Department of Orthopaedic Surgery, University of Pittsburgh, USA.
J Biomech. 2010 Sep 17;43(13):2618-24. doi: 10.1016/j.jbiomech.2010.05.003.
Previous deterministic finger biomechanical models predicted that the flexor digitorum superficialis (FDS) was silent and the flexor digitorum profundus (FDP) was the only active flexor during finger flexion. Experimental studies in vivo, however, recorded activities of both flexors. In this study, in an attempt to elucidate the roles of the flexors, a probabilistic biodynamic model of the index finger was constructed to estimate the muscle-tendon forces during an experimentally measured index finger flexion movement. A Monte-Carlo simulation was performed with four model parameters, including moment arms, physiological cross sectional areas (PCSA), passive torques, and anthropometric measures as independent random variables. The muscle-tendon forces at each time point were determined using a nonlinear optimization technique. The model predicted that both FDS and FDP contributed to sustaining the movement and the FDS was not necessarily silent. The two distinct force patterns observed in vivo in experimental studies were also corroborated by the simulation. These findings, contrary to previous deterministic models' predictions but in agreement with experimental measurements, explained the observed coactivation of FDS and FDP, and resolved the controversy regarding the roles of the flexors in finger movement dynamics.
先前的确定性手指生物力学模型预测，屈指浅肌（FDS）是静止的，而屈指深肌（FDP）是手指弯曲时唯一活跃的屈肌。然而，体内的实验研究记录了这两块屈肌的活动。在这项研究中，为了阐明屈肌的作用，构建了食指的概率生物动力学模型，以估计在实验测量的食指弯曲运动过程中肌肉-肌腱的力。通过蒙特卡罗模拟，以臂长、生理横截面积（PCSA）、被动扭矩和人体测量学指标作为独立的随机变量，对四个模型参数进行了分析。使用非线性优化技术确定了每个时间点的肌肉-肌腱力。模型预测，FDS 和 FDP 都有助于维持运动，而且 FDS 不一定是静止的。该模拟还证实了在体内实验研究中观察到的两种截然不同的力模式。这些发现与先前的确定性模型的预测相反，但与实验测量结果一致，解释了 FDS 和 FDP 的观察到的共同激活现象，并解决了关于屈肌在手指运动动力学中的作用的争议。
