Hodges and Richardson demonstrated
that when subjects performed a unilateral shoulder movement, the
transversus abdominis was the first of the trunk muscles to become
active, and this activation occurred prior to the onset of actual limb
movement.1 This study suggests that for the throwing athlete, core
stability would be important as force is transferred from the ground,
up through the lower extremities, across the trunk, and out to the
As force is transmitted to the throwing arm, stability is also required at the scapulothoracic joint (the joint between the rib cage and the shoulder blade) to transfer energy from the trunk to the shoulder. As the arm accelerates it puts tremendous strain on the glenohumeral joint which also requires stability to prevent injury to the rotator cuff and joint capsule.
It has been shown that with weakness of the rotator cuff, the pitcher uses the deltoid excessively, resulting in impingement of the rotator cuff.2 Weakness of the scapular stabilizer, serratus anterior results in excessive anterior and superior translation of the humeral head. This can lead to impingement of the rotator cuff tendons and strain to the joint capsular structures.
1. Hodges, P. W., & Richardson, C. A. (1996). Inefficient muscular stabilization of the lumbar spine associated with low back pain: a motor control evaluation of transversus abdominis. Spine, 21(22), 2640-2650.
2. Brumitt, J., & Dale, R. B. (2009). Integrating shoulder and core exercises when rehabilitating athletes performing overhead activities. North American journal of sports physical therapy: NAJSPT, 4(3), 132.
The best shoulder workout for throwing includes technical training, strength and endurance training, core stability training with the exercise ball (also known as the swiss ball, ab ball, balance ball, fit ball, gymnic ball, fitness ball, therapy ball, physio ball, etc.) as well as exercises as prescribed by your pitching coach.