Effect of Motor Control and Strengthening Exercises on Shoulder Function in Persons with Impingement Syndrome: a Single-subject Study Design

The aim of the study was to evaluate the effect of an intervention including shoulder control and strengthening exercises on function in persons with shoulder impingement. Eight subjects with shoulder impingement were evaluated weekly during the nine weeks of this single-subject design study. The study was divided into three phases (A(1)-B-A(2)) and involved repeated measures of shoulder pain and function (Shoulder Pain And Disability Index (SPADI) questionnaire), painful arc of motion, peak torque and 3-dimensional scapular attitudes. During the intervention phase, each subject participated in 12 exercise sessions supervised by a physiotherapist. Measures taken during the intervention and post-intervention phases were compared to pre-intervention values. All subjects showed significant improvement in the SPADI at the end of the study. A disappearance of a painful arc of motion in flexion and abduction (n=6), an increase in isometric peak torque in lateral rotation (n=3) and abduction (n=2), and changes in the scapular kinematics, mainly in the sagittal plane, were also observed. The present results provide preliminary evidence to support the use of shoulder control exercises to reduce pain and improve function of persons with shoulder impingement.