Objectives

Physiological and functional ratios of internal and external rotators are used to assess the muscle balance of shoulder joint. Ratios are usually calculated from the peak torque value (PT) of each muscle group, without taking into account the angular positions at which PT are reached. The aim of our study was to propose an alternative and reliable method based on sectorial analysis for isokinetic assessment of the shoulder muscle balance.

Method

22 men (23.0 ± 2.7y) participated in isokinetic tests of the muscle rotators in a seated position in scapular plane, at 60 °s⁻¹, in concentric (CON) and eccentric (ECC) modes for both shoulders. Peak torque (PT) and torque averaged per range of 10° (T) were calculated for internal and external rotators. Physiological and functional ratios were calculated with classic peak approach (PT-ratios) and new sectorial approach (T-ratios).

Results

PT-ratios and T-ratios were different (P < 0.05). T-ratios were different between the angular ranges (P < 0.05). The reliability was variable as function of angular ranges. The majority of the T-ratios calculated over non-extreme angular ranges were more reliable than PT-ratios (intraclass correlation coefficient=0.14–0.75; coefficient of variation=7.0–28.5%).

Conclusions

The angular range method showed a better reliability than the peak torque method. Angular range method better reflects the functional reality because it takes into account the muscular potential in its entirety of the range of movement.

中文翻译：

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角度范围作为一种可靠的等速方法来评估肩部旋转肌肉。

目标

内、外旋肌的生理和功能比率用于评估肩关节的肌肉平衡。比率通常是根据每个肌肉群的峰值扭矩值 (PT) 计算的，而不考虑达到 PT 的角度位置。我们研究的目的是提出一种基于部门分析的替代且可靠的方法，用于肩部肌肉平衡的等速评估。

方法

22 名男性 (23.0 ± 2.7y) 参加了肩胛平面坐位、60°s ^-1、双肩同心 (CON) 和偏心 (ECC) 模式的肌肉旋转器等速测试。计算内部和外部旋转器的峰值扭矩 (PT) 和每 10° (T) 范围内的平均扭矩。生理和功能比率是用经典峰值方法（PT 比率）和新部门方法（T 比率）计算的。

结果

PT 比率和 T 比率不同（P  < 0.05）。角度范围之间的 T 比不同 ( P  < 0.05)。可靠性作为角度范围的函数是可变的。在非极端角度范围内计算的大多数 T 比比 PT 比更可靠（类内相关系数 = 0.14–0.75；变异系数 = 7.0–28.5%）。

结论

角度范围法比峰值扭矩法表现出更好的可靠性。角度范围法更好地反映了功能现实，因为它考虑了整个运动范围内的肌肉潜力。