Department of Rehabilitation, Toyota Memorial Hospital, Toyota, Japan.
Department of Rehabilitation, Yokohama Sports Medical Center, Yokohama, Japan.
J Shoulder Elbow Surg. 2021 Jun;30(6):1309-1315. doi: 10.1016/j.jse.2021.01.039. Epub 2021 Mar 3.
Pitching mechanics are believed to be risk factors for throwing elbow injury. Thus, a prospective study of abnormal mechanics in youth baseball players is needed. This study aimed to analyze the ulnar collateral ligament during normal pitching using SIMM (Software for Interactive Musculoskeletal Modeling) for analysis and investigate the risk parameters of throwing elbow injuries in youth baseball players. We hypothesized that excessive ulnar collateral ligament force during pitching would be a risk factor for throwing elbow injuries in this population.
In this cohort study, youth baseball pitchers (aged 9-11 years) were instructed to throw a ball into a netted target. Using a SIMM musculoskeletal model, we analyzed the force of the anterior band of the anterior oblique ligament, posterior band of the anterior oblique ligament (AOL_PB), and elbow varus moment during pitching (foot contact to ball release). We calculated the integral of each force of the anterior band of the anterior oblique ligament and AOL_PB during pitching and summarized these data to establish an impulse at the medial epicondyle. Each participant was followed up for 12 months to assess the occurrence of throwing elbow injury.
During the 12-month follow-up period, 18 pitchers (28.1%) reported throwing elbow injuries in the throwing arm. The results of this study showed that the maximum AOL_PB force and the impulse at the medial epicondyle were risk factors for throwing elbow injuries. The maximum AOL_PB force was significantly higher in the throwing elbow injury group than in the uninjured group (59.4 ± 17.8 N vs. 47.1 ± 17.5 N, P = .014). The impulse at the medial epicondyle was also significantly different (11.1 ± 4.0 N ･ s in the throwing elbow injury group vs. 8.3 ± 4.4 N ･ s in the uninjured group, P = .025).
Increasing the AOL_PB force or the impulse at the medial epicondyle may increase the risk of throwing elbow injuries in youth baseball pitchers. It may be possible to reduce injury risk by focusing on ways to decrease AOL_PB load and cumulative stress on the medial epicondyle throughout the throwing motion while still maintaining high levels of ball velocity.
投球力学被认为是投掷肘伤的危险因素。因此，需要对青年棒球运动员的异常力学进行前瞻性研究。本研究旨在使用 SIMM（交互式肌肉骨骼建模软件）分析正常投球时的尺侧副韧带，并研究青年棒球运动员投掷肘伤的风险参数。我们假设在投球过程中尺侧副韧带的力过大将是该人群投掷肘伤的一个危险因素。
在这项队列研究中，我们指导青年棒球投手（9-11 岁）将球投进网袋状目标。使用 SIMM 肌肉骨骼模型，我们分析了投球时前斜韧带前束（AOL_PB）和肘内翻力矩的力。我们计算了投球过程中前斜韧带前束和 AOL_PB 的每个力的积分，并将这些数据汇总以在内上髁建立一个冲量。每个参与者都进行了 12 个月的随访，以评估投掷肘伤的发生情况。
在 12 个月的随访期间，18 名（28.1%）投手报告在投球臂发生投掷肘伤。这项研究的结果表明，最大 AOL_PB 力和内上髁冲量是投掷肘伤的危险因素。受伤组的最大 AOL_PB 力明显高于未受伤组（59.4 ± 17.8 N 比 47.1 ± 17.5 N，P =.014）。内上髁冲量也有显著差异（受伤组为 11.1 ± 4.0 N ･ s，未受伤组为 8.3 ± 4.4 N ･ s，P =.025）。
增加 AOL_PB 力或内上髁冲量可能会增加青年棒球投手投掷肘伤的风险。通过关注在投球过程中降低 AOL_PB 负荷和对内上髁的累积应力的方法，同时保持高球速，可能会降低受伤风险。
