Do Scapular Kinematics Alter during the Performance of the Scapular Assistance Test and Scapular Retraction Test: A Pilot Study

Objective: To describe to what degree and in what plane biomechanical alterations occur during the performance of the Scapular Retraction test (SRT) and Scapular Assistance Test (SAT). Design: Laboratory Pilot Study Participants: Eight symptomatic and 7 asymptomatic subjects were instrumented with electromagnetic sensors. Main Outcome Measures: The SRT and SAT were performed with the scapula stabilized and unstabilized. The scapular kinematic variables of posterior tilt, internal rotation, upward rotation, protraction, and elevation were measured during both tests. Results: Descriptive analysis of scapular kinematics suggested that posterior tilt was primarily increased during both clinical tests in both groups. Both groups decreased in scapular elevation, indicating that the scapula was being depressed during the SRT. There was no meaningful change in force during the SRT. Conclusion: These findings indicate that both the SRT and SAT appear to alter scapular motion in both groups. The interpretations of these results are limited due to the small sample size and large confidence intervals, but suggest that these tests change specific positions of the scapula. Further research into these tests is needed to confirm these biomechanical alterations, and to determine the value of these tests when developing rehabilitation protocols in patients with shoulder pain.