Popchak Adam J, Hogaboom Nathan S, Vyas Dharmesh, Abt John P, Delitto Anthony, Irrgang James J, Boninger Michael L
1Department of Physical Therapy, University of Pittsburgh, Pittsburgh, PA; 2Department of Rehabilitation Science and Technology, University of Pittsburgh, Pittsburgh, PA; 3Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, PA; 4Sports Medicine Research Institute, College of Health Sciences, University of Kentucky, Lexington, KY; 5School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, PA; 6Human Engineering Research Laboratories, VA Pittsburgh Healthcare System, Pittsburgh, PA; 7Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA; and 8Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA.
Med Sci Sports Exerc. 2017 Jun;49(6):1168-1175. doi: 10.1249/MSS.0000000000001205.
Youth baseball frequently results in repetitive strain injuries. Quantitative ultrasound allows real-time imaging with the ability to identify acute markers of tendon change. The study objective was to determine acute quantitative ultrasound changes in the long head of the biceps and infraspinatus tendons of the throwing and nonthrowing shoulders during a pitching performance. We hypothesized the tendons of the pitching arm would exhibit an increased width and decreased echogenicity after pitching and that tendons of the nonpitching arm would not demonstrate such changes.
Fifty youth baseball players, ages 9-14 yr, engaged in a simulated pitching performance that consisted of 50 pitches. Subjects underwent serial quantitative ultrasound imaging of the infraspinatus and the long head of the biceps before pitching and after 25 and 50 pitches were thrown.
Testing of the change in tendon width revealed the infraspinatus (0.21 mm) and long head of the biceps tendons (0.18 mm) in the throwing shoulder had statistically significant increases (P = 0.03) in tendon width as an acute response to throwing 50 pitches, without such changes in the nonthrowing shoulder (P > 0.05). No tendon width change was found at 25 pitches in either arm or tendon (P > 0.05). No associated changes in echogenicity were found at any time point (P > 0.05).
The results of this study suggest that pitching acutely increases tendon width in two biomechanically important tendons of the shoulder as early as the 50 pitch mark. This change could be a normal physiological response or a potential warning sign of future pathology and requires further study.
青少年棒球运动经常导致重复性劳损损伤。定量超声能够进行实时成像，具备识别肌腱变化急性标志物的能力。本研究的目的是确定在投球过程中，投掷肩和非投掷肩的肱二头肌长头肌腱和冈下肌腱的急性定量超声变化。我们假设投球手臂的肌腱在投球后会出现宽度增加和回声性降低的情况，而非投球手臂的肌腱不会出现此类变化。
50名年龄在9至14岁的青少年棒球运动员参与了一项由50次投球组成的模拟投球表现测试。受试者在投球前以及投出25次和50次球后，接受了冈下肌和肱二头肌长头肌腱的系列定量超声成像检查。
对肌腱宽度变化的测试显示，投掷肩的冈下肌腱（0.21毫米）和肱二头肌长头肌腱（0.18毫米）在投出50次球后，作为对投球的急性反应，肌腱宽度出现了具有统计学意义的增加（P = 0.03），而非投掷肩没有此类变化（P > 0.05）。在投出25次球时，无论是哪只手臂或肌腱，均未发现肌腱宽度变化（P > 0.05）。在任何时间点均未发现回声性的相关变化（P > 0.05）。
本研究结果表明，早在投出50次球时，投球就会急性增加肩部两个生物力学上重要肌腱的宽度。这种变化可能是正常的生理反应，也可能是未来病理状况的潜在警示信号，需要进一步研究。
