Contrast of Maximum Functional Torque in the Shoulder Joint in Overhead Athletes with and without Sub-acromion Impingement during Sitting Throw

Throwing movements are repetitive motions in overhead athletes that cause soft tissue adaptations and ultimately lead to shoulder joint damage. The current study purposed to determine the torque of internal and externalrotation of joint shoulder in overhead athletes with and without impingement syndrome in the ball throwing position.

This cross-sectional study was conducted on 63 male overhead athletes (33 with and 30 without shoulder impingement syndrome(. Simulated maximum functional torque was evaluated while the athlete threw a ball into a net from a sitting position. A 6-camera Vicon Motion Capture system incorporated markers on the upper limb and trunk. A kinematic model of the upper limb was used in OpenSim software with inverse dynamics to obtain maximum torque.

The internal and external rotation and elevation torques differed significantly in athletes with shoulder impingement syndrome compared to those without impingement syndrome (P<0.001, P=0.012, and P<0.001,respectively), while no significant difference was seen in shoulder depression (P=0.283) between the two groups.

The current findings suggest that there may be adaptations to shoulder strength and torque in response to throwing a ball that ultimately cause injury to the shoulder.