Results suggest that the functional consequences associated with scapular dyskinesis may compromise supraspinatus tendon healing after repair by diminishing some tendon mechanical properties. Identification of abnormal joint mechanics as a potential mechanical mechanism of failed rotator cuff healing will help guide clinicians in prescribing treatment strategies for patients with cuff tears. This study supports the need to evaluate joint kinematics and to consider correction of these abnormalities before surgical repair. This may allow optimization of the mechanical loading environment and result in improved tendon healing rates.