Differences in Scapular Upward Rotation between Baseball Pitchers and Position Players

Abstract

This decrease in scapular upward rotation may compromise the integrity of the glenohumeral joint and place pitchers at an increased risk of developing shoulder injuries compared with position players. As such, pitchers may benefit from periscapular stretching and strengthening exercises to assist with increasing scapular upward rotation.

Clinical Measurement of Scapular Upward Rotation in Response to Acute Subacromial Pain

“…The inclinometer was modified by attaching 2 wooden palpation dowels to the bottom of the instrument. 8,11,28,35 Upward/downward rotation of the scapula was measured relative to horizontal by aligning the indented Y of each palpation dowel along the medial and lateral aspect of the scapular spine (FIGURE 1). 8,11,37 Prior research has indicated that measurement of scapular upward/ downward rotation with a modified digital inclinometer is a reliable procedure.…”

“…8,11,28,35 Upward/downward rotation of the scapula was measured relative to horizontal by aligning the indented Y of each palpation dowel along the medial and lateral aspect of the scapular spine (FIGURE 1). 8,11,37 Prior research has indicated that measurement of scapular upward/ downward rotation with a modified digital inclinometer is a reliable procedure. 8,11 A priori reliability testing of 15 healthy participants, tested twice over a 48-hour period, was performed by the principal investigator.…”

“…8,11,37 Prior research has indicated that measurement of scapular upward/ downward rotation with a modified digital inclinometer is a reliable procedure. 8,11 A priori reliability testing of 15 healthy participants, tested twice over a 48-hour period, was performed by the principal investigator. The reliability of the measurement of scapular upward/downward rotation was calculated using an intraclass correlation coefficient (ICC 3,1 ) and standard error of measurement (SEM) for the following angles: arms at rest (ICC = 0.87; SEM, 0.87°), 30° (ICC = 0.94; SEM, 0.92°), 60° (ICC = 0.97; SEM, 0.89°), 90° (ICC = 0.97; SEM, 0.84°), and 120° (ICC = 0.96; SEM, 0.86°).…”

“…To be consistent with previous research, scapular upward rotation was measured at 5 angles of humeral elevation in the scapular plane: rest position (arms at side), 30°, 60°, 90°, and 120°. 8,11 The measurement of humeral elevation was performed with the digital inclinometer immediately prior to scapular measurement. Scapular measurements, which were relative to horizontal and not to the thorax, were recorded during the pain and no-pain conditions.…”

Assessment of Subacromial Space and Its Relationship With Scapular Upward Rotation in College Baseball Players

“…1,9,[22][23][24][25] Several studies have demonstrated alterations in scapular position or motion in injured and healthy overhead athletes. 8,9,19,26 These studies have commonly observed decreased amounts of scapular upward rotation, 8,9,19,27 which is thought to decrease the subacromial space by approximating the acromion with the humerus. However, this relationship has yet to be determined in healthy college baseball players.…”