Sasaki Shuichi, Kenmoku Tomonori, Otera Ayumi, Miyajima Genyo, Nagura Naoshige, Nakawaki Mitsufumi, Nakazawa Toshiyuki, Takaso Masashi, Fukuda Michinari, Takahira Naonobu
Department of Rehabilitation, Kitasato University East Hospital, Sagamihara, Japan.
Department of Orthopedic Surgery, Kitasato University School of Medicine, Sagamihara, Japan.
J Orthop Sci. 2019 Jan;24(1):75-80. doi: 10.1016/j.jos.2018.04.010. Epub 2018 Sep 6.
Strengthening the infraspinatus is important in shoulder rehabilitation. Changes in infraspinatus activity with changing load and position have not been quantified. We sought to determine the most appropriate load and posture for early infraspinatus strengthening by assessing for changes in electromyographic activity in the healthy infraspinatus and other shoulder girdle muscles during isometric external rotational exercise under different loads with the shoulder adducted in the supine and seated positions.
Sixteen healthy adults (30 shoulders) performed isometric shoulder external rotation in the sitting and supine positions, starting with the shoulder and forearm in neutral position and the elbow flexed 90°. Loads (0.5 kg, 1 kg, and 2 kg) were applied at rest. We assessed the infraspinatus, upper trapezius, posterior deltoid, and biceps brachii. For analysis, we used the mean percentage of maximum voluntary muscle contraction (%MVC) value measured during each isometric contraction divided by the maximum voluntary muscle contraction (MVC) of each muscle.
In the infraspinatus and posterior deltoid, significant interaction was observed between body position and load. Compared to the sitting position, an increase in activity in the supine position was attenuated as load increased, especially at 2 kg. The supine values of the upper trapezius and biceps brachii were always significantly lower than those in the sitting position regardless of load.
The activity of the infraspinatus can be increased gradually during rehabilitation by beginning in the supine position, which assures low activity of the upper trapezius and biceps brachii. Exercise with the shoulder adducted in the supine position can strengthen the infraspinatus gradually and avoid compensatory mobility.
Level 3.
在肩部康复中，加强冈下肌力量很重要。随着负荷和体位变化，冈下肌活动的改变尚未被量化。我们试图通过评估在仰卧位和坐位内收肩部时，不同负荷下等长外旋运动期间健康冈下肌和其他肩带肌的肌电图活动变化，来确定早期加强冈下肌力量的最合适负荷和姿势。
16名健康成年人（30个肩部）在坐位和仰卧位进行等长肩部外旋，起始时肩部和前臂处于中立位，肘部屈曲90°。在休息时施加负荷（0.5千克、1千克和2千克）。我们评估了冈下肌、上斜方肌、后三角肌和肱二头肌。分析时，我们使用每次等长收缩期间测量的最大自主肌肉收缩百分比（%MVC）值除以每块肌肉的最大自主肌肉收缩（MVC）。
在冈下肌和后三角肌中，观察到体位和负荷之间存在显著交互作用。与坐位相比，随着负荷增加，仰卧位时的活动增加减弱，尤其是在2千克时。无论负荷如何，上斜方肌和肱二头肌的仰卧位值始终显著低于坐位值。
在康复过程中，通过从仰卧位开始，可以逐渐增加冈下肌的活动，这可确保上斜方肌和肱二头肌的低活动水平。在仰卧位内收肩部进行锻炼可逐渐增强冈下肌力量并避免代偿性活动。
3级。
