| Budget Amount *help |
¥3,640,000 (Direct Cost: ¥2,800,000、Indirect Cost: ¥840,000)
Fiscal Year 2010: ¥520,000 (Direct Cost: ¥400,000、Indirect Cost: ¥120,000)
Fiscal Year 2009: ¥3,120,000 (Direct Cost: ¥2,400,000、Indirect Cost: ¥720,000)
|
|---|
| Research Abstract |
Background : Although deviations in scapular orientation are thought to result in shoulder injuries in throwing athletes, the biomechanical mechanism underlying shoulder injuries in throwing athletes caused by altered scapular orientation has not been clarified.
Methods : Seven fresh frozen cadaveric shoulders were evaluated at 90° abduction, with the humerus externally rotated from 90° to the maximum angle, to simulate the late cocking phase of the throwing motion. Loads were applied to the deltoid, pectoralis major, latissimus dorsi, teres major muscles, and all rotator cuff muscles. Contact pressure in the glenohumeral joint was measured using a pressure sensor. The area of internal impingement was calculated based on three-dimensional location data. Glenohumeral contact pressure and area of impingement were compared between 20°, 30°, and 40° of internal scapular rotation, between 20°, 30°, and 40° of upward scapular rotation, and between 0° and 10° of anterior scapular tilt. Data we
… More
re analyzed using repeated measures ANOVA with Tukey's post hoc test (P<0.05).
Results : Contact pressure was detected in the posterior glenohumeral joint. The glenohumeral contact pressure and internal impingement area increased with increasing internal scapular rotation. The glenohumeral contact pressure (by 43.4%, p<0.01) and impinged area (by 43.1%, p<0.05) at 40° of internal scapular rotation were significantly greater than those at 20°of internal scapular rotation. Decreasing upward scapular rotation resulted in an increase in internal impingement area. The impinged area at 20° (by 38.1%, p<0.0001) and 30° (by 28.9%, p<0.01) of upward scapular rotation were significantly greater than that at 40° of upward scapular rotation.
Conclusions : Increasing internal scapular rotation and decreasing upward scapular rotation significantly increase glenohumeral contact pressure and/or impinged area of the rotator cuff tendon between the greater tuberosity and glenoid during simulated throwing motion.
Clinical Relevance : Shoulder internal impingement is accentuated by increasing internal rotation or decreasing upward rotation of the scapula during throwing motion. Less
|
