Miura Kazutomo, Tsuda Eiichi, Kogawa Masakazu, Ishibashi Yasuyuki
Department of Rehabilitation Medicine, Hirosaki University, Hirosaki, Japan.
Department of Orthopaedic Surgery, Hirosaki University, Hirosaki, Japan.
JSES Int. 2020 Feb 22;4(2):302-309. doi: 10.1016/j.jseint.2019.12.009. eCollection 2020 Jun.
The ball impact position during spiking in volleyball may influence the pattern of activation of shoulder girdle muscles and, therefore, could be a significant risk factor for shoulder injury.
Activation of 10 muscles in the dominant shoulder was evaluated using surface electromyography (EMG) in 11 male volleyball players, during spiking in a static standing position, with the goal being to precisely control the specified ball impact positions, without a run-up or ball setting. The following 4 ball impact positions were evaluated: standard, posterior, medial, and lateral. The EMG amplitude, normalized to the maximal voluntary isometric contraction of the respective muscles, was compared for each phase of the spiking movement between the standard position and the other 3 different impact positions, using the Dunnett test.
The following between-position differences were noted for the deltoid muscle: increased activation of the anterior deltoid during the acceleration phase for the posterior position ( = .041), increase in the posterior deltoid during the acceleration phase for the lateral position ( = .04), and increase in the middle deltoid during the deceleration phase for the lateral position ( = .005).
A posterior or lateral shift in the position of ball impact may cause an increase in the activity of the deltoid muscle that would cause a decrease in the centripetal force of the humeral head through the acceleration and deceleration phases. As such, neuromuscular exercises, combined with strengthening of the rotator cuff muscle, might reduce the risk of shoulder injury during performance of the volleyball spiking movement.
排球扣球时球的撞击位置可能会影响肩带肌的激活模式，因此可能是肩部受伤的一个重要风险因素。
在11名男性排球运动员静态站立扣球过程中，使用表面肌电图（EMG）评估优势肩10块肌肉的激活情况，目的是精确控制特定的球撞击位置，不助跑或传球。评估了以下4个球撞击位置：标准位置、后方位置、内侧位置和外侧位置。使用Dunnett检验比较了标准位置与其他3个不同撞击位置在扣球运动各阶段的EMG幅度（相对于各肌肉的最大自主等长收缩进行标准化）。
三角肌在不同位置间存在以下差异：后方位置在加速阶段前三角肌激活增加（P = 0.041），外侧位置在加速阶段后三角肌增加（P = 0.04），外侧位置在减速阶段中三角肌增加（P = 0.005）。
球撞击位置向后或向外偏移可能会导致三角肌活动增加，这会在加速和减速阶段导致肱骨头向心力下降。因此，神经肌肉训练结合加强肩袖肌力量，可能会降低排球扣球动作中肩部受伤的风险。
