Takenaga Tetsuya, Sugimoto Katsumasa, Goto Hideyuki, Nozaki Masahiro, Fukuyoshi Masaki, Tsuchiya Atsushi, Murase Atsunori, Ono Tetsuya, Otsuka Takanobu
Department of Orthopaedic Surgery, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan Nagoya Sports Clinic, Nagoya, Japan
Nagoya Sports Clinic, Nagoya, Japan.
Am J Sports Med. 2015 Dec;43(12):2935-42. doi: 10.1177/0363546515608476. Epub 2015 Oct 15.
Posterior and posteroinferior capsules in the shoulder joints of throwing athletes have been reported to be thicker in throwing than nonthrowing shoulders, and this has a relationship to glenohumeral internal rotation deficit (GIRD). However, the stiffness of these thickened capsules has not been reported. Shear-wave ultrasound elastography is a new technology that can measure tissue elasticity quantitatively.
The posterior and posteroinferior capsules are stiffer as well as thicker in the throwing shoulders of baseball players than in their nonthrowing shoulders. The thickness and elasticity of these capsules are inversely correlated with glenohumeral internal rotation.
Cross-sectional study; Level of evidence, 3.
Forty-five male college baseball players were examined. The thickness and elasticity of the posterior capsule beneath the infraspinatus and the posteroinferior capsule beneath the teres minor were measured using an ultrasonic device equipped with shear-wave elastographic technology. Glenohumeral internal rotation at 90° of shoulder abduction and humeral retrotorsion were also measured.
The mean thickness and elasticity of the posterior capsule were significantly greater for the throwing compared with the nonthrowing shoulder (thickness: 1.34 vs 1.04 mm, respectively; elasticity: 40.0 vs 32.2 kPa, respectively; P < .001 for both). The mean thickness and elasticity of the posteroinferior capsule were also significantly greater in the throwing compared with the nonthrowing shoulder (thickness: 1.40 vs 1.04 mm, respectively; elasticity: 39.4 vs 31.6 kPa, respectively; P < .001 for both). After correcting the range of motion for bilateral differences in retrotorsion, correlation coefficients showed that posterior capsule thickness and elasticity (Pearson r = -0.43 and -0.56, respectively; P < .001 for both) and posteroinferior capsule thickness and elasticity (Pearson r = -0.51 and -0.52, respectively; P < .001 for both) were negatively correlated with the corrected glenohumeral internal rotation. Bilateral differences in posterior and posteroinferior capsule elasticity correlated with bilateral differences in the corrected glenohumeral internal rotation (Pearson r = 0.46 [P = .0015] and 0.48 [P < .001], respectively), whereas bilateral differences in posterior and posteroinferior capsule thickness did not (Pearson r = -0.13 [P = .38] and 0.17 [P = .28], respectively).
The posterior and posteroinferior capsules were stiffer as well as thicker in the throwing shoulder of college baseball players compared with the nonthrowing shoulder. Posterior capsule elasticity appeared to have a greater effect on GIRD than did posterior capsule thickness. This technology could be used as a noninvasive screening method for throwing athletes to identify players at potential risk of shoulder injuries.
据报道，投掷运动员肩关节的后囊和后下囊在投掷侧比非投掷侧更厚，这与盂肱关节内旋不足（GIRD）有关。然而，这些增厚囊的刚度尚未见报道。剪切波超声弹性成像技术是一种能够定量测量组织弹性的新技术。
棒球运动员投掷侧肩部的后囊和后下囊不仅更厚而且更硬。这些囊的厚度和弹性与盂肱关节内旋呈负相关。
横断面研究；证据等级：3级。
对45名男性大学棒球运动员进行检查。使用配备剪切波弹性成像技术的超声设备测量冈下肌下方后囊和小圆肌下方后下囊的厚度和弹性。同时测量肩关节外展90°时的盂肱关节内旋和肱骨后旋。
与非投掷侧相比，投掷侧后囊的平均厚度和弹性显著更大（厚度分别为1.34 vs 1.04 mm；弹性分别为40.0 vs 32.2 kPa；两者P均<0.001）。与非投掷侧相比，投掷侧后下囊的平均厚度和弹性也显著更大（厚度分别为1.40 vs 1.04 mm；弹性分别为39.4 vs 31.6 kPa；两者P均<0.001）。在纠正双侧后旋差异后的活动范围后，相关系数显示后囊厚度和弹性（Pearson相关系数分别为-0.43和-0.56；两者P均<0.001）以及后下囊厚度和弹性（Pearson相关系数分别为-0.51和-0.52；两者P均<0.001）与纠正后的盂肱关节内旋呈负相关。后囊和后下囊弹性的双侧差异与纠正后的盂肱关节内旋双侧差异相关（Pearson相关系数分别为0.46[P = 0.0015]和0.48[P < 0.001]），而后囊和后下囊厚度的双侧差异则无相关性（Pearson相关系数分别为-0.13[P = 0.38]和0.17[P = 0.28]）。
与非投掷侧相比，大学棒球运动员投掷侧肩部的后囊和后下囊更厚且更硬。后囊弹性对GIRD的影响似乎比后囊厚度更大。这项技术可作为一种非侵入性筛查方法，用于识别有肩部损伤潜在风险的投掷运动员。
