Foot Ankle Int. 2011 Mar;32(3):300-6. doi: 10.3113/FAI.2011.0300.
The moment, a force applied at a distance, is responsible for movement and balance. A key component of the moment is the moment arm. The moment arms of nine muscles surrounding the ankle complex during motion in three planes, were studied.
Five cadaveric feet were mounted in a testing device that created moments in the sagittal, coronal and transverse planes. Axial and tendon loads were applied as the foot was passively moved in these planes. Tendon excursions and bone kinematics were monitored. The moment arm was calculated using the tendon excursion method and averaged across all specimens.
The largest average moment arm during plantarflexion/dorsiflexion, was the Achilles (mean, 53.1; SD, 5.1 mm). During internal/external rotation the largest moment arm was the peroneus brevis (mean, 20.5; SD, 6.4 mm). During inversion/eversion, the largest moment arm was the peroneus longus (31 mm; SD, 2.3 mm).
This study quantified the functional moment arms of nine tendons of the ankle/foot. The involvement of multiple tendons in multiple planes of motion should be considered in computational models and when deciding treatments.
The correlation between moment arms and muscle function has significant effects on treatment efficacy. Information on the balance of moments around the ankle will assist in achieving optimal biomechanical behavior following operative treatments.
力矩是远距离施加的力，负责运动和平衡。力矩的一个关键组成部分是力臂。本研究旨在探讨在三个平面内运动时，踝关节周围九块肌肉的力矩臂。
将五具尸体的脚固定在一个测试装置中，该装置可以在矢状面、冠状面和水平面产生力矩。当脚在这些平面上被动运动时，施加轴向和肌腱负荷。监测肌腱的偏移量和骨骼运动学。使用肌腱偏移量法计算力臂，并对所有标本进行平均。
在跖屈/背屈时，跟腱的平均力矩臂最大（平均为 53.1mm，标准差为 5.1mm）。在内翻/外翻时，腓骨短肌的力矩臂最大（平均为 20.5mm，标准差为 6.4mm）。在外展/内收时，腓骨长肌的力矩臂最大（31mm，标准差为 2.3mm）。
本研究量化了踝关节/足部九根肌腱的功能力矩臂。在计算模型和治疗决策中，应考虑多个肌腱在多个运动平面中的参与。
力矩臂与肌肉功能之间的相关性对治疗效果有显著影响。了解踝关节周围力矩的平衡情况将有助于在手术治疗后实现最佳的生物力学行为。
