Bilateral deficits in muscle contraction parameters during shoulder scaption in patients with unilateral subacromial impingement syndrome

Objective: To evaluate muscle contraction parameters during scaption of the shoulder in patients with subacromial impingement syndrome (SIS). Method: Thirty-three male subjects were evaluated. The impingement group consisted of 17 assembly line workers (31.6 ± 6.4 years) with unilateral SIS. The control group consisted of 16 healthy and active subjects (29.5 ± 6.2 years). Acceleration time, time to peak torque, peak torque, total work and power were measured bilaterally during isokinetic concentric scaption, at 60°/s and 180°/s. Results: None of the isokinetic parameters differed bilaterally in the SIS group but compared to the control group showed impaired muscle activity in all parameters at both speeds (P< 0.05). Conclusions: Muscle contraction parameters are altered in both involved and uninvolved shoulders during scaption in patients with SIS.