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Zafar, Hamayun
Publications (10 of 29) Show all publications
Zafar, H., Alghadir, A. H. & Iqbal, Z. A. (2019). Effect of jaw functional status on neck muscle endurance. Archives of Oral Biology, 101, 30-33
Open this publication in new window or tab >>Effect of jaw functional status on neck muscle endurance
2019 (English)In: Archives of Oral Biology, ISSN 0003-9969, E-ISSN 1879-1506, Vol. 101, p. 30-33Article in journal (Refereed) Published
Abstract [en]

Objective: To investigate the effect of resting jaw and maximum voluntary clenching on neck flexor and extensor muscle endurance.

Design: Neck flexor and extensor endurance was measured in a college health clinic in 85 male college students in two test positions: resting jaw (control) and maximum voluntary clenching.

Results: Mean neck flexor muscle endurance values during resting jaw and maximum voluntary clenching were 70.06 SD 28.24, and 60.03 SD 16.5, seconds respectively. Mean neck extensor muscle endurance values during resting jaw and maximum voluntary clenching were 105.54 SD 29.9, and 98.32 SD 24.54, respectively. Both values were significantly lower while maximum voluntary clenching as compared to resting jaw position (p < 0.05).

Conclusion: Modification of jaw position can affect neck muscle endurance. Results of this study further supports sensory-motor relation between jaw and neck region.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Neck, Endurance, Jaw position, Maximum voluntary clenching
National Category
Dentistry
Identifiers
urn:nbn:se:umu:diva-159396 (URN)10.1016/j.archoralbio.2019.03.001 (DOI)000466252300005 ()30875591 (PubMedID)
Available from: 2019-06-10 Created: 2019-06-10 Last updated: 2019-06-10Bibliographically approved
Alghadir, A. H., Zafar, H., Iqbal, Z. A. & Al-Eisa, E. S. (2019). Effect of voluntary teeth clenching and sitting posture on maximal static force of limb muscles. Journal of Sports Medicine and Physical Fitness, 59(5), 774-778
Open this publication in new window or tab >>Effect of voluntary teeth clenching and sitting posture on maximal static force of limb muscles
2019 (English)In: Journal of Sports Medicine and Physical Fitness, ISSN 0022-4707, E-ISSN 1827-1928, Vol. 59, no 5, p. 774-778Article in journal (Refereed) Published
Abstract [en]

BACKGROUND: People clench their teeth to activate facial, neck and abdominal muscles when they need to generate heavy muscle force against large resistance like lifting heavy objects, in order to gain possible ergogenic advantage. These are termed as remote voluntary contractions. Aim of this study was to evaluate the effect of voluntary teeth clenching on maximal voluntary contraction of extensors and flexors of the knee, shoulder and elbow joints of the dominant side during slouch and unsupported upright sitting.

METHODS: One hundred healthy young male adults (mean age 23.3 years) participated in this study. Maximal voluntary contraction was measured using a hand-held dynamometer.

RESULTS: Jaw clenching caused different ergogenic effect during slouch versus unsupported sitting postures. The data revealed that during unsupported upright sitting, the effect of jaw clenching consistently results in larger maximal voluntary contraction of both extensor and flexor muscles of all the three studied joints. However, during slouch sitting, only the maximal voluntary contraction of extensors of elbow and flexors of knee were larger with clenched teeth position.

CONCLUSIONS: Jaw clenching can affect the maximal voluntary contraction of limb muscles which is sitting posture dependent. Jaw clenching can consistently facilitate certain muscles of the upper and lower limbs to generate greater force production during upright sitting.

Place, publisher, year, edition, pages
Turin: Edizioni Minerva Medica, 2019
Keywords
Posture, Jaw, Muscles
National Category
Physiotherapy
Identifiers
urn:nbn:se:umu:diva-158721 (URN)10.23736/S0022-4707.18.08341-X (DOI)000463024800007 ()29619804 (PubMedID)
Available from: 2019-05-21 Created: 2019-05-21 Last updated: 2019-05-21Bibliographically approved
Eriksson, P.-O., Zafar, H. & Backén, M. (2019). Instant reduction in postural sway during quiet standing by intraoral dental appliance in patients with Whiplash associated Disorders and non-trauma neck pain. Archives of Oral Biology, 97, 109-115
Open this publication in new window or tab >>Instant reduction in postural sway during quiet standing by intraoral dental appliance in patients with Whiplash associated Disorders and non-trauma neck pain
2019 (English)In: Archives of Oral Biology, ISSN 0003-9969, E-ISSN 1879-1506, Vol. 97, p. 109-115Article in journal (Refereed) Published
Abstract [en]

Objectives: This study tested the hypothesis that modulation of jaw sensorimotor control by intraoral dental appliance can reduce postural sway during quiet standing and hence improve standing balance, in patients with whiplash associated disorders (WAD) and non-trauma neck pain. Design: Postural sway during quiet standing with feet together was examined in 54 WAD patients (40 females) and 10 non-trauma patients (8 females) using wireless 3D movement recording technique. Recordings were performed alternating without and with intraoral dental appliance, and with closed eyes and open eyes, respectively. In this protocol the participants served as their own controls. A reference group of 30 healthy subjects (17 females) was also recorded. Each recording lasted 120 s, followed by 3-5 min of rest. Speed, acceleration and perimeter of postural sway area were documented. Results: In the patients, but not in the healthy group, the intraoral dental appliance instantly and significantly reduced standing postural sway in recordings with closed and open eyes. Conclusions: The prompt reduction in standing postural sway from intervention by intraoral dental appliance i.e. improved standing balance, suggests a potent effect on the postural control system by modulation of the jaw sensorimotor system, probably involving reflex transmission. The result opens for new insight into mechanisms behind postural control and the pathophysiology of balance disorders, and adds to the knowledge on plasticity of the nervous system. It may help developing new procedures for assessment and management of impaired balance in WAD and non-trauma neck pain patients.

Place, publisher, year, edition, pages
PERGAMON-ELSEVIER SCIENCE LTD, 2019
Keywords
Balance, Postural sway, Intraoral dental appliance, Jaw, Neck, Non-trauma neck pain, Pain, Postural ntrol, Whiplash associated disorders, WAD
National Category
Dentistry
Identifiers
urn:nbn:se:umu:diva-154328 (URN)10.1016/j.archoralbio.2018.10.018 (DOI)000451492700016 ()30384151 (PubMedID)
Available from: 2018-12-18 Created: 2018-12-18 Last updated: 2018-12-18Bibliographically approved
Alghadir, A. H., Anwer, S., Zafar, H. & Iqbal, Z. A. (2018). Effect of localised vibration on muscle strength in healthy adults: a systematic review. Physiotherapy, 104(1), 18-24
Open this publication in new window or tab >>Effect of localised vibration on muscle strength in healthy adults: a systematic review
2018 (English)In: Physiotherapy, ISSN 0031-9406, E-ISSN 1873-1465, Vol. 104, no 1, p. 18-24Article, review/survey (Refereed) Published
Abstract [en]

Objective To investigate the effects of local vibration on muscle strength in healthy adults.

Data sources The electronic databases PubMed, CINAHL, Scopus and Web of Science were searched using a combination of the following keywords: vibration, vibration therapy, power, maximal voluntary contraction, performance, rate of force development and vibratory exercise. In addition, the Medical Subject Headings 'vibration', 'strength' and 'exercise' were used. The bibliographical search was limited to articles published in English.

Study selection Trials that evaluated the effect of localised vibration on muscle strength in healthy humans were included.

Data extraction Two independent evaluators verified the quality of the selected studies using the PEDro Scale and the Cochrane Collaboration's tool for assessing the risk of bias. Muscle strength was calculated for each intervention.

Results In total, 29 full-text studies were assessed for eligibility. Eighteen studies did not match the inclusion criteria, and were excluded. The 11 studies included in this review had an average PEDro score of 5.36/10. Most of the studies reported significant improvements in muscle strength after the application of local vibration. There was considerable variation in the vibration training parameters and target muscle location.

Conclusions The use of local vibration on the target muscle can enhance muscle strength in healthy adults. Further well-designed controlled studies are required to confirm the effect of local vibration training on muscle strength. 

Place, publisher, year, edition, pages
Elsevier, 2018
Keywords
Vibration training, Local vibration, Strength training, Muscle strength
National Category
Physiotherapy
Identifiers
urn:nbn:se:umu:diva-146582 (URN)10.1016/j.physio.2017.06.006 (DOI)000426458600004 ()28947078 (PubMedID)
Available from: 2018-05-07 Created: 2018-05-07 Last updated: 2018-06-09Bibliographically approved
Omar, M. T. A., Alghadir, A. H., Zafar, H. & Al Baker, S. (2018). Hand grip strength and dexterity function in children aged 6-12 years: a cross-sectional study. Journal of Hand Therapy, 31(1), 93-101
Open this publication in new window or tab >>Hand grip strength and dexterity function in children aged 6-12 years: a cross-sectional study
2018 (English)In: Journal of Hand Therapy, ISSN 0894-1130, E-ISSN 1545-004X, Vol. 31, no 1, p. 93-101Article in journal (Refereed) Published
Abstract [en]

Study Design: Cross-sectional and clinical measurement. Introduction: Assessment of hand function considers an essential part in clinical practice. Purpose of the Study: To develop normative values of hand grip strength and dexterity function for 6-12 year -old children in Saudi Arabia. Methods: Grip strength and dexterity function was measured in 525 children using Grip Track hand dynamometer (JTECH Medical, Midvale, UT, USA) and 9-hole pegboard test respectively. Results: The grip strength and dexterity function was improved as age progressed regardless of gender. Across all age groups, the hand grip strength of boys was significantly higher than girls for dominant hand (31.75 +/- 10.33 vs 28.24 +/- 9.35; P < .001) and nondominant hand (31,01 +/- 10.27 vs 27.27 +/- 9.30; P < .001). The girls performed slightly faster than boys for dominant hand (19.70 vs 20.68; P < .05) and nondominant hand (21.79 vs 23.46; P < .05). In general, girls completed a 9-HPT faster than boys in the 2 of 7 age groups: 11 years (9-HPT scores = 2.10 seconds; P < .01) and 12 years (9-HPT scores = 1.93 seconds; P < .01). Discussion: The overall patterns of hand grip strength and dexterity function observed in the present study are similar to the previous studies that established acceleration of grip strength with advanced age, and faster performance scores in older children than younger children in both genders. Conclusions: Norms of hand grip strength and dexterity enable therapists to identify some developmental characteristics of hand function among Saudi children, determine the presence of impairment, and compare scores from children in different clinical settings.

Place, publisher, year, edition, pages
HANLEY & BELFUS-ELSEVIER INC, 2018
Keywords
Hand strength, Dexterity function, Children
National Category
Occupational Therapy
Identifiers
urn:nbn:se:umu:diva-145802 (URN)10.1016/j.jht.2017.02.004 (DOI)000426227500014 ()28343852 (PubMedID)
Available from: 2018-03-22 Created: 2018-03-22 Last updated: 2018-06-09Bibliographically approved
Almosa, N. & Zafar, H. (2018). Incidence of orthodontic brackets detachment during orthodontic treatment: A systematic review. Pakistan journal of medical sciences print, 34(3), 744-750
Open this publication in new window or tab >>Incidence of orthodontic brackets detachment during orthodontic treatment: A systematic review
2018 (English)In: Pakistan journal of medical sciences print, ISSN 1682-024X, E-ISSN 1681-715X, Vol. 34, no 3, p. 744-750Article, review/survey (Refereed) Published
Abstract [en]

Objectives: To evaluate the incidence of orthodontic brackets detachment during orthodontic treatment.

Methods: Using electronic databases; eligible studies up to January 2018 were retrieved, independently reviewed, and screened. The Coleman Methodology Scoring System (CMS) and Cochrane Collaboration's tool were used to assess quality and risk of bias in the included studies.

Results: Of the seventeen studies included in the final synthesis, thirteen were categorized as randomized clinical trials (RCTs), one prospective cohort and retrospective survey each, whereas two studies could not be categorized. The number of patients in the selected studies ranged between 19 and 153; the mean age was between 10.5 to 38.7 years, and male to female ratio was 353:495. Almost all studies had a high risk of bias, and more than half of the studies had CMS score of 70 or above. The numbers of brackets examined in the studies ranged between 361 and 3336. The incidence of brackets detachment ranged from 0.6 to 28.3%.

Conclusions: The incidence of brackets detachment during orthodontic treatment is high.

Place, publisher, year, edition, pages
Professional Medical Publications, 2018
Keywords
Orthodontic treatment, Brackets detachment, Bracket de-bonding, Bracket failure, Prevalence, Incidence
National Category
Dentistry
Identifiers
urn:nbn:se:umu:diva-150396 (URN)10.12669/pjms.343.15012 (DOI)000439016200043 ()30034451 (PubMedID)2-s2.0-85049128922 (Scopus ID)
Available from: 2018-08-06 Created: 2018-08-06 Last updated: 2018-08-06Bibliographically approved
Zafar, H., Alghadir, A. H. & Iqbal, Z. A. (2017). Effect of different head-neck-jaw postures on cervicocephalic kinesthetic sense. Journal of Musculoskeletal and Neuronal Interactions - JMNI, 17(4), 341-346
Open this publication in new window or tab >>Effect of different head-neck-jaw postures on cervicocephalic kinesthetic sense
2017 (English)In: Journal of Musculoskeletal and Neuronal Interactions - JMNI, ISSN 1108-7161, Vol. 17, no 4, p. 341-346Article in journal (Refereed) Published
Abstract [en]

Objectives: To investigate the effect of different induced head-neck-jaw postures on head-neck relocation error among healthy subjects.

Methods: 30 healthy adult male subjects participated in this study. Cervicocephalic kinesthetic sense was measured while standing, habitual sitting, habitual sitting with clenched jaw and habitual sitting with forward head posture during right rotation, left rotation, flexion and extension using kinesthetic sensibility test.

Results: Head-neck relocation error was least while standing, followed by habitual sitting, habitual sitting with forward head posture and habitual sitting with jaw clenched. However, there was no significant difference in error between different tested postures during all the movements.

Conclusions: To the best of our knowledge, this is the first study to see the effect of different induced head-neck-jaw postures on head-neck position sense among healthy subjects. Assuming a posture for a short duration of time doesn’t affect head-neck relocation error in normal healthy subjects.

Keywords
Cervicocephalic Kinesthetic Sense, Posture, Clenched Jaw, Forward Head Posture
National Category
Occupational Health and Environmental Health
Identifiers
urn:nbn:se:umu:diva-144120 (URN)000418900100014 ()29199196 (PubMedID)
Available from: 2018-01-25 Created: 2018-01-25 Last updated: 2018-06-09Bibliographically approved
Alghadir, A. H., Anwer, S., Zafar, H. & Al-Eisa, E. S. (2017). Effect of quadriceps and hamstrings muscle cooling on standing balance in healthy young men. Journal of Musculoskeletal and Neuronal Interactions - JMNI, 17(3), 176-182
Open this publication in new window or tab >>Effect of quadriceps and hamstrings muscle cooling on standing balance in healthy young men
2017 (English)In: Journal of Musculoskeletal and Neuronal Interactions - JMNI, ISSN 1108-7161, Vol. 17, no 3, p. 176-182Article in journal (Refereed) Published
Abstract [en]

Objective: The present study compared the effect of quadriceps and hamstring muscle cooling on standing balance in healthy young men.

Methods: Thirty healthy young men (18-30 years) participated in the study. The participants were randomly assigned to three groups (n=10 each): quadriceps cooling (QC), hamstring cooling (HC), or control group (no cooling). Participants in the QC and HC groups received 20 minutes of cooling using a cold pack (gel pack), placed on the anterior thigh (from the apex of the patella to the mid-thigh) and the posterior thigh (from the base of the popliteal fossa to the mid-thigh), respectively. Balance score including unilateral stance was measured at baseline and immediately after the application of the cold pack.

Results: No significant difference in the balance score was noted in any group after the application of the cold pack (p>0.05). Similarly, no significant differences in post-test balance score were noted among the three groups (p>0.05).

Conclusions: Cooling of the quadriceps and hamstring muscles has no immediate effect on standing balance in healthy young men. However, longitudinal studies are warranted to investigate the long-term effects of cooling these muscles on standing balance.

Place, publisher, year, edition, pages
JMNI, 2017
Keywords
Cooling Effect, Balance, Ice, Men
National Category
Physiotherapy
Identifiers
urn:nbn:se:umu:diva-140057 (URN)000410545600006 ()28860419 (PubMedID)
Available from: 2017-10-03 Created: 2017-10-03 Last updated: 2018-06-09Bibliographically approved
Alghadir, A., Zafar, H. & Iqbal, Z. A. (2017). Effect of upright and slouch sitting postures and voluntary teeth clenching on hand grip strength in young male adults. Journal of Back and Musculoskeletal Rehabilitation, 30(5), 961-965
Open this publication in new window or tab >>Effect of upright and slouch sitting postures and voluntary teeth clenching on hand grip strength in young male adults
2017 (English)In: Journal of Back and Musculoskeletal Rehabilitation, ISSN 1053-8127, E-ISSN 1878-6324, Vol. 30, no 5, p. 961-965Article in journal (Refereed) Published
Abstract [en]

BACKGROUND: Estimation of handgrip strength (HGS) is routinely used by clinicians and epidemiologists for objective assessment of functional status of hand and upper extremity. It is also used as an indirect indicator of overall physical strength and health status in variety of clinical situations and chronic general medical conditions. OBJECTIVE: The present study was conducted to examine the effects of upright and slouch sitting postures and voluntary teeth clenching on hand grip strength in healthy young male subjects. METHODS: One hundred healthy young males (aged 18-30 years) participated in this study. The HGS was measured using a commercially available dynamometer for the dominant hand. The HGS was measured during four test conditions; (a) slouch sitting without teeth contact, (b) slouch sitting with teeth clenching, (c) upright sitting without teeth contact, and (d) upright sitting with teeth clenching. RESULTS: The HGS values were significantly higher during slouch than upright sitting posture, both during similar and opposite teeth related conditions (p < 0.001). Teeth clenching had no effect on the in HGS values during slouch or upright sitting posture (P > 0.05). CONCLUSIONS: As compared to upright sitting, higher HGS values can be obtained during slouch sitting in young healthy males. Teeth clenching does not affect the HGS values during slouch or upright sitting posture.

Place, publisher, year, edition, pages
IOS PRESS, 2017
Keywords
Hand grip strength (HGS), sitting posture, teeth clenching
National Category
Physiotherapy
Identifiers
urn:nbn:se:umu:diva-140939 (URN)10.3233/BMR-150278 (DOI)000412063800003 ()28453449 (PubMedID)
Available from: 2017-10-20 Created: 2017-10-20 Last updated: 2018-06-09Bibliographically approved
Alghadir, A., Zafar, H., Iqbal, Z. A. & Al-Eisa, E. (2017). Work-Related Low Back Pain Among Physical Therapists in Riyadh, Saudi Arabia. Workplace Health & Safety, 65(8), 337-345
Open this publication in new window or tab >>Work-Related Low Back Pain Among Physical Therapists in Riyadh, Saudi Arabia
2017 (English)In: Workplace Health & Safety, ISSN 2165-0799, Vol. 65, no 8, p. 337-345Article in journal (Refereed) Published
Abstract [en]

Low back pain (LBP) is a common health problem. Professions like physical therapy (PT), involving frequent lifting, bending, or standing, are at risk for developing LBP. The objective of this study was to determine the prevalence of work-related LBP and factors associated with and consequences of work-related LBP among physical therapists in Riyadh, Saudi Arabia. A self-administered online questionnaire (i.e., demographic data, history of LBP before and after working as a physical therapist, work setting, and effect on daily activities) was sent to 600 members of the Saudi PT association. Data were analyzed using the Pearson chi-square test and Mann-Whitney U test. Eighty-eight percent of potential respondents completed the questionnaire. Of these, 89.65% of the therapists reported LBP after beginning their PT practice, and 35.6% reported LBP at the time of this survey. Gender, PT specialty, and duration of contact with patients were all found to be related to LBP. The prevalence of work-related LBP among physical therapist in Riyadh was high, affecting patient care and daily activities of the therapists. Both primary and secondary prevention strategies (e.g., introduce ergonomics into PT curricula, reduce therapist stress, and promote teamwork) are needed to decrease LBP among therapists, so they can effectively care for patients.

Keywords
work-related low back pain, physical therapy, physical therapists, risk factors
National Category
Dentistry
Identifiers
urn:nbn:se:umu:diva-138410 (URN)10.1177/2165079916670167 (DOI)000406598900004 ()
Available from: 2017-08-23 Created: 2017-08-23 Last updated: 2018-06-09Bibliographically approved
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