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  • 1.
    Andersson, Nina
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    Grip, Helena
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Sjukgymnastik.
    Lindvall, Peter
    Umeå universitet, Medicinska fakulteten, Institutionen för farmakologi och klinisk neurovetenskap, Klinisk neurovetenskap.
    Koskinen, Lars-Owe D
    Umeå universitet, Medicinska fakulteten, Institutionen för farmakologi och klinisk neurovetenskap, Klinisk neurovetenskap.
    Brändström, Helge
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Malm, Jan
    Umeå universitet, Medicinska fakulteten, Institutionen för farmakologi och klinisk neurovetenskap, Klinisk neurovetenskap.
    Eklund, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för farmakologi och klinisk neurovetenskap, Klinisk neurovetenskap.
    Air transport of patients with intracranial air: computer model of pressure effects2003Ingår i: Aviation, Space and Environmental Medicine, ISSN 0095-6562, E-ISSN 1943-4448, Vol. 74, nr 2, s. 138-144Artikel i tidskrift (Refereegranskat)
  • 2.
    Brändström, Helge
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Grip, Helena
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Hallberg, Per
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Grönlund, Christer
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Ängquist, Karl-Axel
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Kirurgi.
    Giesbrecht, Gordon G
    Hand cold recovery responses before and after 15 months of military training in a cold climate2008Ingår i: Aviation, Space and Environmental Medicine, ISSN 0095-6562, E-ISSN 1943-4448, Vol. 79, nr 9, s. 904-908Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    INTRODUCTION: The ability of fingers to rapidly rewarm following cold exposure is a possible indicator of cold injury protection. We categorized the post-cooling hand-rewarming responses of men before and after participation in 15 mo of military training in a cold environment in northern Sweden to determine: 1) if the initial rewarming category was related to the occurrence of local cold injury during training; and 2) if cold training affected subsequent hand-rewarming responses. METHODS: Immersion of the dominant hand in 10 degrees C water for 10 min was performed pre-training on 77 men. Of those, 45 were available for successful post-training retests. Infrared thermography monitored the dorsal hand during 30 min of recovery. Rewarming was categorized as normal, moderate, or slow based on mean fingertip temperature at the end of 30 min of recovery (TFinger,30) and the percentage of time that fingertips were vasodilated (%VD). RESULTS: Cold injury occurrence during training was disproportionately higher in the slow rewarmers (four of the five injuries). Post-training, baseline fingertip temperatures and cold recovery variables increased significantly in moderate and slow rewarmers: TFinger30 increased from 21.9 +/- 4 to 30.4 +/- 6 degrees C (Moderate), and from 17.4 +/- 0 to 22.3 +/- 7 degrees C (Slow); %VD increased from 27.5 +/- 16 to 65.9 +/- 34% (Moderate), and from 0.7 +/- 2 to 31.7 +/- 44% (Slow). CONCLUSIONS: Results of the cold recovery test were related to the occurrence of local cold injury during long-term cold-weather training. Cold training itself improved baseline and cold recovery in moderate and slow rewarmers.

  • 3.
    Brändström, Helge
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Wiklund, Urban
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Karlsson, Marcus
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Ängquist, Karl-Axel
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Kirurgi.
    Grip, Helena
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Haney, Michael
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Autonomic nerve system responses for normal and slow rewarmers after hand cold provocation: effects of long-term cold climate training2013Ingår i: International Archives of Occupational and Environmental Health, ISSN 0340-0131, E-ISSN 1432-1246, Vol. 86, nr 3, s. 357-365Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    PURPOSE: Differences among individuals concerning susceptibility to local cold injury following acute cold exposure may be related to function of the autonomic nervous system. We hypothesized that there are differences in heart rate variability (HRV) between individuals with normal or more pronounced vasoconstriction following cold exposure and that there is an adaptation related to prolonged cold exposure in autonomic nervous system response to cold stimuli.

    METHODS: Seventy-seven young men performed a cold provocation test, where HRV was recorded during cold hand immersion and recovery. Forty-three subjects were re-examined 15 months later, with many months of cold weather training between the tests. Subjects were analyzed as 'slow' and 'normal' rewarmers according to their thermographic rewarming pattern.

    RESULTS: For the 'pre-training' test, before cold climate exposure, normal rewarmers had higher power for low-frequency (P(LF)) and high-frequency (P(HF)) HRV components during the cold provocation test (ANOVA for groups: p = 0.04 and p = 0.005, respectively). There was an approximately 25 % higher P(HF) at the start in normal rewarmers, in the logarithmic scale. Low frequency-to-high frequency ratio (P(LF)/P(HF)) showed lower levels for normal rewarmers (ANOVA for groups: p = 0.04). During the 'post-training' cold provocation test, both groups lacked the marked increase in heart rate that occurred during cold exposure at the 'pre-training' setting. After cold acclimatization (post-training), normal rewarmers showed lower resting power values for the low-frequency and high-frequency HRV components. After winter training, the slow rewarmers showed reduced low-frequency power for some of the cold provocation measurements but not all (average total P(LF), ANOVA p = 0.05), which was not present before winter training.

    CONCLUSIONS: These HRV results support the conclusion that cold adaptation occurred in both groups. We conclude that further prospective study is needed to determine whether cold adaptation provides protection to subjects at higher risk for cold injury, that is, slow rewarmers.

  • 4. Ertzgaard, Per
    et al.
    Öhberg, Fredrik
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Gerdle, Björn
    Grip, Helena
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    A new way of assessing arm function in activity using kinematic Exposure Variation Analysis and portable inertial sensors - A validity study2016Ingår i: Manual Therapy, ISSN 1356-689X, E-ISSN 1532-2769, Vol. 21, s. 241-249Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Portable motion systems based on inertial motion sensors are promising methods, with the advantage compared to optoelectronic cameras of not being confined to a laboratory setting. A challenge is to develop relevant outcome measures for clinical use. The aim of this study was to characterize elbow and shoulder motion during functional tasks, using portable motion sensors and a modified Exposure Variation Analysis (EVA) and evaluate system accuracy with optoelectronic cameras. Ten healthy volunteers and one participant with sequel after stroke performed standardised functional arm tasks. Motion was registered simultaneously with a custom developed motion sensor system, including gyroscopes and accelerometers, and an optoelectronic camera system. The EVA was applied on elbow and shoulder joints, and angular and angular velocity EVA plots was calculated. The EVA showed characteristic patterns for each arm task in the healthy controls and a distinct difference between the affected and unaffected arm in the participant with sequel after stroke. The accuracy of the portable system was high with a systematic error ranging between -1.2 degrees and 2.0 degrees. The error was direction specific due to a drift component along the gravity vector. Portable motion sensor systems have high potential as clinical tools for evaluation of arm function. EVA effectively illustrates joint angle and joint angle velocity patterns that may capture deficiencies in arm function and movement quality. Next step will be to manage system drift by including magnetometers, to further develop clinically relevant outcome variables and apply this for relevant patient groups.

  • 5.
    Fredrik, Öhberg
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    Grip, Helena
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    Nilsson, Kjell G
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Ortopedi.
    Edström, Urban
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    Gustavsson, Ola
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    Häger, Charlotte
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Sjukgymnastik.
    Lundström, Ronnie
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper. Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin.
    Gait analysis using a portable motion sensor system: measurements in subjects with hip implant as compared with healthy controls2013Ingår i: Gait & Posture, ISSN 0966-6362, E-ISSN 1879-2219, Vol. 38, nr suppl 1, s. 99-100Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Introduction: There is an increase of age related diseases such as hip joint arthritis, something that is often treated with hip replacement surgery. The aim of this study was to quantify movement function and its effect on quality of life in persons treated with hip implant, in comparison to matched asymptomatic controls.

    Patients/Materials and Methods: This is an ongoing study, and so far, 2 asymptomatic subjects (CTRL, age 50 ± 13 years, BMI 23 ± 2), and 4 subjects with hip implant (HIP, age 51 ± 15 years, BMI 25 ± 3), have been analyzed. The HIP group received their implant 2.6 ± 1.1 years ago and finished their rehabilitation 1.6 ± 1.1 years ago. Hip dysfunction and Osteoarthritis Outcome Score (HOOS) was used to assess the subject's hip function and its associated problems. A functional calibration (flexion/abduction movements) was done and each subject then performed 5 repetitions of gait (approx. 25 left/right gait cycles). Movement was registered with a custom-developed portable motion sensor system, where each sensor consisted of a tri-axial accelerometer and gyroscope. Sensors were placed on pelvis and each thigh and shank. Further calculations were done in MATLAB (v7.12 R2011a, Mathworks). Cosine rotation matrices were extracted by functional sensor-to- segment-calibration and sensor fusion [1], and hip and knee angles were obtained as Euler angles.

    Results: Preliminary results indicated larger range in hip rotation and smaller range of knee flexion during gait in HIP group than in the CTRL group (Fig. 1). HOOS profile (Fig. 2) indicated that hip function during sports (SP) and the general quality of life (QOL) were lower in the HIP group.

    Fig. 1. 

    Mean and SD of hip and knee angle over 15 gait cycles in one HIP subject (blue) as compared with the CTRL group (black). (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

    Figure optionsFig. 2. 

    HOOS profiles in HIP (blue square) and CTRL group (black). (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

    Figure options

    Discussion and conclusions: Motion patterns during gait seemed to be negatively affected in subjects with hip implant, even after the rehabilitation program was completed and even though the HOOS profiles indicated a relative good hip function.

    Reference

    • [1]
    • J. Favre, B.M. Jolles, O. Siegrist, K. Aminian
    • Quaternion-based fusion of gyroscopes and accelerometers to improve 3D angle measurement

  • 6. Frykberg, G.
    et al.
    Johansson, Gudrun
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Grip, Helena
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Selling, Jonas
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Häger, Charlotte
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Sjukgymnastik.
    The “Arm Posture Score” for assessment of arm swing during gait: Evaluation of additional rotational components and different gait speeds2012Konferensbidrag (Övrigt vetenskapligt)
  • 7.
    Grip, Helena
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    Biomechanical assessment of head and neck movements in neck pain using 3D movement analysis2008Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Three-dimensional movement analysis was used to evaluate head and neck movement in patients with neck pain and matched controls. The aims were to further develop biomechanical models of head and neck kinematics, to investigate differences between subjects with non-specific neck pain and whiplash associated disorders (WAD), and to evaluate the potential of objective movement analysis as a decision support during diagnosis and follow-up of patients with neck pain.

    Fast, repetitive head movements (flexion, extension, rotation to the side) were studied in a group of 59 subjects with WAD and 56 controls. A back propagation artificial neural network classified vectors of collected movement variables from each individual according to group membership with a predictivity of 89%. The helical axis for head movement were analyzed in two groups of neck pain patients (21 with non-specific neck pain and 22 with WAD) and 24 matched controls. A moving time window with a cut-off angle of 4° was used to calculate finite helical axes. The centre of rotation of the finite axes (CR) was derived as the 3D intersection point of the finite axes. A downward migration of the axis during flexion/extension and a change of axis direction towards the end of the movements were observed. CR was at its most superior position during side rotations and at its most inferior during ball catching. This could relate to that side rotation was mainly done in the upper spine, while all cervical vertebrae were recruited to stabilize the head in the more complex catching task. Changes in movement strategy were observed in the neck pain groups: Neck pain subjects had lower mean velocities and ranges of movements as compared with controls during ball catching, which could relate to a stiffer body position in neck pain patients in order to stabilize the neck. In addition, the WAD group had a displaced axis position during head repositioning after flexion, while CR was displaced during fast side rotations in the non-specific neck pain group. Pain intensity correlated with axis and CR position, and may be one reason for the movement strategy changes.

    Increased amount of irregularities in the trajectory of the axis was found in the WAD group during head repositioning, fast repetitive head movements and catching. This together with an increased constant repositioning error during repositioning after flexion indicated motor control disturbances. A higher group standard deviation in neck pain groups indicated heterogeneity among subjects in this disturbance.

    Wireless motion sensors and electro-oculography was used simultaneously, as an initial step towards a portable system and towards a method to quantify head-eye co-ordination deficits in individuals with WAD. Twenty asymptomatic control subjects and six WAD subjects with eye disturbances (e.g. dizziness and double vision) were studied. The trial-to-trial repeatability was moderate to high for all evaluated variables (single intraclass correlation coefficients >0.4 in 28 of 32 variables). The WAD subjects demonstrated decreased head velocity, decreased range of head movement during gaze fixation and lowered head stability during head-eye co-ordination as possible deficits.

    In conclusion, kinematical analyses have a potential to be used as a support for physicians and physiotherapists for diagnosis and follow-up of neck pain patients. Specifically, the helical axis method gives information about how the movement is performed. However, a flexible motion capture system (for example based on wireless motion sensors) is needed. Combined analysis of several variables is preferable, as patients with different neck pain disorders seem to be a heterogeneous group.

  • 8.
    Grip, Helena
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Sjukgymnastik.
    Häger, Charlotte
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering.
    A new approach to measure functional stability of the knee based on changes in knee axis orientation2013Ingår i: Journal of Biomechanics, ISSN 0021-9290, E-ISSN 1873-2380, Vol. 46, nr 5, s. 855-862Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    There is a lack of measures that quantify functional knee stability, which is of particular relevance in knee rehabilitation. Therefore, the aim of this study was to investigate the usefulness of knee finite helical axis (FHA) variables in 33 healthy subjects during two different functional tasks; One leg side hop (SH) and Two Leg Squat (TLS), and to investigate correlations of these variables with laxity. Laxity was assessed with a KT-1000 arthrometer and the Beighton Hypermobility Score. Movements were registered with an optical motion capture system. Knee rotation and translation were defined by a six degree of freedom segment model. FHA was calculated for finite steps of 20 degrees knee flexion, based on error simulations. We computed the FHA inclination, the translation along FHA and an FHA Direction Index quantifying directional changes. All variables were repeatable (average ICCs similar to 0.97 during TLS and similar to 0.83 during SH). The lower functional knee stability in SH was reflected by a significantly higher FHA Direction Index and a larger medio-lateral FHA inclination compared to those in TLS. The superior-inferior inclination was smaller during Landing in SH compared to Take-Off and TLS. Translation along FHA was generally small as expected in healthy subjects. Beighton Hypermobility Score and KT-1000 values had weak but significant correlations with FHA Direction Index and FHA translation, which show that laxity influences the functional knee stability. We conclude that FHA measures were sensitive enough to discriminate between SH and TLS. The next step is to investigate the usability of these measures in subjects with knee injury.

  • 9.
    Grip, Helena
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper. Umeå universitet, Samhällsvetenskapliga fakulteten, Enheten för demografi och åldrandeforskning (CEDAR).
    Johansson, Anna-Maria
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi. Umeå universitet, Samhällsvetenskapliga fakulteten, Enheten för demografi och åldrandeforskning (CEDAR).
    Selling, Jonas
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi. Umeå universitet, Samhällsvetenskapliga fakulteten, Enheten för demografi och åldrandeforskning (CEDAR).
    Rönnqvist, Louise
    Umeå universitet, Samhällsvetenskapliga fakulteten, Institutionen för psykologi. Umeå universitet, Samhällsvetenskapliga fakulteten, Enheten för demografi och åldrandeforskning (CEDAR).
    Boraxbekk, Carl-Johan
    Umeå universitet, Samhällsvetenskapliga fakulteten, Enheten för demografi och åldrandeforskning (CEDAR). Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI). Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research.
    Häger, Charlotte
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi. Umeå universitet, Samhällsvetenskapliga fakulteten, Enheten för demografi och åldrandeforskning (CEDAR).
    Three dimensional kinematic analyses of finger movement control and association to brain activity responses: A pilot study on healthy individuals2017Ingår i: Gait & Posture, ISSN 0966-6362, E-ISSN 1879-2219, Vol. 57, s. 355-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Introduction: An increased knowledge of how the brain control finger movements give us keys to understand the recovery of motor function after a brain injury. This knowledge is crucial for the development of reliable and valid assessment methods in the clinical evaluation of hand function.

    Research question: How are individual finger movements represented in the brain? Investigating the associations between kinematics and brain activity responses in healthy individuals.

    Methods: Keeping the others still. Finger movements were performed lying in the MR scanner in order to register brain activity response during the task. Optoelectronic cameras simultaneously monitored the positions of reflective markers affixed to each finger. The marker position data were used to calculate each finger's movement frequency (MF),  movement independence (“Individuation Index”, II), stationary ability (Stationarity Index, SI)[1][1]. fMRI data was analyzed by contrasting the finger movements against its active rest.

    Results: Preliminary analyses showed that (1) the finger movements primarily activate sensorimotor areas in the contralateral hemisphere (Fig. 1A), (2) that use of kinematic parameters in the fMRI analyses improved spatial specificity and (3) II engage a number of cortical areas, while MF engage fewer areas (Fig. 1B–D). Further analyses will further explore activations maps for each individual finger.

    Discussion: The inclusion of movement parameters in the fMRI analyses improves the specificity in the derived activation map, increasing the interpretability of the neural correlates of movement control. This advancement carries the promise for the development of better assessment methods of the recovery of function post-stroke with usability in rehabilitation practices.

  • 10.
    Grip, Helena
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Jull, Gwendolen
    Treleaven, Julia
    Head eye co-ordination and gaze stability using simultaneous measurement of eye in head and head in space movements: potential for use in subjects with a whiplash injury2009Ingår i: Journal of clinical monitoring and computing, ISSN 1387-1307, E-ISSN 1573-2614, Vol. 23, nr 1, s. 31-40Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Objective. Describe reproducibility of a measurement method to investigate deficits in eye-head co-ordination.

    Methods. Combined recordings of head and eye rotation using wireless motion sensors and electro-oculography (EOG) were used as an initial step towards a method to quantify eye-head co-ordination deficits. Head rotation to the side during gaze fixation and sequential head and eye movements were studied on 20 asymptomatic control subjects and six subjects with chronic whiplash disorders. All included whiplash subjects reported eye disturbances according to a vision symptom questionnaire.

    Results. The trial-to-trial reproducibility was moderate to high for 24 of 28 variables (Intraclass Correlation Coefficient 0.44 to 0.87). Velocity gain (ratio of eye and head velocities) was on average close to unity in both groups. Head stability was high in control subjects, while three of six whiplash subjects demonstrated head instability during eye movement. Whiplash subjects also demonstrated a decreased range of head movement during gaze fixation and lower head velocities as compared with the asymptomatics.

    Conclusions. The method of combined head and eye motion appears to give accurate, repeatable measurements. Case studies of whiplash subjects indicated deficits in head eye co-ordination. The method could be useful in further clinical research into eye and head movement in those with neck disorders.

  • 11.
    Grip, Helena
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Jull, Gwendolen
    Treleaven, Julia
    Head eye co-ordination using simultaneous measurement of eye in head and head in space movements: potential for use in subjects with a whiplash injury.2009Ingår i: Journal of clinical monitoring and computing, ISSN 1387-1307, E-ISSN 1573-2614, Vol. 23, nr 1, s. 31-40Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Objective. Describe reproducibility of a measurement method to investigate deficits in eye-head co-ordination. Methods. Combined recordings of head and eye rotation using wireless motion sensors and electro-oculography (EOG) were used as an initial step towards a method to quantify eye-head co-ordination deficits. Head rotation to the side during gaze fixation and sequential head and eye movements were studied on 20 asymptomatic control subjects and six subjects with chronic whiplash disorders. All included whiplash subjects reported eye disturbances according to a vision symptom questionnaire. Results. The trial-to-trial reproducibility was moderate to high for 24 of 28 variables (Intraclass Correlation Coefficient 0.44 to 0.87). Velocity gain (ratio of eye and head velocities) was on average close to unity in both groups. Head stability was high in control subjects, while three of six whiplash subjects demonstrated head instability during eye movement. Whiplash subjects also demonstrated a decreased range of head movement during gaze fixation and lower head velocities as compared with the asymptomatics. Conclusions. The method of combined head and eye motion appears to give accurate, repeatable measurements. Case studies of whiplash subjects indicated deficits in head eye co-ordination. The method could be useful in further clinical research into eye and head movement in those with neck disorders.

  • 12.
    Grip, Helena
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Nilsson, Kjell G
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap.
    Häger, Charlotte G.
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Avdelningen för fysioterapi.
    Lundström, Ronnie
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Öhberg, Fredrik
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Does the Femoral Head Size in Hip Arthroplasty Influence Lower Body Movements during Squats, Gait and Stair Walking?: A Clinical Pilot Study Based on Wearable Motion Sensors2019Ingår i: Sensors, ISSN 1424-8220, E-ISSN 1424-8220, Vol. 19, nr 14, artikel-id 3240Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A hip prosthesis design with larger femoral head size may improve functional outcomes compared to the conventional total hip arthroplasty (THA) design. Our aim was to compare the range of motion (RoM) in lower body joints during squats, gait and stair walking using a wearable movement analysis system based on inertial measurement units (IMUs) in three age-matched male groups: 6 males with a conventional THA (THAC), 9 with a large femoral head (LFH) design, and 8 hip- and knee-asymptomatic controls (CTRL). We hypothesized that the LFH design would allow a greater hip RoM, providing movement patterns more like CTRL, and a larger side difference in hip RoM in THAC when compared to LFH and controls. IMUs were attached to the pelvis, thighs and shanks during five trials of squats, gait, and stair ascending/descending performed at self-selected speed. THAC and LFH participants completed the Hip dysfunction and Osteoarthritis Outcome Score (HOOS). The results showed a larger hip RoM during squats in LFH compared to THAC. Side differences in LFH and THAC groups (operated vs. non-operated side) indicated that movement function was not fully recovered in either group, further corroborated by non-maximal mean HOOS scores (LFH: 83 +/- 13, THAC: 84 +/- 19 groups, vs. normal function 100). The IMU system may have the potential to enhance clinical movement evaluations as an adjunct to clinical scales.

  • 13.
    Grip, Helena
    et al.
    Biomedical Engineering & Informatics, University Hospital of Umeå, 90185 Umeå, Sweden.
    Sundelin, Gunnevi
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering.
    Gerdle, Björn
    Department of Rehabilitation Medicine, INR, Faculty of Health Sciences, Linköping, Sweden.
    Karlsson, J Stefan
    Biomedical Engineering & Informatics, University Hospital of Umeå, 90185 Umeå, Sweden.
    Cervical helical axis characteristics and its centre of rotation during active head movements: comparisons of whiplash-associated disorders, non-specific neck pain and asymptomatic individuals2008Ingår i: Journal of Biomechanics, ISSN 0021-9290, E-ISSN 1873-2380, Vol. 41, nr 13, s. 2799-2805Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The helical axis model can be used to describe translation and rotation of spine segments. The aim of this study was to investigate the cervical helical axis and its center of rotation during fast head movements (side rotation and flexion/extension) and ball catching in patients with non-specific neck pain or pain due to whiplash injury as compared with matched controls. The aim was also to investigate correlations with neck pain intensity. A finite helical axis model with a time-varying window was used. The intersection point of the axis during different movement conditions was calculated. A repeated-measures ANOVA model was used to investigate the cervical helical axis and its rotation center for consecutive levels of 15° during head movement. Irregularities in axis movement were derived using a zero-crossing approach. In addition, head, arm and upper body range of motion and velocity were observed. A general increase of axis irregularity that correlated to pain intensity was observed in the whiplash group. The rotation center was superiorly displaced in the non-specific neck pain group during side rotation, with the same tendency for the whiplash group. During ball catching, an anterior displacement (and a tendency to an inferior displacement) of the center of rotation and slower and more restricted upper body movements implied a changed movement strategy in neck pain patients, possibly as an attempt to stabilize the cervical spine during head movement.

  • 14.
    Grip, Helena
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    Sundelin, Gunnevi
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Sjukgymnastik.
    Gerdle, Björn
    Karlsson, J Stefan
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    Variations in the axis of motion during head repositioning: a comparison of subjects with whiplash-associated disorders or non-specific neck pain and healthy controls2007Ingår i: Clinical Biomechanics, ISSN 0268-0033, E-ISSN 1879-1271, Vol. 22, nr 8, s. 865-873Artikel i tidskrift (Refereegranskat)
  • 15.
    Grip, Helena
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Sundelin, Gunnevi
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Sjukgymnastik.
    Gerdle, Björn
    Karlsson, Stefan J
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Cervical helical axis characteristics and its center of rotation during active head and upper arm movements-comparisons of whiplash-associated disorders, non-specific neck pain and asymptomatic individuals.2008Ingår i: Journal of Biomechanics, ISSN 0021-9290, E-ISSN 1873-2380, Vol. 41, nr 13, s. 2799-2805Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The helical axis model can be used to describe translation and rotation of spine segments. The aim of this study was to investigate the cervical helical axis and its center of rotation during fast head movements (side rotation and flexion/extension) and ball catching in patients with non-specific neck pain or pain due to whiplash injury as compared with matched controls. The aim was also to investigate correlations with neck pain intensity. A finite helical axis model with a time-varying window was used. The intersection point of the axis during different movement conditions was calculated. A repeated-measures ANOVA model was used to investigate the cervical helical axis and its rotation center for consecutive levels of 15 degrees during head movement. Irregularities in axis movement were derived using a zero-crossing approach. In addition, head, arm and upper body range of motion and velocity were observed. A general increase of axis irregularity that correlated to pain intensity was observed in the whiplash group. The rotation center was superiorly displaced in the non-specific neck pain group during side rotation, with the same tendency for the whiplash group. During ball catching, an anterior displacement (and a tendency to an inferior displacement) of the center of rotation and slower and more restricted upper body movements implied a changed movement strategy in neck pain patients, possibly as an attempt to stabilize the cervical spine during head movement.

  • 16.
    Grip, Helena
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Tengman, Eva
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Sjukgymnastik.
    Häger, Charlotte
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Sjukgymnastik.
    Dynamic knee stability as estimated by finite helical axis methods during drop landing twenty years after anterior cruciate ligament injury2015Ingår i: Journal of Biomechanics, ISSN 0021-9290, E-ISSN 1873-2380, Vol. 48, nr 10, s. 1906-1914Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Finite helical axis (FHA) measures of the knee joint during weight-bearing tasks may capture dynamic knee stability following Anterior Cruciate Ligament (ACL) injury. The aim was to investigate dynamic knee stability during two-leg squat (TLS) and one-leg side hop (SH) in a long-term follow-up of ACL injury, and to examine correlations with knee laxity (KT-1000), osteoarthritis (OA, Kellgren–Lawrence) and knee function (Lysholm score). Participants were injured 17–28 years ago and then treated with surgery (n=33, ACLR) or physiotherapy only (n=37, ACLPT) and healthy-knee controls (n=33) were tested. Movements were registered with an optical motion capture system. We computed three FHA inclination angles, its' Anterior–Posterior (A–P) position, and an index quantifying directional changes (DI), during stepwise knee flexion intervals of ∼15°. Injured knees were less stable compared to healthy controls' and to contralateral non-injured knees, regardless of treatment: the A–P intersection was more anterior (indicating a more anterior positioning of tibia relative to femur) positively correlating with high laxity/low knee function, and during SH, the FHA was more inclined relative to the flexion–extension axis, possibly due to reduced rotational stability. During the TLS, A–P intersection was more anterior in the non-injured knee than the injured, and DI was higher, probably related to higher load on the non-injured knee. ACLR had less anterior A–P intersection than ACLPT, suggesting that surgery enhanced stability, although rotational stability may remain reduced. More anterior A–P intersection and greater inclination between the FHA and the knee flexion–extension axis best revealed reduced dynamic stability ∼23 years post-injury.

  • 17.
    Grip, Helena
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Tengman, Eva
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Sjukgymnastik.
    Häger, Charlotte
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Sjukgymnastik.
    Quantifying motor control of the knee during side hops - healthy subjects and subjects ~20 years after anterior cruciate ligament injury2012Konferensbidrag (Övrigt vetenskapligt)
  • 18.
    Grip, Helena
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Tengman, Eva
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Häger, Charlotte K
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Dynamic knee stability estimated by finite helical axis methods during functional performance approximately twenty years after anterior cruciate ligament injury2015Ingår i: Journal of Biomechanics, ISSN 0021-9290, E-ISSN 1873-2380, Vol. 48, nr 10, s. 1906-1914Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Finite helical axis (FHA) measures of the knee joint during weight-bearing tasks may capture dynamic knee stability following Anterior Cruciate Ligament (ACL) injury. The aim was to investigate dynamic knee stability during two-leg squat (TLS) and one-leg side hop (SH) in a long-term follow-up of ACL injury, and to examine correlations with knee laxity (KT-1000), osteoarthritis (OA, Kellgren-Lawrence) and knee function (Lysholm score). Participants were injured 17-28 years ago and then treated with surgery (n=33, ACL(R)) or physiotherapy only (n=37, ACL(PT)) and healthy-knee controls (n=33) were tested. Movements were registered with an optical motion capture system. We computed three FHA inclination angles, its' Anterior-Posterior (A-P) position, and an index quantifying directional changes (DI), during stepwise knee flexion intervals of similar to 15 degrees. Injured knees were less stable compared to healthy controls' and to contralateral non-injured knees, regardless of treatment: the A-P intersection was more anterior (indicating a more anterior positioning of tibia relative to femur) positively correlating with high laxity/low knee function, and during SH, the FHA was more inclined relative to the flexion-extension axis, possibly due to reduced rotational stability. During the TLS, A-P intersection was more anterior in the non-injured knee than the injured, and DI was higher, probably related to higher load on the non-injured knee. ACL(R) had less anterior A-P intersection than ACL(PT), suggesting that surgery enhanced stability, although rotational stability may remain reduced. More anterior A-P intersection and greater inclination between the FHA and the knee flexion-extension axis best revealed reduced dynamic stability similar to 23 years post-injury.

  • 19.
    Grip, Helena
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    Öhberg, Fredrik
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Wiklund, Urban
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Sterner, Ylva
    Karlsson, J Stefan
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    Gerdle, Björn
    Classification of neck movement patterns related to whiplash-associated disorders using neural networks2003Ingår i: IEEE transactions on information technology in biomedicine, ISSN 1089-7771, Vol. 7, nr 4, s. 412-418Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper presents a new method for classification of neck movement patterns related to Whiplash-associated disorders (WAD) using a resilient backpropagation neural network (BPNN). WAD are a common diagnosis after neck trauma, typically caused by rear-end car accidents. Since physical injuries seldom are found with present imaging techniques, the diagnosis can be difficult to make. The active range of the neck is often visually inspected in patients with neck pain, but this is a subjective measure, and a more objective decision support system, that gives a reliable and more detailed analysis of neck movement pattern, is needed. The objective of this study was to evaluate the predictive ability of a BPNN, using neck movement variables as input. Three-dimensional (3-D) neck movement data from 59 subjects with WAD and 56 control subjects were collected with a ProReflex system. Rotation angle and angle velocity were calculated using the instantaneous helical axis method and motion variables were extracted. A principal component analysis was performed in order to reduce data and improve the BPNN performance. BPNNs with six hidden nodes had a predictivity of 0.89, a sensitivity of 0.90 and a specificity of 0.88, which are very promising results. This shows that neck movement analysis combined with a neural network could build the basis of a decision support system for classifying suspected WAD, even though further evaluation of the method is needed.

  • 20.
    Johansson, Anna-Maria
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Grip, Helena
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Strong, Andrew
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Selling, Jonas
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Rönnqvist, Louise
    Umeå universitet, Samhällsvetenskapliga fakulteten, Institutionen för psykologi.
    Boraxbekk, Carl-Johan
    Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI). Umeå universitet, Samhällsvetenskapliga fakulteten, Demografiska databasen.
    Häger, Charlotte
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Finger movement control and associated brain activity responses post-stroke2016Ingår i: XXI ISEK Congress, 2016Konferensbidrag (Refereegranskat)
    Abstract [en]

    BACKGROUND AND AIM: Impaired finger dexterity is common after stroke, often affecting activities of daily living. Knowledge of kinematic characteristics and of underlying neurological mechanisms of such impairments is important to understand functional recovery. This study aims to investigate finger movement control and related brain activity patterns post-stroke (PS). METHODS: Data from a subsample including 9 participants PS with residual hemiparesis affecting manual dexterity (M age- 66; 3 female) and 12 able-bodied control (C) participants (M age- 65; 3 female) were analyzed. Two series of self-paced cyclic finger extension-flexion movements in random order were performed for each hand (4 series with vision, V, and 4 without vision, NV). Optoelectronic cameras monitored the 3D movement of markers affixed to the fingertips. Motion data was used to calculate each finger's individuation index (II), reflecting movement independence, each finger's Stationarity index (SI), reflecting the ability to keep the finger still while another moves [1] and Movement frequency (MF). Functional magnetic resonance imaging, with simultaneous movement recording, was used to investigate brain activity patterns in relation to the kinematic parameters. II, SI, MF and the effect of vision were analyzed for the 4th digit. RESULTS: A factorial ANOVA 2 [group] x 2 [condition] x 2 [side] x [index type] showed an effect for group (p < .0001; PS < C); condition (p < .01; NV < V); side (p < .0001; affected/non-preferred < non-affected/preferred); and index type (p < .0001; SI < II). An interaction between group and side (p < .01) showed that indices of the affected side were lower compared to the non-affected side within the PS group and compared to both sides in the C group. No significant effects were apparent for MF but significant correlations were found between the indices and MF that were restricted to the PS group alone (over all conditions- r = -0.22; p < .01; within the NV condition- r = -0.19; p < .01; within the affected side r = -0.15; p < .05; and within the SI categorization r = -0.14; p < .05). Furthermore, within NV for the non-affected hand on the SI alone (r = -0.54; p < .05). All indicate that slower movements had higher indices. DISCUSSION: The associations between slower MF and higher index values within the PS group were located to conditions with increased difficulty (NV, affected side, and SI). Thus, reducing speed may be a selected strategy to increase control of finger movements PS when the demand on motor control is high. Further, with the applied calculation of finger movement independence we were able detect group differences, side differences within the PS group, and a positive effect of vision of the hands during performance. This indicates that this calculation is a sensitive measure that could be used to study the effects of stroke and to monitor progression in motor recovery. [1] Häger-Ross & Schieber, 2000, J Neurosci 20:8542-50

  • 21.
    Johansson, Anna-Maria
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Grip, Helena
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Strong, Andrew
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Selling, Jonas
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Rönnqvist, Louise
    Umeå universitet, Samhällsvetenskapliga fakulteten, Institutionen för psykologi.
    Boraxbekk, Carl-Johan
    Umeå universitet, Samhällsvetenskapliga fakulteten, Demografiska databasen.
    Häger, Charlotte
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Three dimensional kinematic analyses of movement control of individual fingers post-stroke2015Ingår i: Gait & Posture, ISSN 0966-6362, E-ISSN 1879-2219, Vol. 42, nr Supplement 1, s. S33-S33Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Research question: Objectives of the present study are: (1) to quantify finger movements in a 3D context and (2) by this method investigate the ability to perform individualized finger movements, with and without vision of the hands, in persons with a chronic stroke diagnosis compared to able-bodied controls.

    Introduction: Increased knowledge of how fine movement control is affected by stroke is important for the understanding of recovery of function. This is crucial for the development of reliable and valid assessment methods for evaluation of rehabilitation of the upper limbs. This study is part of the MOST project (MOST-MOvement control in STroke) where both clinical tests and 3D movement assessments are performed.

    Materials and methods: At present, 18 persons post-stroke (M age = 67 years; 6 women) and 26 able-bodied controls (M age = 62 years, 11 women) have participated. The ability to perform uni-manual individualized finger movements and the effect of vison of the hands were evaluated. Participants were instructed to move a specific finger in cyclic extension–flexion movements at the metacarpophalangeal joint, keeping the rest of the finger straight and the other fingers still, at a self-paced speed during 10 s (2 test series for each hand; 8 test series in total). The task was performed seated. The wrists were extended about 10° and fixated to a wooden frame with forearm support. Reflective markers were affixed to each fingertip and movements were recorded by optoelectronic cameras. Based on the positional change of the fingers during task performance, two indices ranging from 0-1 were calculated: (1) Individuation index (II) where the independence of each finger movement is shown and where 1 indicate complete independence, (2) stationary index (SI) where 1 indicate that the finger remains still when the other fingers move [1].

    Results: Our results show that it is possible to quantify individual finger movements by use of 3D movement analysis addressing the quality of movement performance in stroke survivors: all but 3 persons post-stroke were able to perform the task. Preliminary analyses (based on a subsample constituted of 8 post-stroke and 8 controls) verify that the test discriminated between groups where participants post-stroke had lower values on II and SI as compared to the control persons, the lowest values were observed for the middle and ring fingers. Ongoing analyses will show if vision influences the outcomes.

    Discussion: A set-up has been tested where individual finger movements can be quantified in 3D, and that discriminates between persons post stroke compared to controls. This advancement carries a promise for development of better assessment methods for recovery of function post-stroke.

    Reference

    [1] C. Häger-Ross, M.H. Schieber Quantifying the independence of human finger movements: comparisons of digits, hands and movement frequencies.J Neurosci, 20 (2000), pp. 8542–8550

     

     

  • 22.
    Johansson, Gudrun
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Frykberg, G.
    Grip, Helena
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Häger, Charlotte
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Sjukgymnastik.
    The Arm Posture Score with additional rotational components (APS6) applied to persons with stroke to assess arm movements during gait.2012Konferensbidrag (Övrigt vetenskapligt)
  • 23.
    Johansson, Gudrun M.
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Frykberg, Gunilla E.
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Grip, Helena
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Broström, Eva W
    Department of Women's and Children's Health, Karolinska Institutet.
    Häger, Charlotte
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Assessment of arm movements during gait in stroke: the Arm Posture Score2014Ingår i: Gait & Posture, ISSN 0966-6362, E-ISSN 1879-2219, Vol. 40, nr 4, s. 549-555Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The purpose of the study was to apply the Arm Posture Score (APS) to a stroke population, since comprehensive measures to quantify arm swing in the affected and non-affected arms during gait are lacking. A further aim was to investigate how gait speed and upper limb function estimated by clinical measures are related to the APS in the stroke group. The APS is the summarized root mean square deviation (RMSD) from normal, based on kinematics. Four arm movements (sagittal and frontal planes) as well as six arm movements (incorporating transversal plane) were included in the calculation of APS, referred to as APS4 and APS6, respectively. The study population consisted of 25 persons with stroke and 25 age- and gender-matched controls. The APS measures were significantly different between the affected and non-affected arms, as well as between the affected arm and the non-dominant arm of the controls (p≤0.001). Spasticity significantly influenced both APS measures, while speed only had a significant effect on the APS4. The APS measures correlated significantly to clinical measures of upper limb function. Both APS measures seem to be useful indices to quantify and discriminate between impaired and normal arm swing during gait after stroke. The variability of rotational arm movements needs to be studied further before considering the additional value of the APS6 over the APS4. When interpreting the APS, complementary kinematics should be taken into account, as the single value of the APS gives no information about the direction of the deviation.

  • 24.
    Johansson, Gudrun M.
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Grip, Helena
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Levin, Mindy F
    Häger, Charlotte
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    The added value of kinematic evaluation of the timed finger-to-nose test in persons post-stroke.2017Ingår i: Journal of NeuroEngineering and Rehabilitation, ISSN 1743-0003, E-ISSN 1743-0003, Vol. 14, artikel-id 11Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    BACKGROUND: Upper limb coordination in persons post-stroke may be estimated by the commonly used Finger-to-Nose Test (FNT), which is also part of the Fugl-Meyer Assessment. The total movement time (TMT) is used as a clinical outcome measure, while kinematic evaluation also enables an objective quantification of movement quality and motor performance. Our aims were to kinematically characterize FNT performance in persons post-stroke and controls and to investigate the construct validity of the test in persons with varying levels of impairment post-stroke.

    METHODS: A three-dimensional motion capture system recorded body movements during performance of the FNT in 33 persons post-stroke who had mild or moderate upper limb motor impairments (Fugl-Meyer scores of 50-62 or 32-49, respectively), and 41 non-disabled controls. TMT and kinematic variables of the hand (pointing time, peak speed, time to peak speed, number of movement units, path ratio, and pointing accuracy), elbow/shoulder joints (range of motion, interjoint coordination), and scapular/trunk movement were calculated. Our analysis focused on the pointing phase (knee to nose movement of the FNT). Independent t or Mann-Whitney U tests and effect sizes were used to analyze group differences. Sub-group analyses based on movement time and stroke severity were performed. Within the stroke group, simple and multiple linear regression were used to identify relationships between TMT to kinematic variables.

    RESULTS: The stroke group had significant slower TMT (mean difference 2.6 s, d = 1.33) than the control group, and six other kinematic variables showed significant group differences. At matched speeds, the stroke group had lower accuracy and excessive scapular and trunk movements compared to controls. Pointing time and elbow flexion during the pointing phase were most related to stroke severity. For the stroke group, the number of movement units during the pointing phase showed the strongest association with the TMT, and explained 60% of the TMT variance.

    CONCLUSIONS: The timed FNT discriminates between persons with mild and moderate upper limb impairments. However, kinematic analysis to address construct validity highlights differences in pointing movement post-stroke that are not captured in the timed FNT.

  • 25.
    Markström, Jonas
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering.
    Grip, Helena
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Schelin, Lina
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Häger, Charlotte
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering.
    Elite women athletes with superior knee function present similar dynamic knee stability, although different movement strategies, when compared to controls2018Ingår i: 23rd annual Congress of the European College of Sport Science: Sport Science at the cutting edge, Dublin, July 4-7, 2018, 2018Konferensbidrag (Refereegranskat)
  • 26.
    Markström, Jonas
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering.
    Grip, Helena
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Schelin, Lina
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Häger, Charlotte
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering.
    Similar dynamic knee stability but different movement strategies and between-leg asymmetries for hip and knee joints for ACL-reconstructed persons relative to knee-healthy controls2018Ingår i: 8th World Congress of Biomechanics, Dublin, July 8-12, 2018, 2018Konferensbidrag (Refereegranskat)
  • 27.
    Markström, Jonas
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Grip, Helena
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    Schelin, Lina
    Umeå universitet, Samhällsvetenskapliga fakulteten, Handelshögskolan vid Umeå universitet, Statistik.
    Häger, Charlotte K.
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Dynamic knee control and movement strategies in athletes and non‐athletes in side hops: implications for knee injury2019Ingår i: Scandinavian Journal of Medicine and Science in Sports, ISSN 0905-7188, E-ISSN 1600-0838, Vol. 29, nr 8, s. 1181-1189Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Athletes exposed to rapid maneuvers need a high level of dynamic knee stability and robustness, while also controlling whole body movement, to decrease the risk of non‐contact knee injury. The effects of high‐level athletic training on such measures of movement control have not, however, been thoroughly evaluated. This study investigated whether elite athletes (who regularly perform knee‐specific neuromuscular training) show greater dynamic knee robustness and/or different movement strategies than non‐athletic controls, in relation to overall knee function. Thirty‐nine women (19 athletes, 20 controls) performed standardized rebound side hops (SRSH) while a motion capture system synchronized with two force plates registered three‐dimensional trunk, hip, and knee joint angles and moments. Dynamic knee robustness was evaluated using finite helical axis (FHA) inclination angles extracted from knee rotation intervals of 10°, analyzed with independent t tests. Angle and moment curves were analyzed with inferential methods for functional data. Athletes had superior knee function (less laxity, greater hop performances, and strength) but presented similar FHA inclination angles to controls. Movement strategies during the landing phase differed; athletes presented larger (a) hip flexion angles (during 9%‐29% of the phase), (b) hip adduction moments (59%‐99%), (c) hip internal rotation moments (83%‐89%), and (d) knee flexion moments (79%‐93%). Thus, elite athletes may have a greater ability than non‐athletes to keep the knee robust while performing SRSH more efficiently through increased engagement of the hip. However, dynamic knee robustness associated with lower FHA inclination angles still show room for improvement, thus possibly decreasing knee injury risk.

  • 28.
    Markström, Jonas L.
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Grip, Helena
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    Schelin, Lina
    Umeå universitet, Samhällsvetenskapliga fakulteten, Handelshögskolan vid Umeå universitet, Statistik.
    Häger, Charlotte K.
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Individuals with anterior cruciate ligament reconstruction adopt different movement strategies but display robust knees during side hop landingsManuskript (preprint) (Övrigt vetenskapligt)
  • 29.
    Markström, Jonas L.
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Tengman, Eva
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Grip, Helena
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    Schelin, Lina
    Umeå universitet, Samhällsvetenskapliga fakulteten, Handelshögskolan vid Umeå universitet, Statistik.
    Häger, Charlotte K.
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    A comparison of knee joint kinematics and kinetics during landings in three one-leg hop tests (hop for distance, vertical hop and side hop) performed by female elite floorball athletes2016Ingår i: XXI ISEK Congress: Bridges to Innovation, 2016Konferensbidrag (Refereegranskat)
  • 30.
    Röijezon, Ulrik
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi. Centre for Musculoskeletal Research, University of Gävle, Sweden; Alfta Research Foundation, Alfta, Sweden .
    Djupsjöbacka, Mats
    Centre for Musculoskeletal Research, University of Gävle, Sweden.
    Björklund, Martin
    Centre for Musculoskeletal Research, University of Gävle, Sweden; Alfta Research Foundation, Alfta, Sweden.
    Häger Ross, Charlotte
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Grip, Helena
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF). Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Liebermann, Dario
    Sackler Faculty of Medicine, Tel Aviv University, Israel.
    Kinematics of fast cervical rotations in persons with chronic neck pain: a cross-sectional and reliability study2010Ingår i: BMC Musculoskeletal Disorders, ISSN 1471-2474, E-ISSN 1471-2474, Vol. 11, s. 222-Artikel i tidskrift (Övrigt vetenskapligt)
    Abstract [en]

    Background

    Assessment of sensorimotor function is useful for classification and treatment evaluation of neck pain disorders. Several studies have investigated various aspects of cervical motor functions. Most of these have involved slow or self-paced movements, while few have investigated fast cervical movements. Moreover, the reliability of assessment of fast cervical axial rotation has, to our knowledge, not been evaluated before.

    Methods

    Cervical kinematics was assessed during fast axial head rotations in 118 women with chronic nonspecific neck pain (NS) and compared to 49 healthy controls (CON). The relationship between cervical kinematics and symptoms, self-rated functioning and fear of movement was evaluated in the NS group. A sub-sample of 16 NS and 16 CON was re-tested after one week to assess the reliability of kinematic variables. Six cervical kinematic variables were calculated: peak speed, range of movement, conjunct movements and three variables related to the shape of the speed profile.

    Results

    Together, peak speed and conjunct movements had a sensitivity of 76% and a specificity of 78% in discriminating between NS and CON, of which the major part could be attributed to peak speed (NS: 226 ± 88 °/s and CON: 348 ± 92 °/s, p < 0.01). Peak speed was slower in NS compared to healthy controls and even slower in NS with comorbidity of low-back pain. Associations were found between reduced peak speed and self-rated difficulties with running, performing head movements, car driving, sleeping and pain. Peak speed showed reasonably high reliability, while the reliability for conjunct movements was poor.

    Conclusions

    Peak speed of fast cervical axial rotations is reduced in people with chronic neck pain, and even further reduced in subjects with concomitant low back pain. Fast cervical rotation test seems to be a reliable and valid tool for assessment of neck pain disorders on group level, while a rather large between subject variation and overlap between groups calls for caution in the interpretation of individual assessments.

  • 31.
    Sandlund, Marlene
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Sjukgymnastik.
    Domellöf, Erik
    Umeå universitet, Samhällsvetenskapliga fakulteten, Institutionen för psykologi.
    Grip, Helena
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Sjukgymnastik.
    Rönnqvist, Louise
    Umeå universitet, Samhällsvetenskapliga fakulteten, Institutionen för psykologi.
    Häger, Charlotte
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Sjukgymnastik.
    Effect of practice with motion interactive video games on goal-directed arm movements in children with cerebral palsy: a kinematic evaluationManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Objective: The aim of the present study was to evaluate the quality of goal-directed arm movements in children with cerebral palsy after four weeks of daily practice with motion interactive games, and to explore and compare the applicability of various kinematic parameters in a virtual context compared to a situation with real objects.

    Methods: Fifteen children with CP, 6-16 years, practiced with the EyeToyâ for PlayStation2â in their homes during four weeks. Before and after the intervention kinematics and kinetics were captured with a five camera motion analysis system (Proreflex, Qualisys AB, Gothenburg, Sweden) and a force plate. The children performed arm movements towards both virtual and real targets.

    Results: The children used a more economic reaching strategy with shorter Centre of pressure paths, improved Movement precision, and reduced variability in Maximal shoulder angles during play after practice. Transfer of improved motor control to goal-directed arm movements towards real targets was also indicated by increased Movement smoothness, and while reaching with the non-dominant side, reduced Centre of pressure paths path. The spatiotemporal characteristics proved complex to interpret in terms of improved motor control.

    Conclusions: When taking the constraints of the tasks into account the relevant kinematic parameters explored support the conclusion that practice with motion interactive games resulted in an improved motor control. The results of this study illuminate the importance of considering both the nature of the task and the context in which movements are performed when selecting and interpreting kinematic parameters.

  • 32.
    Sandlund, Marlene
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Sjukgymnastik.
    Domellöf, Erik
    Umeå universitet, Samhällsvetenskapliga fakulteten, Institutionen för psykologi.
    Grip, Helena
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Sjukgymnastik.
    Rönnqvist, Louise
    Umeå universitet, Samhällsvetenskapliga fakulteten, Institutionen för psykologi.
    Häger, Charlotte K.
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Training of goal directed arm movements with motion interactive video games in children with cerebral palsy: a kinematic evaluation2014Ingår i: Developmental Neurorehabilitation, ISSN 1751-8423, E-ISSN 1751-8431, Vol. 17, nr 5, s. 318-326Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Objective: The main aim of this study was to evaluate the quality of goal-directed arm movements in 15 children with cerebral palsy (CP) following four weeks of home-based training with motion interactive video games. A further aim was to investigate the applicability and characteristics of kinematic parameters in a virtual context in comparison to a physical context.

    Method: Kinematics and kinetics were captured while the children performed arm movements directed towards both virtual and physical targets.

    Results: The children’s movement precision improved, their centre of pressure paths decreased, as did the variability in maximal shoulder angles when reaching for virtual objects. Transfer to a situation with physical targets was mainly indicated by increased movement smoothness.

    Conclusion: Training with motion interactive games seems to improve arm motor control in children with CP. The results highlight the importance of considering both the context and the task itself when investigating kinematic parameters.

  • 33.
    Sandlund, Marlene
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Sjukgymnastik.
    Grip, Helena
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Sjukgymnastik.
    Häger, Charlotte
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Sjukgymnastik.
    Domellöf, Erik
    Umeå universitet, Samhällsvetenskapliga fakulteten, Institutionen för psykologi.
    Rönnqvist, Louise
    Umeå universitet, Samhällsvetenskapliga fakulteten, Institutionen för psykologi.
    Low-cost motion interactive video games in home training for children with cerebral palsy: A kinematic evaluation2011Ingår i: 2011 International Conference on Virtual Rehabilitation, ICVR / [ed] Daniel Thalmann, IEEE conference proceedings, 2011Konferensbidrag (Refereegranskat)
    Abstract [en]

    3D motion analysis was applied to assess goal-directed arm movements in 15 children with cerebral palsy (CP) before and after four weeks of home training with low-cost motion interactive video games. The results indicated that the children improved movement precision when playing the virtual games, improved movement smoothness when reaching for real targets, and reduced the involvement of the trunk especially when reaching with the non-dominant side. © 2011 IEEE.

  • 34. Sole, Gisela
    et al.
    Tengman, Eva
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Sjukgymnastik.
    Grip, Helena
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Häger, Charlotte
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Sjukgymnastik.
    Knee kinematics during stair descent 20 years following anterior cruciate ligament rupture with and without reconstruction2016Ingår i: Clinical Biomechanics, ISSN 0268-0033, E-ISSN 1879-1271, Vol. 32, s. 180-186Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Changes and asymmetries for walking gait have been explored extensively following injuries of anterior cruciate ligaments within ten years of injury or reconstruction. We examined longer term knee joint kinematics of reconstructed and non-reconstructed knees during stair descent compared to controls. Methods: Three-dimensional knee kinematics during stair descent were registered for 33 subjects with ACL reconstruction, 36 subjects with ACL rupture managed with physiotherapy only and 31 uninjured controls. Injured subjects were 23.5 (2.1) years following injury. Linear mixed models were used to compare temporal variables and knee kinematics during stance phase between groups and contralateral sides. Findings: Walking speed was slower for the both ACL-injured groups compared to controls and stance duration was longer for the injured than the uninjured sides of the physiotherapy-only group. Compared to controls, the physiotherapy-only group had significantly less adduction at initial foot contact of the injured and uninjured knees. The uninjured side of the physiotherapy-only group also had less flexion than controls at initial foot contact and during weight acceptance. Compared to the surgically-managed group, the injured sides of the physiotherapy-only groups had significantly less adduction at initial contact, peak adduction during weight acceptance, and peak flexion during propulsion. Interpretation: Independent of treatment, altered knee kinematics exist more than 20 years following ACL injury during stair descent. We suggest that future studies investigating short and long-term kinematic outcomes of ACL injury could evaluate stair descent with particular emphasis on weight acceptance of stance, and potential associations to perceived knee function.

  • 35.
    Stensdotter, Ann Katrin
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Sjukgymnastik.
    Grip, Helena
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    Hodges, P
    Häger Ross, Charlotte
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Sjukgymnastik.
    Quadriceps activity and movement in response to unpredictable sagital support-surface translations2007Konferensbidrag (Övrigt vetenskapligt)
  • 36.
    Stensdotter, Ann Katrin
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Sjukgymnastik.
    Grip, Helena
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Hodges, P W
    Häger-Ross, Charlotte
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Sjukgymnastik.
    Quadriceps activity and movement reactions in response to unpredictable sagittal support-surface translations in women with patellofemoral pain.2008Ingår i: Journal of Electromyography & Kinesiology, ISSN 1050-6411, E-ISSN 1873-5711, Vol. 18, nr 2, s. 298-307Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Patellofemoral pain (PFP) may be related to unfavorable knee joint loading. Delayed and/or reduced activity of vastus medialis obliquus (VMO) and different movement patterns have been identified in individuals with PFP in some studies, whereas other studies have failed to show a difference compared to non-affected controls. The discrepancy between study results may depend on the different tasks that have been investigated. No previous study has investigated these variables in postural responses to unpredictable perturbations in PFP. Whole body three dimensional kinematics and surface EMG of quadriceps muscles activation was studied in postural responses to unpredictable support surface translations in 17 women with PFP who were pain free at the time of testing, and 17 matched healthy controls. The results of the present study showed earlier onset of VMO activity and associated changes in kinematics to anterior platform translation in the PFP subjects. We suggest that the relative timing between the portions quadriceps muscles may be task specific and part of an adapted response in attempt to reduce knee joint loading. This learned response appears to remain even when the pain is no longer present.

  • 37.
    Tengman, Eva
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Sjukgymnastik.
    Grip, Helena
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Häger, Charlotte
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Sjukgymnastik.
    Motor control aspects in the understanding of knee disorders – implications for rehabilitation2014Konferensbidrag (Övrigt vetenskapligt)
  • 38.
    Tengman, Eva
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Sjukgymnastik.
    Grip, Helena
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Häger, Charlotte
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Sjukgymnastik.
    One-leg hop – kinematic analysis ~ 20 years after anterior cruciate ligament injury.2012Konferensbidrag (Övrigt vetenskapligt)
  • 39.
    Tengman, Eva
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Sjukgymnastik.
    Grip, Helena
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Sjukgymnastik.
    Stensdotter, A.
    Häger, Charlotte
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Sjukgymnastik.
    Kinematic analysis of one-leg hop more than 20 years after anterior cruciate ligament injury2014Ingår i: Knee Surgery, Sports Traumatology, Arthroscopy, Springer, 2014, Vol. 22, s. S291-S291, artikel-id P15-2121Konferensbidrag (Refereegranskat)
  • 40.
    Tengman, Eva
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Sjukgymnastik.
    Grip, Helena
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Sjukgymnastik.
    Stensdotter, Ann-Katrin
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Sjukgymnastik. Sør-Trøndelag University College, Trondheim Norway.
    Häger, Charlotte
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Sjukgymnastik.
    One-leg hop more than 20 years after ACL injury: kinematic analysis of persons treated with physiotherapy with or without surgery compared to healthy controlsManuskript (preprint) (Övrigt vetenskapligt)
  • 41.
    Tengman, Eva
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Grip, Helena
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Stensdotter, Ann-Katrin
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi. Faculty of Health Education and Social Work, Physiotherapy, Sør-Trøndelag University College, Trondheim, Norway.
    Häger, Charlotte K
    Anterior cruciate ligament injury about 20 years post-treatment: a kinematic analysis of one-leg hop2015Ingår i: Scandinavian Journal of Medicine and Science in Sports, ISSN 0905-7188, E-ISSN 1600-0838, Vol. 25, nr 6, s. 818-827Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Reduced dynamic knee stability, often evaluated with one-leg hops (OLHs), is reported after anterior cruciate ligament (ACL) injury. This may lead to long-standing altered movement patterns, which are less investigated. 3D kinematics during OLH were explored in 70 persons 23 +/- 2 years after ACL injury; 33 were treated with physiotherapy in combination with ACL reconstruction (ACL(R)) and 37 with physiotherapy alone (ACL(PT)). Comparisons were made to 33 matched controls. We analyzed (a) maximal knee joint angles and range of motion (flexion, abduction, rotation); (b) medio-lateral position of the center of mass (COM) in relation to knee and ankle joint centers, during take-off and landing phases. Unlike controls, ACL-injured displayed leg asymmetries: less knee flexion and less internal rotation at take-off and landing and more lateral COM related to knee and ankle joint of the injured leg at landing. Compared to controls, ACL(R) had larger external rotation of the injured leg at landing. ACL(PT) showed less knee flexion and larger external rotation at take-off and landing, and larger knee abduction at Landing. COM was more medial in relation to the knee at take-off and less laterally placed relative to the ankle at landing. ACL injury results in long-term kinematic alterations during OLH, which are less evident for ACL(R).

  • 42. Treleaven, Julia
    et al.
    Takasaki, Hiro
    Grip, Helena
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Altered trunk head co-ordination in those with persistent neck pain2019Ingår i: Musculoskeletal Science and Practice, ISSN 2468-7812, Vol. 39, s. 45-50Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Decreased neck motion and sensorimotor deficits have been identified in those with neck pain. It is thought that these might be related to altered reflex mechanisms between the neck, eyes and the vestibular system. Trunk, head co-ordination might also be altered in neck pain.

    Objectives: This study investigated trunk head co-ordination ability in subjects with neck pain compared to asymptomatic controls.

    Method: Twenty-four subjects with persistent neck pain and twenty-six age and gender matched healthy controls performed 3 trials of 3 trunk movements whilst trying to keep the head still - (1) alternate trunk movement to the left and right (2) trunk movement to the left (3) trunk movement to the right. Wireless motion sensors positioned over the sternum and the forehead measured trunk and head range and velocity of motion.

    Analysis: ANOVA was used to compare trunk and head range and velocity of motion during the 3 tasks.

    Results: Neck pain subjects had significantly less trunk movement (p < 0.05) and velocity (p = < 0.02) as well as significantly increased head movement (p = < 0.03) during most tasks compared to control subjects.

    Discussion: The results of the study suggest that neck pain subjects have difficulty moving their trunk independently of their head. They are less able to keep the head still while moving the trunk and perform the tasks more slowly. These findings might be related to altered reflex activity of the cervico-collic reflex and sensorimotor control. Further research is required.

  • 43. Öhberg, F
    et al.
    Grip, Helena
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Nilsson, K-G
    Edström, U
    Gustavsson, O
    Häger, Charlotte
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Sjukgymnastik.
    Lundström, R
    Gait analysis using a portable motion sensor system: measurements in subjects with hip implants as compared with healthy controls2012Konferensbidrag (Övrigt vetenskapligt)
  • 44.
    Öhberg, Fredrik
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    Bäcklund, Tomas
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Sundström, Nina
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    Grip, Helena
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    Portable Sensors Add Reliable Kinematic Measures to the Assessment of Upper Extremity Function2019Ingår i: Sensors, ISSN 1424-8220, E-ISSN 1424-8220, Vol. 19, nr 5, artikel-id 1241Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Ordinal scales with low resolution are used to assess arm function in clinic. These scales may be improved by adding objective kinematic measures. The aim was to analyze within-subject, inter-rater and overall reliability (i.e., including within-subject and inter-rater reliability) and check the system's validity of kinematic measures from inertial sensors for two such protocols on one person. Twenty healthy volunteers repeatedly performed two tasks, finger-to-nose and drinking, during two test sessions with two different raters. Five inertial sensors, on the forearms, upper arms and xiphoid process were used. Comparisons against an optical camera system evaluated the measurement validity. Cycle time, range of motion (ROM) in shoulder and elbow were calculated. Bland-Altman plots and linear mixed models including the generalizability (G) coefficient evaluated the reliability of the measures. Within-subject reliability was good to excellent in both tests (G = 0.80-0.97) and may serve as a baseline when assessing upper extremities in future patient groups. Overall reliability was acceptable to excellent (G = 0.77-0.94) for all parameters except elbow axial rotation in finger-to-nose task and both elbow axial rotation and flexion/extension in drinking task, mainly due to poor inter-rater reliability in these parameters. The low to good reliability for elbow ROM probably relates to high within-subject variability. The sensors provided good to excellent measures of cycle time and shoulder ROM in non-disabled individuals and thus have the potential to improve today's assessment of arm function.

  • 45.
    Öhberg, Fredrik
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Grip, Helena
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    Wiklund, Urban
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Sterner, Ylva
    Karlsson, J Stefan
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    Gerdle, Björn
    Chronic whiplash associated disorders and neck movement measurements: an instantaneous helical axis approach.2003Ingår i: IEEE transactions on information technology in biomedicine, ISSN 1089-7771, E-ISSN 1558-0032, Vol. 7, nr 4, s. 274-282Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper presents an assessment tool for objective neck movement analysis of subjects suffering from chronic whiplash-associated disorders (WAD). Three-dimensional (3-D) motion data is collected by a commercially available motion analysis system. Head rotation, defined in this paper as the rotation angle around the instantaneous helical axis (IHA), is used for extracting a number of variables (e.g., angular velocity and range, symmetry of motion). Statistically significant differences were found between controls and subjects with chronic WAD in a number of variables.

  • 46.
    Öhberg, Fredrik
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Lundström, Ronnie
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF). Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Yrkes- och miljömedicin.
    Grip, Helena
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Comparative analysis of different adaptive filters for tracking lower segments of a human body using inertial motion sensors2013Ingår i: Measurement science and technology, ISSN 0957-0233, E-ISSN 1361-6501, Vol. 24, nr 8, s. 085703-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    For all segments and tests, a modified Kalman filter and a quasi-static sensor fusion algorithm were equally accurate (precision and accuracy similar to 2-3 degrees) compared to normalized least mean squares filtering, recursive least-squares filtering and standard Kalman filtering. The aims were to: (1) compare adaptive filtering techniques used for sensor fusion and (2) evaluate the precision and accuracy for a chosen adaptive filter. Motion sensors (based on inertial measurement units) are limited by accumulative integration errors arising from sensor bias. This drift can partly be handled with adaptive filtering techniques. To advance the measurement technique in this area, a new modified Kalman filter is developed. Differences in accuracy were observed during different tests especially drift in the internal/external rotation angle. This drift can be minimized if the sensors include magnetometers.

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