trainer during the last year consider as important factors and personal qualities related to personal trainers.

    Design and method: A qualitative descriptive design was used. Data collection was done by semi-structured interviews. Data was analysed with qualitative content analysis.

    Results: The analyses resulted in 3 themes, 6 categories and 17 sub categories. The themes and categories were: To appear as competent: Appearance and displayed experience ,Give a feeling of a broad knowledge.

    Coaching style: To be present here and now, To personalize Pedagogical strategies: Tools to reach results, To create a secure feeling,

    Conclusion: Background information of the PT should always be available at the health club or on the website. The client should have the opportunity to choose a PT based on their personal requests. This may result in good preconditions for a strong and effective working alliance. Reserach in this area are limited therefor further studies are needed. 

  • 22.
    Anderback, Nanny-Maja
    et al.
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Sports medicine.
    Öling, Kajsa
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Sports medicine.
    Kan fysisk aktivitet under graviditeten reducera graviditetsrelaterade besvär?2017Independent thesis Basic level (degree of Bachelor), 180 HE creditsStudent thesis
    Abstract [en]

    Background: Many women are pregnant for one or more periods of their lives. During this time, studies have shown that women tend to become physically inactive. With a pregnancy, there is also an increased risk of other diseases and disorders such as pregnancy diabetes and obesity. Studies have shown that physical activity can prevent some of these disorders. Traditionally, the general opinion on physical activity during pregnancy has been that it could be dangerous for both the pregnant woman and the fetus. Today, there is a more liberal view of physical activity during pregnancy, but research is still inadequate.Aim: Our purpose with this literature study is to examine the effects of physical activity during pregnancy in pregnancy-related disorders, and look into the current recommendations on physical activity during pregnancy.Results: Our study has seen positive effects of physical activity during pregnancy especially in pregnancy-related disorders such as lumbar pain, pelvic floor dysfunction, fatigue, gestational diabetes and weight gain, as well as some positive trends in preeclampsia, edema and pelvic girdle pain. The research on nausea and rectus diastasis is too inadequate to draw any conclusions about possible effects.Conclusion: More RCT studies on pregnancy-related disorders are needed to reach consensus about what type of physical activity, duration, intensity and frequency during pregnancy that are beneficial for these disorders. From this knowledge we can then work out more specific recommendations.

  • 23.
    Andersson, Annie
    et al.
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Sports medicine.
    Björkén, Rebecca
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Sports medicine.
    Kan fysisk aktivitet och kost ha en positiv inverkan på fysiska och psykiska subkliniska menstruella besvär?2018Independent thesis Basic level (degree of Bachelor), 180 HE creditsStudent thesis
    Abstract [en]

    Background: Many women experience physical and psychological symptoms during their menstrual cycle. Research is scarce about how to ease subclinical menstrual disorders like dysmenorrhea, menorrhagia, premenstrual syndrome, premenstrual dysphoric syndrome, oligomenorrhea and amenorrhea without using medicines. Physical activity and diet is proved to have positive effects on several diseases and we therefore wanted to see if positive effects also could be seen on subclinical menstrual disorders.

    Aim: The aim of this study was to investigate if physical activity and diet could reduce physical and psychological subclinical menstrual disorders and lead to a better wellbeing.

    Method: Searching for subclinical menstrual disorders in relation to physical activity and diet in fertile, active and inactive women without the use of hormonal contraceptives was done using Pubmed.

    Results: The study has shown that physical activity and diet could reduce some of the problems associated with subclinical menstrual disorders. Premenstrual syndrome (PMS) could be eased through calm, meditative activities. Positive effects could be seen when eating more often but smaller meals containing complex carbohydrates and by taking additional vitamins and minerals. Yoga has been proved to reduce menstrual pain and there’s also an indication that physical activity could improve the regularity of the menstrual cycle. Adequate energy intake is needed to avoid oligomenorrhea and amenorrhea. No clear recommendations were found for the remaining subclinical menstrual disorders.

    Conclusion: The study has shown that physical activity and diet have positive effects on some subclinical menstrual disorders. Symptoms of PMS could be eased by calm, meditative activities. Yoga and physical activity have been shown to reduce dysmenorrhea. Adequate energy intake is essential to avoid oligomenorrhea and amenorrhea. Further research is needed to give general recommendations.

  • 24.
    Andersson, Gustav
    et al.
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Anatomy.
    Backman, Ludvig
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Anatomy.
    Scott, Alexander
    Department of Physical Therapy, University of British Columbia, Vancouver, British Columbia, Canada; Centre for Hip Health and Mobility, Vancouver Coastal Health and Research Institute, Vancouver, British Columbia, Canada.
    Lorentzon, Ronny
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Sports Medicine.
    Forsgren, Sture
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Anatomy.
    Danielson, Patrik
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Anatomy.
    Substance P accelerates hypercellularity and angiogenesis in tendon tissue and enhances paratendinitis in response to Achilles tendon overuse in a tendinopathy model2011In: British Journal of Sports Medicine, ISSN 0306-3674, E-ISSN 1473-0480, Vol. 45, no 13, p. 1017-1022Article in journal (Refereed)
    Abstract [en]

    Background Tenocytes produce substance P (SP) and its receptor (neurokinin-1 receptor (NK-1R) is expressed throughout the tendon tissue, expecially in patients with tendinopathy and tissue changes (tendinosis) including hypercellularity and vascular proliferation. Considering the known effects of SP, one might ask whether SP contributes to these canges.

    Objectives To test whether development of tendinosislike changes (hypercellularity and angiogenesis) is accelerated during a 1-week course of ecercise with local administration of SP in an establish Achilles tendinopathy model.

    Methods Rabbits were subjected to a protocol of Achilles tendon overuse for 1 week, in conjunction with SP injections in the paratenon. Exercised control animals received NaCl injections or no injections, and unexercised, uninjected controls were also used. Tenocyte number and vascular density, as well as paratendinous inflammation, were evaluated. Immunohistochemistry and in sity hybridisation to detect NK-1R were conducted.

    Results There was a significant increase in tenocyte number in the SP-injected and NaCl-injected groups compared with both unexercised and exercised, uninjected controls. Tendon blood vessels increased in number in the SP-injected group compared with unexercised controls, a finding not seen in NaCl-injected controls or in uninjected, exercised animals. Paratendinous inflammation was more pronounced in the SP-injected group than in the NaCl controls. NK-1R was detected in blood vessel walls, nerves, inflammatory cells and tenocytes.

    Conclusions SP accelerated the development of tendinosis-like changes in the rabbit. Achilles tendon, which supports theories of a potential role of SP in tendinosis development; a fact of clinical interest since SP effects can be effectively blocked. The angiogenic response to SP injections seems related to parateninitis.

  • 25.
    Andersson, Hannes
    et al.
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Sports medicine.
    Gröntvedt, John
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Sports medicine.
    Effekten av 8-veckors medicinbollsträning på smashhastighet hos badmintonspelare2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 26.
    Andersson, Linda
    et al.
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Sports medicine.
    Andersson, Ida
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Sports medicine.
    Samband mellan överkroppsstyrka och prestation i skidspåret hos svenska längdskidåkande juniorer.2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Previous research has identified strength as a key factor for performance in cross-country skiing. The purpose of the present study was to investigate the relationship between upper body strength and performance in swedish junior cross-country skiers. 33 swedish young men and 23 young women age 17,3 ± 1,0 years volunteered to participate in specific tests during a summer training camp were they completed a test battery consisting of bench press and bench pull. The strength variables obtained were correlated with FIS-points (International Ski Federation´s ranking points for distance and sprint performance) used as the performance indicator. Correlations were performed by Spearman´s rank correlation coefficient for all variables. The results showed that FIS-points for sprint correlated significantly with both bench press and bench pull. No significant correlation was found between FIS-points for distance and bench pull. These results may predict performance for cross-country skiers and indicate a justification for increased proportion of strength training. 

  • 27.
    Andersson, Terese
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Sports medicine.
    Menstruationscykelns och p-pillers påverkan på den fysiska prestationsförmågan2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Effects of Menstrual Cycle and Oral Contraceptives on Sport Performance

    During the menstrual cycle, there is a variation of the female steriod hormones estrogen and progestogen. These hormones has mainly reproduktive functions, but do also affect other physiological systems, which may have an influence on athletic performance. The use of oral contraceptives among female athletes matches the use among the general population. There is a concern among female athletes and there coaches weather oral contraceptives can affect the performance. The purpose of this litterature review is to determine the effect of the menstrual cycle and the use of oral contraceptives on athletic performance. Most studies indicates that neither the aerobic performance or VO₂max changes during the mestrual cycle, but an increase in ventilation during the lutheal phase has been observed. In the lutheal phase, the body temperature is elevated, which can affect the performance negatively during physical activity in hot and humid conditions. Studies evaluating the anaerobic performance shows varied results, which can be explained by few study participants, different study designs and varying definitions of menstrual cycle phase. Some studies that have examined the strength variation have not seen any difference, and others have seen an advantage during the follicular phase, when it also seems to be beneficial to train more strength training to optimize training adaptation. The use of oral contraceptives can affect the body composition of female athletes. Fat mass and BMD can increase, and is seen mainly in athleteswith mestrual dysfunctions. This can be benificial for their health and decrease the risk of injury, but may decrease performace level. The effect of oral contraceptive administration on aerobic capacity, anaerobic capacity and strength are unclear and the research has come up with varying results. Future studies should investigate oneoral contraceptive pill formulation at a time, andalso compare different formulations, to determineif that affect performance in different ways.

    Key words: menstruation, oral contraceptives, female athlete, performance, hormones

  • 28.
    Arumugam, Ashokan
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Physiotherapy.
    Clinical versus radiological findings: A paradox in diagnosing minor hamstring injuries2018In: International Journal of Osteopathic Medicine, ISSN 1746-0689, E-ISSN 1878-0164, Vol. 27, p. 52-56Article in journal (Refereed)
    Abstract [en]

    Hamstring injuries occur commonly in athletes participating in sports that require sprinting/high velocity running, kicking a ball or agility. In the first instance, clinical assessment and management play a pivotal role in managing these injuries. Radiological investigations such as ultrasonography (US) and magnetic resonance imaging (MRI) are also recommended to confirm one or more parameters related to hamstring injury (the location, length, cross-sectional area, volume, edema, hemorrhage, etc.) and predicting return-to-play. However, hamstring injuries that are minor in nature, diagnosed clinically, may not be discernible on conventional US or MRI in some cases. Certain reasons for these paradoxical (clinical vs. radiological) findings may include pain referral to the posterior thigh from lumbosacral dysfunction or sciatic nerve pathoneurodynamics. Conversely, minor hamstring injuries might remain indiscernible within the threshold of conventional MRI sensitivity. To date, there is neither clear consensus on a standardized criteria nor strong evidence for using MRI to prognosticate return-to-play following hamstring injuries. This paper briefly discusses the controversy between contradicting clinical and radiological findings encountered by clinicians in the diagnosis of minor hamstring injuries. If posterior thigh pain appears with clinical signs and symptoms of a minor hamstring injury without pain referral from neighboring structures, but presents with negative findings on US or MRI, the diagnosis remains a challenge. However, such conditions are pragmatically treated as (nonstructural) hamstring injuries unless certain differential diagnoses can be established. 

  • 29.
    Asplund, Jeanette
    et al.
    Umeå University, Faculty of Social Sciences, Education.
    Svensson, Anna
    Umeå University, Faculty of Social Sciences, Education.
    Lär man sig något av idrottsundervisningen?: En studie om gymnasieelevers lärande i Idrott och hälsa A2006Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of this essay was to study what students at the upper secondary levels thought that they learned in physical education and if there were differences between girls and boys learning. The purpose was also to study different factors that could affect the learning and to show how curriculum and prior research relate to the students learning. In this essay we used the three aspects of health that are mentioned in the description of physical education: the physical, the social and the psychic. The study was based on a quantitative research where 165 students answered questionnaires about their learning. Our research showed that the students did not get the knowledge that the A-course in physical education should provide and that the goals for the course were not accomplished. From a gender perspective the boys learned more in comparison to the girls in several areas. The study also showed that the students that were physically active and who thought that physical education was fun were the ones who learned the most from the education. The students learning were also affected by different learning styles and by the teachers and their ways to plan their lessons.

  • 30.
    Awad, Amar
    et al.
    Umeå University, Faculty of Medicine, Umeå Centre for Functional Brain Imaging (UFBI). Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Physiology.
    Levi, Richard
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Rehabilitation Medicine.
    Lindgren, Lenita
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Physiology. Umeå University, Faculty of Medicine, Umeå Centre for Functional Brain Imaging (UFBI).
    Hultling, Claes
    Department of Neurobiology, Care Sciences and Society (Neurorehabilitation), Karolinska Institute, Stockholm, Sweden.
    Westling, Göran
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Physiology.
    Nyberg, Lars
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Physiology. Umeå University, Faculty of Medicine, Umeå Centre for Functional Brain Imaging (UFBI). Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Eriksson, Johan
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Physiology. Umeå University, Faculty of Medicine, Umeå Centre for Functional Brain Imaging (UFBI).
    Preserved somatosensory conduction in a patient with complete cervical spinal cord injury2015In: Journal of Rehabilitation Medicine, ISSN 1650-1977, E-ISSN 1651-2081, Vol. 47, no 5, p. 426-431Article in journal (Refereed)
    Abstract [en]

    Objective: Neurophysiological investigation has shown that patients with clinically complete spinal cord injury can have residual motor sparing ("motor discomplete"). In the current study somatosensory conduction was assessed in a patient with clinically complete spinal cord injury and a novel ethodology for assessing such preservation is described, in this case indicating "sensory discomplete" spinal cord injury. Methods: Blood oxygenation level-dependent functional magnetic resonance imaging (BOLD fMRI) was used to examine the somatosensory system in a healthy subject and in a subject with a clinically complete cervical spinal cord injury, by applying tactile stimulation above and below the level of spinal cord injury, with and without visual feedback. Results: In the participant with spinal cord injury, somatosensory stimulation below the neurological level of the lesion gave rise to BOLD signal changes in the corresponding areas of the somatosensory cortex. Visual feedback of the stimulation strongly modulated the somatosensory BOLD signal, implying that cortico-cortical rather than spino-cortical connections can drive activity in the somatosensory cortex. Critically, BOLD signal change was also evident when the visual feedback of the stimulation was removed, thus demonstrating sensory discomplete spinal cord injury. Conclusion: Given the existence of sensory discomplete spinal cord injury, preserved but hitherto undetected somatosensory conduction might contribute to the unexplained variability related to, for example, the propensity to develop decubitus ulcers and neuropathic pain among patients with clinically complete spinal cord injury.

  • 31.
    Backman, Ludvig
    et al.
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Anatomy. Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Sports Medicine.
    Andersson, Gustav
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Anatomy.
    Wennstig, Gabriel
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Anatomy.
    Forsgren, Sture
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Anatomy.
    Danielson, Patrik
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Anatomy.
    Endogenous substance P production in the Achilles tendon increases with loading in an in vivo model of tendinopathy: peptidergic elevation preceding tendinosis-like tissue changes2011In: Journal of Musculoskeletal and Neuronal Interactions - JMNI, ISSN 1108-7161, Vol. 11, no 2, p. 133-140Article in journal (Refereed)
    Abstract [en]

    Objectives: To quantify the intratendinous levels of substance P (SP) at different stages of overload in an established modelfor Achilles tendinopathy (rabbit). Also, to study the distribution of the SP-receptor, the NK-1R, and the source of SP, in thetendon. 

    Methods: Animals were subjected to the overuse protocol for 1, 3 or 6 weeks. One additional group served as unexercisedcontrols. Immunoassay (EIA), immunohistochemistry (IHC), and in situ hybridisation (ISH) were performed.

    Results: EIA revealedincreased SP-levels in the Achilles tendon of the exercised limb in all the experimental groups as compared to in thecontrols (statistically significant; p=0.01). A similar trend in the unexercised Achilles tendon was observed but was not statisticallysignificant (p=0.14). IHC and in ISH illustrated reactions of both SP and NK-1R mainly in blood vessel walls, but the receptorwas also found on tenocytes.

    Conclusions: Achilles tendon SP-levels are elevated already after 1 week of loading. This showsthat increased SP-production precedes tendinosis, as tendinosis-like changes occur only after a minimum of 3 weeks of exercise,as shown in a recent study using this model. We propose that central neuronal mechanism may be involved as similar trends wereobserved in the contralateral Achilles tendon.

  • 32.
    Backman, Ludvig J
    et al.
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Anatomy.
    Andersson, Gustav
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Anatomy.
    Fong, Gloria
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Anatomy. Department of Physical Therapy, University of British Columbia and Centre for Hip Health and Mobility, Vancouver Coastal Health and Research Institute, Vancouver, British Columbia, Canada.
    Alfredson, Håkan
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Sports Medicine.
    Scott, A
    University of British Columbia, Vancouver, Vancouver Coastal Health and Research Institute.
    Danielson, Patrik
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Anatomy.
    Alpha-2 adrenergic stimulation triggers Achilles tenocyte hypercellularity: comparison between two model systems2013In: Scandinavian Journal of Medicine and Science in Sports, ISSN 0905-7188, E-ISSN 1600-0838, Vol. 23, no 6, p. 687-696Article in journal (Refereed)
    Abstract [en]

    The histopathology of tendons with painful tendinopathy is often tendinosis, a fibrosis-like condition of unclear pathogenesis characterized by tissue changes including hypercellularity. The primary tendon cells (tenocytes) have been shown to express adrenoreceptors (mainly alpha-2A) as well as markers of catecholamine production, particularly in tendinosis. It is known that adrenergic stimulation can induce proliferation in other cells. The present study investigated the effects of an exogenously administered alpha-2 adrenergic agonist in an established in vivo Achilles tendinosis model (rabbit) and also in an in vitro human tendon cell culture model. The catecholamine producing enzyme tyrosine hydroxylase and the alpha-2A-adrenoreceptor (α(2A) AR) were expressed by tenocytes, and alpha-2 adrenergic stimulation had a proliferative effect on these cells, in both models. The proliferation was inhibited by administration of an α(2A) AR antagonist, and the in vitro model further showed that the proliferative alpha-2A effect was mediated via a mitogenic cell signaling pathway involving phosphorylation of extracellular-signal-regulated kinases 1 and 2. The results indicate that catecholamines produced by tenocytes in tendinosis might contribute to the proliferative nature of the pathology through stimulation of the α(2A) AR, pointing to a novel target for future therapies. The study furthermore shows that animal models are not necessarily required for all aspects of this research.

  • 33.
    Backman, Ludvig J
    et al.
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Anatomy.
    Danielson, Patrik
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Anatomy.
    Low range of ankle dorsiflexion predisposes for patellar tendinopathy in junior elite basketball players: a 1-year prospective study2011In: American Journal of Sports Medicine, ISSN 0363-5465, E-ISSN 1552-3365, Vol. 39, no 12, p. 2626-2633Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Patellar tendinopathy (PT) is one of the most common reasons for sport-induced pain of the knee. Low ankle dorsiflexion range might predispose for PT because of load-bearing compensation in the patellar tendon.

    PURPOSE: The purpose of this 1-year prospective study was to analyze if a low ankle dorsiflexion range increases the risk of developing PT for basketball players. STUDY DESIGN: Cohort study (prognosis); Level of evidence, 2.

    METHODS: Ninety junior elite basketball players were examined for different characteristics and potential risk factors for PT, including ankle dorsiflexion range in the dominant and nondominant leg. Data were collected over a 1-year period and follow-up, including reexamination, was made at the end of the year.

    RESULTS: Seventy-five players met the inclusion criteria. At the follow-up, 12 players (16.0%) had developed unilateral PT. These players were found to have had a significantly lower mean ankle dorsiflexion range at baseline than the healthy players, with a mean difference of -4.7° (P = .038) for the dominant limb and -5.1° (P = .024) for the nondominant limb. Complementary statistical analysis showed that players with dorsiflexion range less than 36.5° had a risk of 18.5% to 29.4% of developing PT within a year, as compared with 1.8% to 2.1% for players with dorsiflexion range greater than 36.5°. Limbs with a history of 2 or more ankle sprains had a slightly less mean ankle dorsiflexion range compared to those with 0 or 1 sprain (mean difference, -1.5° to -2.5°), although this was only statistically significant for nondominant legs.

    CONCLUSION: This study clearly shows that low ankle dorsiflexion range is a risk factor for developing PT in basketball players. In the studied material, an ankle dorsiflexion range of 36.5° was found to be the most appropriate cutoff point for prognostic screening. This might be useful information in identifying at-risk individuals in basketball teams and enabling preventive actions. A history of ankle sprains might contribute to reduced ankle dorsiflexion range.

  • 34.
    Bagge, Johan
    et al.
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Anatomy.
    Gaida, JE
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Anatomy. Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Sports Medicine.
    Danielson, Patrik
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Anatomy.
    Alfredson, Håkan
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Sports Medicine.
    Forsgren, Sture
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Anatomy.
    Physical activity level in Achilles tendinosis is associated with blood levels of pain-related factors: a pilot study2011In: Scandinavian Journal of Medicine and Science in Sports, ISSN 0905-7188, E-ISSN 1600-0838, Vol. 21, no 6, p. E430-E438Article in journal (Refereed)
    Abstract [en]

    Physical activity affects the pain symptoms for Achilles tendinosis patients. Brain-derived neurotrophic factor (BDNF), tumor necrosis factor-alpha (TNF-alpha) and their receptors have been detected in human Achilles tendon. This pilot study aimed to compare serum BDNF and soluble tumor necrosis factor receptor I (sTNFRI) levels in Achilles tendinosis patients and healthy controls and to examine the influence of physical activity, and BMI and gender, on these levels. Physical activity was measured with a validated questionnaire, total physical activity being the parameter analyzed. Physical activity was strongly correlated with BDNF among tendinosis women [Spearman's rho (rho) = 0.90, P < 0.01] but not among control women (rho = -0.08, P = 0.83), or among tendinosis and control men. Physical activity was significantly correlated with sTNFRI in the entire tendinosis group and among tendinosis men (rho = 0.65, P = 0.01), but not in the entire control group or among control men (rho = 0.04, P = 0.91). Thus, the physical activity pattern is related to the TNF and BDNF systems for tendinosis patients but not controls, the relationship being gender dependent. This is new information concerning the relationship between physical activity and Achilles tendinosis, which may be related to pain for the patients. This aspect should be further evaluated using larger patient materials.

  • 35.
    Bagge, Johan
    et al.
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Anatomy.
    Lorentzon, Ronny
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Sports Medicine.
    Alfredson, Håkan
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Sports Medicine.
    Forsgren, Sture
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Anatomy.
    Unexpected presence of the neurotrophins NGF and BDNF and the neurotrophin receptor p75 in the tendon cells of the human Achilles tendon2009In: Histology and Histopathology, ISSN 0213-3911, E-ISSN 1699-5848, Vol. 24, no 7, p. 839-848Article in journal (Refereed)
    Abstract [en]

    Neurotrophins are substances that have been shown to be important in growth and remodelling phases in different types of tissue. There is no information concerning the possible occurrences of neurotrophins and their receptors in tendons. In this study, sections of both chronic painful (tendinosis) and pain-free (non-tendinosis) human Achilles tendons were immunohistochemically stained with antibodies against the neurotrophins NGF and BDNF, and their receptors TrkA, TrkB and p75. There were marked immunoreactions for NGF and BDNF in the tendon cells (tenocytes) of both tendinosis and non-tendinosis specimens. The tenocytes were also reactive for the receptor p75, but not for the receptors TrkA and TrkB. In addition, p75 immunoreactions were seen in nerve fascicles and in the walls of arterioles. This is the first study to identify neurotrophins in the tenocytes of human tendon. It is clear from this study that the local cells of tendons are sources of neurotrophins. The neurotrophins may play an important role in the tendon through their interaction with the receptor p75 in the tenocytes. These interactions may regulate tropic modulatory, and apoptotic effects. In conclusion, the observations show a new concept concerning production and function of neurotrophins, namely in the tenocytes of tendons.

  • 36.
    Ballin, Marcel
    et al.
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Sports medicine.
    Lundberg, Emmy
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Sports medicine.
    The effect of 10 weeks of vigorousintensity interval training on visceral adipose tissue in 70-year-old individuals with central obesity: - a randomized controlled trial2018Independent thesis Basic level (degree of Bachelor), 180 HE creditsStudent thesis
  • 37. Baoren, Che
    et al.
    Ji-Guo, Yu
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Sports Medicine.
    Aging effects of exercise training on erythrocyte1995In: Journal of Shanghai Physical Education Institute, ISSN 1000-5498, Vol. 19, no S1, p. 102-104Article in journal (Refereed)
    Abstract [zh]

    长时间剧烈运动能引起循环中的红细胞损伤和老化;而长期运动训练有可能导致运动性贫血的发生,据最近的一些研究表明,尽管一次长时间剧烈运动可引起红细胞被破坏增多,但长期运动训练引起的运动性贫血,在很多情况下属于血液稀释作用造成的。本文设计6周身体训练并在训练的不同阶段进行剧烈运动,测定反映红细咆老化状态的几个敏感指标:2,3—DPG、红细胞肌酸含量及红细胞生成素等,旨在确认不同强度的训练及剧烈运动对红细胞生成和老化的影响,为进一步完善运动性贫血理论提供依据。

  • 38.
    Bengtsson, Victor
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Sports Medicine.
    Acute effects of different warm-uproutines on peak torque2014Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
  • 39.
    Bengtsson, Victor
    et al.
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Sports medicine.
    Yu, Ji-Guo
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Sports medicine.
    Gilenstam, Kajsa
    Could the negative effects of static stretching in warm-up be restored by sport specific exercise?2017In: Journal of Sports Medicine and Physical Fitness, ISSN 0022-4707, E-ISSN 1827-1928, ISSN 0022-4707Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Static stretching (SS) is widely used in warm-up as it is generally believed to increase mobility and reduce the risk of injury; however, SS has been shown to induce transient negative effects on subsequent muscle performance. Interestingly, recent studies have shown that sport specific exercise could restore SS-induced negative effects on certain sports, especially of explosive muscular performance. Whether sport specific exercise could restore SS-induced negative effects on isokinetic muscle performance remains unclear.

    METHODS: The present study conducted two different warm-ups: 2-component warm-up and 3-component warm-up on 15 university students. Both protocols contained low intensity aerobic exercise and sport specific exercise, whereas the 3-component warm-up also contained SS which has been previously proven to induce negative effects on subsequent muscle performance. After the warm-ups, the subjects performed an isokinetic test on a Biodex. To make the sport specific exercise mimic the subsequent test, both included concentric isokinetic knee extension. During the tests, muscle performance of peak torque, mean power, and total work was recorded. Comparison of the measurements on each parameter between the two warm-ups was performed using paired t test.

    RESULTS: The comparisons did not reveal any significant difference in the measurement of any parameter between the two different warm-up protocols, and calculation of Cohen's revealed small effect sizes on all of the three variables.

    CONCLUSIONS: On basis of the present results and that the SS could induce transient negative effects on subsequent muscle performance, we concluded that the negative effects of the SS on the variables were restored by the isokinetic contractions.

  • 40.
    Bergström, Emma
    et al.
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Sports medicine.
    Offerman, Jens
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Sports medicine.
    Unga kvinnors järnstatus i relation till aerob metabolism under cykelarbete.2018Independent thesis Basic level (degree of Bachelor), 180 HE creditsStudent thesis
    Abstract [en]

    Introduction: Iron is an essential trace mineral whose main function in the body is to produce hemoglobin, a transport molecule for oxygen and carbon dioxide. Iron deficiency is the most common nutritional deficiency in athletes and women are at particular risk of becoming iron deficient.  Objective: Examine the iron status of athletic women and the possible relation to 1) aerobic metabolism, 2) efficacy, and 3) VO2max during cycling workload  Method: Descriptive cross-sectional study. The participants mean age is 22±5,8 year, mean VO2max 43,5 ±4,6 ml/kg/min. Iron status was compared to oxygen consumption, efficacy and VO2max during a ergometer cycle test. Blood samples with analysis of the participants serum ferritin (sFer) with a cut off value of <29 ug/l were considered as low and >30 ug/l were considered as normal iron status. A submaximal and maximal ergometer cycle test was conducted on the participants. Analysis was done in form of regression analysis in JMP 13, in order to try to predict a relationship. Result: No relationship was found between the different parameters that have been compared. SFer of participants (n=48) was an average of 23±11 ug/l. SFer and VO2/l/min at 100 watts (r2=.09, P<0.05), sFer and kcal/min (r2=0.05, sFer and sFer and VO2max (r2=0.05). Conclusion: The main findings is that iron status does not have a significant relationship with aerobic metabolism, although previous research has suggested such. More participants with bigger value of ferritin and a clearer standardization around the training, diet and menstrual cycle of the women compared could have given another result.   

  • 41.
    Bjur, Dennis
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Sports Medicine.
    Danielson, Patrik
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Anatomy.
    Alfredson, Håkan
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Sports Medicine.
    Forsgren, Sture
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Anatomy.
    Observations in favor of a presence of local catecholamine production in the human Achilles tendon - of importance when understanding potential adrenergic effects in Achilles tendinosis.2006Conference paper (Refereed)
    Abstract [en]

    The mid-portion of the Achilles tendon is a frequently injured and pathologically affected tendon region. Achilles tendinosis presents with chronic tendon pain and impaired function, and most often occurs in the mid-portion of the tendon. Nerve-related effects are likely to be of great significance in the pathogenesis of this condition, and information on innervation patterns is therefore of importance. However, the available information on these aspects is limited for the human Achilles tendon. Via staining for a general nerve marker it has previously been shown that there is a presence of innervation in the loose paratendinous connective tissue and to some extent also within the tendon tissue proper. This innervation has been found to partly conform to sensory innervation. There is no information at all on the patterns of sympathetic innervation in the human Achilles tendon. This is a drawback as it is crucial to know the basis for adrenergic effects on blood vessel regulation in tendinosis and as efferent sympathetic nerve activities may be related to pain symptoms. In the present study, therefore, specimens of tendon tissue from the human Achilles tendon of both tendinosis patients and normal controls were immunohistochemically examined concerning expression of the rate limiting enzyme in catecholamine production, tyrosine hydroxylase (TH), and of neuropeptide Y (NPY). In normal tendons, TH- and NPY-immunoreactive nerve fibers were occasionally detected in nerve fascicles and in arterial walls in the paratendinous tissue, but were not detected with certainty within the tendon tissue proper. In the specimens of tendinosis affected tendons, TH-and NPY-immunoreactive nerve fibers were almost non-existent. Surprisingly, however, TH-immunoreactions could be seen in the tendon cells (tenocytes) themselves. Sections were also processed for demonstration of α1-, α2a-, and β1- adrenoreceptors. It was hereby seen that there were immunoreactions for adrenergic receptors in the walls of some of the blood vessels, as well as in some of the tenocytes. The observations show that there is a limited sympathetic innervation at the level of the paratendinous tissue and in principle a non-existent such innervation within the tendon tissue proper. On the other hand, as evidenced by findings of TH-immunoreaction in tenocytes, it appears as if there is a local production of catecholamines within the tendon tissue proper itself. Thus, the tenocytes might be an important source of mediators that bind to the adrenergic receptors in the tissue. The observations of adrenergic receptors on tenocytes are furthermore of interest as adrenergic stimulation in other situations can lead to degenerative/apoptotic events and an affection on cell growth. These facts are thus highly interesting when trying to understand how such events can occur in Achilles tendinosis. Similarly, cartilage and menisci have in recent studies been found to harbor cells that express adrenergic receptors, but nevertheless to be very scarcely equipped with nerves. Although there is a very limited sympathetic innervation in the Achilles tendon, our observations show that there is a morphologic correlate for the occurrence of adrenergic actions in the tendon, via effects of locally produced catecholamines.

  • 42.
    Björklund, Martin
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Sports Medicine.
    Djupsjöbacka, Mats
    Crenshaw, Albert G
    Acute muscle stretching and shoulder position sense2006In: Journal of athletic training, ISSN 1062-6050, E-ISSN 1938-162X, Vol. 41, no 3, p. 270-274Article in journal (Refereed)
    Abstract [en]

    Context: Stretching is common among athletes as a potential method for injury prevention. Stretching-induced changes in the muscle spindle properties are a suggested mechanism, which may imply reduced proprioception after stretching; however, little is known of this association.

    Objective: To evaluate whether acute stretching of the shoulder muscles affects position sense.

    Design: A crossover design with subjects randomized to 3 groups.

    Setting: A university human research laboratory. Patients or Other Participants: Nine male (age = 24 +/- 3 years) and 9 female (age = 21 +/- 2 years) healthy volunteers.

    Intervention(s): Stretching of shoulder (1) agonists or (2) antagonists or (3) nonstretching control.

    Main Outcome Measure(s): We determined position sense acuity of the right shoulder before and after the interventions by having subjects attempt to reproduce arm positions of 15 degrees and 30 degrees (shoulder adduction) while starting at 45 degrees to the sagittal plane. The outcome variables were response variability (variable error) and overall accuracy (absolute error).

    Results: The relative change in variable error (ie, variable error after/variable error before) was not significantly different between the interventions ( P = .38). Similarly, no change in absolute error was found ( P = .76). Furthermore, no differences were noted regarding test sequence or the interaction of intervention x sequence for either variable error ( P = .73 and .53, respectively) or absolute error ( P = .71 and .67, respectively).

    Conclusions: We found no effect on shoulder position sense after an acute bout of stretching of either agonist or antagonist shoulder muscles.

  • 43.
    Blombäck, Erik
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Sports Medicine.
    Samband mellan testosteron, DHEAS, kroppskomposition och fysiska kapaciteter hos unga kvinnliga fotbollsspelare2013Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Testosterone is a steroid and anabolic hormone found in all mammals. Previous research indicates that testosterone levels correlates with physical capacities related to physical performance. However, these studies refers only to men and boys. The aim of present study was therefore to investigate the potential relationship between body composition, strength, power and endurance capabilities in relation to blood levels of testosterone and DHEAS in young female football players. Seventeen female elite football (age: 15,4 ± 0,6, body mass: 57,2 ± 7,4kg, height 1,65 ±0,04m) players volunteered for the study. Morning levels of testosterone were plotted against results of Dual-energy X-ray absorptiometry, Biodex isokinetic dynamometer, maximal counter movement jump, drop jump, 10 and 20 meters sprints and aerobic fitness (Yo-Yo intermittent endurance test). Testosterone levels were significant correlated with DHEAS as well as bone density (BMD) in L1-L4 (p <0,01) and whole body (WB) BMD (p <0,05). DHEAS also correlated with BMD in L1-L4 and WB (p <0,05). No correlations were found between testosterone, DHEAS and performance capacities. These results suggest that DHEAS predict the level of testosterone and BMD in young women. However, more research is needed to clarify the relationship between testosterone, DHEAS and physical capacities in a larger group of women.

  • 44.
    Bodin, Jimmy
    et al.
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Sports medicine.
    Eklund, Viktor
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Sports medicine.
    En jämförelse av den fysiska kapaciteten mellan kvinnliga och manliga fotbollsspelare2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Football (or soccer) is a physically complex sport that involves everything from kicking, running, throwing, tackling etc. Even if most of the participants are men, more and more women are playing. As many know there are general differences between genders. A common knowledge is that men are stronger and have higher aerobic capacity. Therefore the purpose of this study was to investigate gender differences in football. 32 experienced football players participated in this study. 17 men (mean age: 22,7 ± 3,5 years, bodyweight: 79,4 ± 7,4kg) and 17 women (mean age: 22,1 ± 3,3 years, bodyweight: 65,2 ± 8,4 kg). The women play in the Swedish first division while men are playing in the Swedish third division. Subjects were tested in endurance (Yo- Yo Intermittent Endurance level 2 test), jumping ability  (Squat jump (SJ), Countermovement jump without (CMJ) and with arm swing (CMJ (a)) and sprinting ability (10 meter sprint). The result shows none significant differences between the two teams. The most differences were found in the Yo- Yo IE2 test where the men ran 2321 ± 605m in contrast to the women 1965± 505m (p=0,07).  In the sprint testes the men ran 10 meters at 1,77± 0,1s and the women 1,79± 0,1s (p=0,57). At the vertical jump testes the result where in SJ for men 33,2 ± 3,3 and women 31,2 ± 5,2 cm (p=0,11), In CMJ the men performed 35,9 ±5,2 cm and women 33,1±3,6 cm (p=0,10) and in CMJ (a) the men performed 40,0 ±7,3 cm and the women 40,0 ± 3,5 cm (p=0,98). In conclusion the men and women have a similar physical capacity since there were no significant differences found. This could be a result from different training structures or the different physical demands varying from the two divisions.

  • 45.
    Bogdanis, Gregory C.
    et al.
    Faculty of Physical Education & Sports Science, University of Athens.
    Papaspyrou, Aggeliki
    Faculty of Physical Education & Sports Science, University of Athens.
    Souglis, Athanasios
    Faculty of Physical Education & Sports Science, University of Athens.
    Theos, Apostolos
    Faculty of Physical Education & Sports Science, University of Athens.
    Sotiropoulos, Aristomenis
    Faculty of Physical Education & Sports Science, University of Athens.
    Maridaki, Maria
    Faculty of Physical Education & Sports Science, University of Athens.
    Effects of a hypertrophy and a maximal training program on speed, force and power of soccer players2008In: Science and Football, VI: The Proceedings of the Sixth World Congress on Science and Football / [ed] Tom Reilly and Feza Korkusuz, Routledge, 2008, p. 290-295Chapter in book (Refereed)
  • 46.
    Bogdanis, Gregory C.
    et al.
    Faculty of Physical Educaation & Sports Science, University of Athens.
    Papaspyrou, Aggeliki
    Faculty of Physical Educaation & Sports Science, University of Athens.
    Souglis, Athanasios
    Faculty of Physical Educaation & Sports Science, University of Athens.
    Theos, Apostolos
    Faculty of Physical Educaation & Sports Science, University of Athens.
    Sotiropoulos, Aristomenis
    Faculty of Physical Educaation & Sports Science, University of Athens.
    Maridaki, Maria
    Faculty of Physical Educaation & Sports Science, University of Athens.
    Effects of two different half-squat training programs on fatigue during repeated cycling sprints in soccer players2011In: Journal of Strength and Conditioning Research, ISSN 1064-8011, E-ISSN 1533-4287, Vol. 5, no 7, p. 1849-1856Article in journal (Refereed)
    Abstract [en]

    This study compared the effects of two different half-squat training programs on the repeated-sprint ability of soccer players during the preseason. Twenty male professional soccer players were divided into 2 groups: One group (S-group) performed 4 sets of 5 repetitions with 90% of their 1-repetition maximum (1RM), and the other group (H-group) performed 4 sets of 12 repetitions with 70% of 1RM, 3 times per week for 6 weeks, in addition to their common preseason training program. Repeated-sprint ability was assessed before and after training by 10 × 6-second cycle ergometer sprints separated by 24 seconds of passive recovery. Maximal half-squat strength increased significantly in both groups (p < 0.01), but this increase was significantly greater in the S-group compared with the H-group (17.3 ± 1.9 vs. 11.0 ± 1.9%, p < 0.05). Lean leg volume (LLV) increased only in the H-group. Total work over the 10 sprints improved in both groups after training, but this increase was significantly greater in the second half (8.9 ± 2.6%) compared with the first half of the sprint test (3.2 ± 1.7%) only in the S-group. Mean power output (MPO) expressed per liter of LLV was better maintained during the last 6 sprints posttraining only in the S-group, whereas there was no change in MPO per LLV in the H-group over the 10 sprints. These results suggest that resistance training with high loads is superior to a moderate-load program, because it increases strength without a change in muscle mass and also results in a greater improvement in repeated sprint ability. Therefore, resistance training with high loads may be preferable when the aim is to improve maximal strength and fatigue during sprinting in professional soccer players.

  • 47.
    Bogdanis, Gregory C.
    et al.
    Faculty of Physical Education & Sport Science, Uniersity of Athens.
    Papaspyrou, Aggeliki
    Faculty of Physical Education & Sport Science, Uniersity of Athens.
    Theos, Apostolos
    Faculty of Physical Education & Sport Science, Uniersity of Athens.
    Maridaki, Maria
    Faculty of Physical Education & Sport Science, Uniersity of Athens.
    Influence of resistive load on power output and fatigue during intermittent sprint cycling exercise in children2007In: European Journal of Applied Physiology, ISSN 1439-6319, E-ISSN 1439-6327, Vol. 101, no 3, p. 313-320Article in journal (Refereed)
    Abstract [en]

    This study examined the effects of two resistive loads on fatigue during repeated sprints in children. Twelve 11.8 (0.2) year old boys performed a force-velocity test to determine the load (Fopt) corresponding to the optimal pedal rate. On two separate occasions, ten 6-s sprints interspersed with 24-s recovery intervals were performed on a friction-loaded cycle ergometer, against a load equal to Fopt or 50%Fopt. Although mean power output (MPO) was higher in the Fopt [397 (24) and 356 (19) W, P < 0.01], the decline in MPO over the 10 sprints was similar in Fopt [8.8 (1.9) %] and 50%Fopt [9.0 (2.4) %]. In contrast, peak power (PPO) was not different in sprint 1 between the two conditions [459 (24) and 460 (28) W], but was decreased only in 50%Fopt [11.4 (3.2) %, P < 0.01], while it was maintained in the Fopt despite the higher total work during each sprint. Fatigue within each sprint (percent drop from peak to end power output) was also higher in the 50%Fopt compared with the Fopt [32 (2.5) vs. 10 (1.6) %, P < 0.01]. Peak and mean pedal rate in Fopt condition were close to the optimum (Vopt), while a large part of the sprint time in 50%Fopt was spent far from Vopt. The present study shows that sprinting against Fopt reduces fatigue within and between repeated short sprints in children. It is suggested that fatigue during repeated sprints is modified when pedal rate is not close to Vopt, according to the parabolic power versus pedal rate relationship.

  • 48.
    Bramell, Axel
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Sports medicine.
    Differences in the relationship of heart rate and blood lactate values between running on track versus inclined treadmill: Improving laboratory testing to accurately prescribe exercise intensities2016Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The purpose of the study was to evaluate the generalisability of the heart rate-blood lactate relationship determined in laboratory testing in comparison to running over ground. This plays a crucial role to prescribe exercise intensity from laboratory results. Ten well trained runners performed a maximal oxygen uptake (VO2max) pre-test and an incremental submaximal test performed at a two degrees inclined treadmill and a running track. Statistical analysis included student’s t-test of heart rate at interpolated blood lactate levels and comparison of second order polynomial regression lines. VO2max was 60,4 ± 6 ml/kg/min for men and 56,3 ± 4,3 ml/kg/min for women. There was no significant difference in heart rate at interpolated blood lactate of 3 and 4 mmol/L. There was no significant difference between heart rate values at any running velocity. A significant difference between blood lactate values was observed 14km/h (p=0,04). When considering blood lactate values up to 6mmol/L, heart rate-blood lactate relationships were similar. In conclusion, lactate threshold testing on treadmill through incremental test protocols on a two degrees incline gives similar heart rate- blood lactate relationship as running over ground and may be used to prescribe intensity in training performed over ground. 

  • 49.
    Bramell, Axel
    et al.
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Sports medicine.
    Jakobsson, Johan
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Sports medicine.
    Validation and practical evaluation of the Onesenz microdialysis lactate analyser2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This study investigated the reliability of the new Onesenz on-line microdialysis lactate analyser compared to the YSI 2300 Stat Plus. Venous blood lactate concentrations were measured simultaneously with both analysers during an incremental cycle ergometer test. Eight physically active men and women completed the test to voluntary exhaustion. A total of 81 blood samples from both devices were included in the analysis. Statistical analysis was conducted through correlation, regression analysis and limits of agreement. Lactate values during graded exercise ranged from 0,5 mM/l to 14,1 mM/l. A significant correlation was observed between the two analysers, r(79)=0,98, p<0,001. Regression analysis determined the equation: [Onesenz] = 0,811*[YSI] + 0,345  and coefficient of determination (R2) was 0,95. The mean difference between the analysers was 0,15 mM/l ± 0,7 mM/l. The agreement between the two analysers deteriorated above 6 mM/l. When studying bLa values above 6 mM/l the mean difference was 1,38 ± 1,3 mM/l. In conclusion, the Onesenz lactate analyser provides reliable bLa measurements up to 6 mM/l compared to the YSI 2300. In the context of sports medicine the more time consuming method of microdialysis limits its appropriateness to longer test protocols, but on the other hand reduces human error. Still, the prototype lacks several features concerning practical usefulness.

    Keywords: Blood lactate, Microdialysis, Lactate threshold, Exercise testing, Lactate analyser

  • 50.
    Bredemo, Claes
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Sports Medicine.
    RSA-testet: ett fystest för innebandyspelare.: - En 7-veckors interventionsstudie på kvinnliga innebandyspelare.2013Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    AIM: The aim of this study was to determine if the repeated sprint ability test (RSA-test) could be used to measure the repeated sprint ability for female floorball players and if a 7 weeks training intervention could improve the RSA-result. The intervention group was analyzed for the number of ball contacts to study if the RSA-test could be used to measure match performance.

    METHODS: Two female floorball teams (intervention group, n=16, 16,9 ±0,9 years, control group, n=10, 18,7 ±3,6 years) participated in the study. The intervention group performed seven training weeks of sprint- and repeated sprint training. Before and after the 7 week intervention both groups conducted a RSA-test of 6x40m (2x20m) all-out sprints, interspersed with 25 s of a passive recovery. Two games were recorded with a video camera in the intervention group and the number of ball contacts was analyzed.

    RESULTS: There was no significant difference in the base line values of the RSA-test between the two groups. There was a significant improvement between the intervention groups baseline and follow up values in RSA mean time (p <0,01) and RSA best time (p<0,01). There was no significant improvement in the control group. Between the two groups there was a significant difference in RSA mean time (p <0,05) for the intervention group. The number of ball contacts was unchanged after the intervention period.

    CONCLUSION: The completed 7 week intervention proved that repeated sprint training in combination with single sprint training is a way to improve the RSA mean time and RSA best time in this group of floorball players. The RSA-test could not prove any match performance, measured as ball contacts.

    Key words: Floorball, repeated sprint ability, sprint training, match performance,

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