RESTING AND THERAPIST-CORRECTED ORIENTATION OF THE SCAPULA IN PEOPLE WITH AND WITHOUT A HISTORY OF SHOULDER PAIN
1University of Southampton, Faculty of Health Sciences, Southampton, United Kingdom, 2University of Southampton, School of Electronics and Computer Science, Southampton, United Kingdom, 3Queen Mary University of London, Centre for Sports and Exercise Medicine, London, United Kingdom
Purpose: The aim was to evaluate scapular position at rest and in a therapist-corrected neutral position in people with and without a history of shoulder pain.
Relevance: Clinical observation suggests that scapular orientation and posture are altered in patients with shoulder pain. Correction strategies have therefore been advocated as part of the intervention but differences in resting or corrected posture have not been reported objectively.
Participants: Nineteen people were studied: 13 (9 female) healthy controls (mean age 30.6 years, SD±9.1) and six (5 males) with a history of shoulder pain (aged 44.3 ±14.7).
Methods: A static recording of the resting (natural) position of the right scapula was made using a six-camera Vicon 460 (Oxford, UK) motion capture system. The examiner then manually placed the scapula into the neutral position, i.e. mid-point of all directions of scapular motion, which was maintained by the participant while a static motion capture recording was made.
Analysis: Kinematic data were processed using a model following the International Society of Biomechanics guidelines (Wu et al., 2005). Scapular kinematics were expressed in degrees of external/internal, upward/downward rotation, and anterior/posterior tilt. A repeated measures ANOVA examined significant within and between-group differences in scapular repositioning. Post-hoc analysis used paired samples t-tests with a Bonferroni correction. Wu G et al. (2005) J Biomech 38 :981-992123.
Results: The history of pain group showed a significant increase (p<0.025) in upward scapular rotation from the resting (-8.6O ± 8.6) to the 'neutral' position (-5.1 ± 8.0). No significant differences were found for the other two scapular rotations in this group, or any rotations in the control group. There were no differences between groups for any scapular orientations in either of the two positions tested.
Conclusions: The history of pain group showed a greater increase in upward rotation than controls when positioned in 'neutral'. Research is required to evaluate the effect of a retraining strategy for restoring and maintaining scapular position to improve the biomechanics of the shoulder complex and improve function.
Implications: The significant increase in upward rotation from resting to neutral postures indicates that people with a history of shoulder pain have abnormal resting posture in downward rotation, supporting clinical observations.
Key-words: 1. Scapula 2. Kinematics 3. Posture
Funding acknowledgements: We thank the participants, Faizura Fadzil for technical assistance, the Private Physiotherapy Educational Foundation (UK) for funding and Vicon Motion Systems (Oxford, UK) for a PhD studentship (M Warner).
Ethics approval: School of Health Professions and Rehabilitation Sciences Ethics Committee, University of Southampton, UK.
MUSCULOSKELETAL: Upper Limb 4
Professional Practice - MUSCULOSKELETAL: Upper Limb
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