Study Design: Single-group repeated-measures design. Objectives: To investigate the ability of the wall slide exercise to activate the serratus anterior muscle (SA) at and above 90° of humeral elevation. Background: Strengthening of the SA is a critical component of rehabilitation for patients with shoulder impingement syndromes. Traditional SA exercises have included scapular protraction exercises such as the push-up plus. These exercises promote activation of the SA near 90° of humeral elevation, but not in positions above 90° where patients typically experience pain. Methods and Measures: Twenty healthy subjects were studied performing 3 exercises: (1) wall slide, (2) plus phase of a wall push-up plus, and (3) scapular plane shoulder elevation. Three-dimensional position of the thorax, scapula, and humerus and muscle activity from the SA, upper and lower trapezius, and latissimus dorsi were recorded. The magnitudes of activation for each muscle at 90°, 120°, and 140° of humeral elevation were quantified from EMG records. Repeated-measures analyses of variance were used to determine the degree to which the different exercises activated the SA at the 3 humeral positions. Results: The intensity of SA activity was not significantly different between the 3 exercises at 90° of humeral elevation (P = .40). For the wall slide and scapular plane shoulder elevation exercises, SA activity increased with increasing humeral elevation angle (P = .001), with no significant differences between the 2 exercises (P = .36). Conclusion: The wall slide is an effective exercise to activate the SA muscle at and above 90° of shoulder elevation. During this exercise, SA activation is not significantly different from SA activation during the push-up plus and scapular plane shoulder elevation, 2 exercises previously validated in the literature. 

J Orthop Sports Phys Ther. 2006; 36(12):903-910. doi:10.2519/jospt.2006.2306 

Key Words: electromyography, scapula, shoulder