Department of Mechanical Engineering and Engineering Science, Center for Biomedical Engineering and Science, University of North Carolina at Charlotte, Charlotte, North Carolina, USA.
Tampa Bay Rays and the University of South Florida, Tampa, Florida, USA.
Am J Sports Med. 2021 Nov;49(13):3647-3655. doi: 10.1177/03635465211039850. Epub 2021 Sep 23.
Throwing arm injuries are common because of the demand on the shoulder. The shoulder is qualitatively checked regularly by team physicians. Excessive instability and joint loading in baseball pitching are risk factors for throwing arm injuries. Knowledge of shoulder flexibility, range of motion, and joint loading may provide new insights for treatments to reduce the likelihood of injury incidence.
To investigate the relationship among injuries, shoulder external rotational properties, and shoulder joint loading in baseball pitchers.
Descriptive laboratory study.
Pitching kinetics, shoulder rotational tests, and self-reported injury questionnaires were used to study 177 collegiate baseball pitchers. Pitching motion data were collected at 240 Hz using a motion capture system. A custom program calculated the shoulder joint loading. The shoulder rotational test quantitatively records shoulder range of motion and flexibility using a custom-made wireless device. Self-reported injury questionnaires were filled out during tests and yearly follow-ups. The total length of the study was 5 years. Analysis of variance, chi-square, and regression tests were performed to compare differences among groups and detect correlations with surgery and shoulder joint loadings.
There were significant differences in shoulder flexibility among surgery groups. Shoulder external rotational properties during physical examination were significantly associated with shoulder joint loading in baseball pitching. High shoulder external rotation was associated with 14% to 36% lower shoulder posterior force and adduction, internal rotation, and horizontal adduction torque ( < .05). High shoulder flexibility was associated with 13% higher anterior force ( < .05). High shoulder external rotation before external rotation torque was applied was associated with 13% to 33% lower shoulder inferior force and adduction, internal rotation, and horizontal adduction torque ( < .05). There were no significant differences in shoulder joint loading among the surgery groups.
Shoulder injuries that require surgery were associated with shoulder external rotation flexibility. High shoulder external rotation may be advantageous because it lowers the force and torque on the shoulder joint.
The ability to understand shoulder external rotational properties, joint loading, and injury during baseball pitching helps further our understanding of injury mechanisms. The shoulder rotational test should be used as a screening tool to identify players at risk.
由于肩部的需求，投掷臂受伤很常见。队医会定期对肩部进行定性检查。在棒球投球中，过度的不稳定和关节负荷是投掷臂受伤的危险因素。了解肩部柔韧性、运动范围和关节负荷可能为减少受伤发生率的治疗方法提供新的见解。
研究棒球投手中受伤、肩部外旋特性和肩关节负荷之间的关系。
描述性实验室研究。
使用 177 名大学生棒球投手的投球动力学、肩部旋转测试和自我报告的损伤问卷进行研究。使用运动捕捉系统以 240Hz 的频率收集投球运动数据。一个自定义程序计算了肩关节的负荷。肩部旋转测试使用定制的无线设备定量记录肩部运动范围和柔韧性。自我报告的损伤问卷在测试和每年的随访中填写。总研究时间为 5 年。进行方差分析、卡方检验和回归检验，以比较组间差异，并检测与手术和肩关节负荷的相关性。
手术组之间的肩部柔韧性存在显著差异。体检时的肩部外旋特性与棒球投球中的肩关节负荷显著相关。高肩外旋与肩后向力和内收、内旋、水平内收扭矩降低 14%至 36%（<0.05）相关。高肩部柔韧性与前向力增加 13%（<0.05）相关。在施加外旋扭矩之前，高肩外旋与肩下向力和内收、内旋、水平内收扭矩降低 13%至 33%（<0.05）相关。手术组之间的肩关节负荷没有显著差异。
需要手术的肩部损伤与肩部外旋柔韧性有关。高肩外旋可能是有利的，因为它降低了肩关节的力和扭矩。
了解棒球投球中肩部外旋特性、关节负荷和损伤的能力有助于进一步了解损伤机制。肩部旋转测试应作为一种筛选工具，以识别有受伤风险的运动员。
