The purpose of this study investigated which biofeedback (BF) training enables efficient activation of the infraspinatus muscle that affect joint position sense (JPS) and force sense (FS) of the shoulder joint. Twenty healthy males participated and performed three external rotation (ER) exercises under three randomly assigned training conditions: 1) non-biofeedback (NBF), 2) BF and 3) force biofeedback (FBF). Each exercise was performed at intervals of one week between training conditions. After performed the ER exercise under each training condition, the relative error (RE) was calculated at shoulder ER 45° and 80°, and then shoulder ER force were measured to determine the JPS error and FS error, respectively. Muscle activity of infraspinatus and posterior deltoid were measured and compared between training conditions. The RE of shoulder ER 45° and 80° were significantly lower under the FBF conditions than other training conditions (P < 0.05). The RE of shoulder ER force were also significantly lower under the FBF conditions compared to those under the other training conditions (P < 0.05). The activity of the infraspinatus muscle was significantly higher under the FBF conditions during all three ER exercises than other training conditions (p < 0.05). We suggest that BF trainings can be useful to improve the proprioception of shoulder joint as well as activation of infraspinatus muscle while performing the ER exercises.

本研究的目的是调查哪种生物反馈（BF）训练能够有效激活冈下肌，从而影响肩关节的关节位置感（JPS）和力感（FS）。20 名健康男性参与并在三种随机分配的训练条件下进行了 3 次外旋 (ER) 练习：1) 非生物反馈 (NBF)、2) BF 和 3) 力生物反馈 (FBF)。每次练习在训练条件之间间隔一周进行。在每种训练条件下进行ER练习后，计算肩部ER 45°和80°处的相对误差（RE），然后测量肩部ER力，分别确定JPS误差和FS误差。测量并比较训练条件下冈下肌和三角肌后束的肌肉活动。FBF条件下肩部ER 45°和80°的RE显着低于其他训练条件（ P  < 0.05）。FBF 条件下肩部 ER 力的 RE 也显着低于其他训练条件下（P  < 0.05）。在所有三种 ER 练习期间，冈下肌的活动在 FBF 条件下均显着高于其他训练条件 ( p  < 0.05)。我们建议，BF 训练有助于改善肩关节的本体感觉以及在进行 ER 练习时激活冈下肌。