Abstract

Context: Proper scapulothoracic motion is critical for the health and function of the shoulder and represents a principal focus in the rehabilitation setting. Variants of the traditional push-up are used frequently to help restore proper scapular kinematics. To date, substantial research has focused on muscle activation levels of rotator cuff and scapular-stabilizing musculature, whereas a dearth of literature exists regarding scapular kinematics during push-up variants. Objective: To examine the effect of shoulder position on scapular kinematics across the range of motion (ROM) of a traditional push-up. Design: Cross-sectional study. Setting: University laboratory. Patients or Other Participants: Sixteen healthy participants without a history of upper extremity or spine injury requiring rehabilitation or surgery. Intervention(s): Participants performed a traditional push-up while kinematic measurements were acquired from multiple upper extremity segments. The 3 shoulder position conditions were (1) self-selected position, (2) shoulder adducted upon ascent (at side), and (3) shoulder elevated to approximately 90°. Main Outcome Measure(s): Scapular posterior tilt, upward rotation, and external rotation were examined across elbow-extension ROM and compared across conditions. Results: Posterior tilt was greater in the self-selected and at-side conditions than in the elevated condition and increased linearly with elbow extension. External rotation was greater in the self-selected and at-side conditions compared with that in the elevated condition. In the at-side condition, upward rotation began lower than in the other conditions at the start of the concentric phase but increased above the others soon after the elbow started to extend. Conclusions: Performing a traditional push-up with the shoulders elevated may place the scapula in a position of impingement. Clinicians should be cognizant of shoulder elevation when prescribing and monitoring exercise progression. The results of this study will provide further direction for clinicians in prescribing rehabilitation exercises for the upper extremity, especially closed chain exercises for shoulder conditions. Verf.-Referat