Lintner David, Mayol Magdiel, Uzodinma Obinna, Jones Rex, Labossiere David
Methodist Center for Sports Medicine, The Methodist Hospital, Houston, TX 77030, USA.
Am J Sports Med. 2007 Apr;35(4):617-21. doi: 10.1177/0363546506296736. Epub 2007 Feb 9.
Repetitive throwing motion creates increased external rotation and decreased internal rotation in the glenohumeral joint. There is controversy regarding the contribution of osseous and soft tissue adaptations to these changes in rotation.
To evaluate internal rotation deficits in the professional baseball thrower's shoulder and determine the impact of an internal rotation stretch program on that deficit.
Cross-sectional study; Level of evidence, 3.
Eighty-five male professional pitchers were evaluated in this study. Players were divided into 2 groups based on length of participation in an appropriate internal rotation stretch program. Data were collected on internal and external rotations and total range of motion in both dominant and nondominant arms using a goniometer. Internal rotation deficit (the lack of internal rotation relative to the opposite side) was calculated. Generalized comparative statistical tests were used.
Pitchers with 3 or more years in a stretch program (group 1) had greater internal rotation (74.3 degrees vs 54.3 degrees ) and greater total range of motion (217.0 degrees vs 194.2 degrees ) in dominant shoulders than did pitchers with less than 3 years (group 2). Total range of motion was greater in the dominant than in the nondominant arm for group 1. Internal rotation deficit in dominant arms was significantly greater for group 2 than for group 1. The analysis of dominant arm rotation relative to years in an internal rotation stretching program for pitchers in both groups showed a progressive increase in both internal rotation and total arc of motion with the number years in such a program plateauing after year 3.
The throwing motion shifts the total arc of motion toward external rotation and diminishes internal rotation. The increased external rotation may be attributable to increased humeral retroversion. The internal rotation deficit, however, is caused by soft tissue adaptations that can be addressed by consistent participation in a stretching program focused on internal rotation.
重复性投掷动作会使盂肱关节的外旋增加而内旋减少。关于骨组织和软组织适应性变化对这些旋转改变的作用存在争议。
评估职业棒球投手肩部的内旋不足，并确定内旋拉伸训练计划对该不足的影响。
横断面研究；证据等级为3级。
本研究评估了85名男性职业投手。根据参与适当内旋拉伸训练计划的时长，将球员分为两组。使用角度计收集优势臂和非优势臂的内旋、外旋以及总活动范围的数据。计算内旋不足（相对于对侧的内旋缺失）。采用广义比较统计检验。
参与拉伸训练计划3年或更长时间的投手（第1组）优势肩部的内旋角度（74.3度对54.3度）和总活动范围（217.0度对194.2度）均大于参与时间少于3年的投手（第2组）。第1组优势臂的总活动范围大于非优势臂。第2组优势臂的内旋不足显著大于第1组。对两组投手优势臂旋转角度与参与内旋拉伸训练计划年限的分析表明，随着参与该计划年限的增加，内旋和总活动弧度均逐渐增加，在第3年后趋于平稳。
投掷动作使总活动弧度向外旋方向偏移并减少内旋。外旋增加可能归因于肱骨后倾增加。然而，内旋不足是由软组织适应性变化引起的，通过持续参与专注于内旋的拉伸训练计划可以改善。
