A bilateral comparison of posterior capsule thickness and its correlation with glenohumeral range of motion and scapular upward rotation in collegiate baseball players

Humeral retroversion and its association with posterior capsule thickness in collegiate baseball players

“…26 Paired-sample t tests showed that humeral retroversion of the dominant arm was significantly greater compared with the nondominant arm (P ¼ .0001) (Fig. 1).…”

“…A previous cadaveric study was performed to validate the identification of the posterior capsule. 26 Before the start of this study, a priori intratester and test-retest reliability of posterior capsule thickness was assessed by the primary investigator. Twenty-two healthy shoulders were measured 3 separate times during the same testing session and remeasured 3 to 5 days later.…”

“…The posterior capsule was identified as the tissue just off the tip of the labrum between the humeral head and rotator cuff. 26 When the capsule was identified, the image was frozen, saved to the hard drive, and removed after testing was complete for analysis. The image was then imported into ImageJ software (National Institutes of Health, Bethesda, MD, USA), and the posterior capsule thickness was measured and recorded.…”

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.…”

Reliability and validity in measurement of true humeral retroversion by a three-dimensional cylinder fitting method

“…20 Humeral retroversion as well as posterior capsule thickness has a considerable influence on shoulder range of motion, including decreased glenohumeral internal rotation. 19,26,31 Baseball players exhibiting a decrease in passive internal rotation !25 in the dominant shoulder were approximately 4 to 5 times at greater risk of an upper extremity disorder than were players with <25 decrease in passive internal rotation. 29 Various methods using radiography, 22,26 computed tomography (CT), 2,7,18 or ultrasonography [18][19][20]23,32,[34][35][36][38][39][40] have been proposed to measure the humeral retroversion angle; however, no widely accepted standard method exists.…”