Tsuruike Masaaki, Ellenbecker Todd S
Department of Kinesiology, San José State University, San José, CA, USA.
Physiotherapy Associates Scottsdale Sports Clinic, Scottsdale, AZ, USA.
J Shoulder Elbow Surg. 2016 Oct;25(10):1583-91. doi: 10.1016/j.jse.2016.03.004. Epub 2016 Jun 2.
The characteristics of scapular muscle activities in elevation and descent exercises have yet to be elucidated to assess scapular dyskinesis. The purpose of this study was to identify the adaptation of electromyograph (EMG) activities of the upper trapezius (UT), lower trapezius (LT), serratus anterior (SA), and anterior deltoid (AD) muscles with different weight loads in flexion (FLX) and abduction (ABD) in collegiate baseball players.
Twenty eight individuals, including 13 pitchers, were tested. Normalized EMG signals for the UT, LT, SA, AD muscle of the both the dominant (DOM) and nondominant (NON) side were blocked at every 1 second during each of the exercises. A 3-way repeated analysis of variance design was used to identify differences in the mean values between DOM and NON and between FLX and ABD for DOM.
The mean EMG value of the UT in the DOM was significantly less than that of the NON for all joint angles (P < .01), whereas the mean EMG value of the LT in the DOM was significantly greater than that of the NON (P < .01). In contrast, no difference in the SA EMG activity was determined between DOM and NON. However, the mean EMG value of SA in FLX was significantly greater than in ABD (P < .01).
This study identified an apparent adaptation of scapular muscle activities in the currently advocated scapular dyskinesis test for healthy active overhead athletes who are vulnerable to shoulder pathologies.
在评估肩胛运动障碍时，肩胛肌在抬高和下降运动中的活动特征尚未阐明。本研究的目的是确定大学棒球运动员在不同重量负荷下进行屈曲（FLX）和外展（ABD）运动时，斜方肌上束（UT）、斜方肌下束（LT）、前锯肌（SA）和三角肌前束（AD）肌肉的肌电图（EMG）活动的适应性。
对28名个体进行测试，其中包括13名投手。在每次运动过程中，每1秒记录优势侧（DOM）和非优势侧（NON）的UT、LT、SA、AD肌肉的标准化EMG信号。采用三因素重复方差分析设计，以确定DOM和NON之间以及DOM的FLX和ABD之间平均值的差异。
在所有关节角度下，DOM侧UT的平均EMG值均显著低于NON侧（P < 0.01），而DOM侧LT的平均EMG值显著高于NON侧（P < 0.01）。相比之下，DOM和NON之间的SA肌电活动没有差异。然而，FLX中SA的平均EMG值显著高于ABD（P < 0.01）。
本研究确定了在目前提倡的肩胛运动障碍测试中，肩胛肌活动在易患肩部疾病的健康活跃过头运动员中的明显适应性。
