Objective: The purpose of this study is to compare muscle activation pattern between patients with shoulder impingement syndrome and healthy subjects during selected functional task.
Materials & Methods: In this comparative and case-control study, fifteen patients with shoulder impingement syndrome as case group were selected simply and conveniently from Avesta orthopedic clinic and fifteen healthy subjects as control group were selected on the basis of matching with patients. In each group selected exercises including open kinetic chain with and without external load and closed kinetic chain with axial load was done and during each exercises surface electromyography (EMG) from selected muscle including Superior Trapezius, Infraspinatus and Anterior, Middle and Posterior Deltoid recorded. Independent T-test used for data analysis.
Results: Generally two groups showed different muscle activity during kinetic chain exercises. There were significant differences in relative muscle latency times between two groups in superior Trapezius, Infraspinatus and three regions of Deltoid muscle (P<0.05).
Conclusion: Changes in muscle recruitment pattern are task dependent that this may be due to direction of movement and axial compression loading in subacromial space. Among all selected exercises in D2E (Diagonal 2 Extension) minimum changes and in tripod maximum changes (in time domain) were seen.