Subacromial impingement syndrome: the effect of changing posture on shoulder range of movement.

STUDY DESIGN Random allocation of subjects into a placebo-controlled, crossover study. OBJECTIVES To investigate the effect of changing thoracic and scapular posture on shoulder flexion and scapular plane abduction range of motion in asymptomatic subjects, and in subjects with subacromial impingement syndrome. BACKGROUND Changes in upper body posture and concomitant imbalance of the muscle system have been proposed as one of the etiological mechanisms leading to subacromial impingement syndrome. Although clinicians commonly assess posture and devise rehabilitation programs to correct posture, there is little evidence to support this practice. METHODS AND MATERIALS Selected postural, range of movement, and pain measurements were investigated in 60 asymptomatic subjects and 60 subjects with subacromial impingement syndrome, prior to and following thoracic and scapular taping intended to change their posture. RESULTS Changing posture had an effect on all components of posture measured (P<.001) and these changes were associated with a significant increase (P<.001) in the range of motion in shoulder flexion and abduction in the plane of the scapula. Changing posture was not found to have a significant effect on the intensity of pain experienced by the symptomatic subjects, although the point in the range of shoulder elevation at which they experienced their pain was significantly higher (P<.001). CONCLUSIONS The findings of this investigation suggest that changing 1 or more of the components of posture may have a positive effect on shoulder range of movement and the point at which pain is experienced.