In this work, a nonlinear strain rate dependent plugin developed for the OpenSim® platform was used to estimate the instantaneous strain rate (ISR) and the forces on the ACL’s anteromedial (aACL) and posterolateral (pACL) bundles during walking and sudden change of direction of running termed as ‘plant-and-cut’ (PC). The authors obtained the kinematics data for walking via optical motion capture. PC movements, along with running kinematics, were obtained from the literature. A nonlinear plugin developed for ligaments was interfaced with OpenSim® platform to simulate walking and PC motions with a flexed knee and an extended knee. PC phase is sandwiched between an approach phase and take-off phase and was studied at various event velocities (1.8, 3, and 4.2 m s⁻¹), and angles of PC (23°, 34°, and 45°) as encountered in adult ball games. In both cases of PC-with-extended knee and PC-with-flexed-knee, the maximum forces on both the ACL bundles were observed after the take-off phase. A maximum force of ~ 35 N kg⁻¹ of body weight (BW) was observed on aACL after the take-off phase for an event velocity of 4.2 m s⁻¹. In the posterolateral bundle (pACL), the maximum forces (~ 40 N kg⁻¹ of BW) were observed towards the end of the mid-swing phase (after the take-off phase) for the various combinations of the parameters studied. The forces observed in the simulation of PC-with-flexed-knee and PC-with-extended-knee has resulted in magnitude higher than sustainable by the adults. This study is novel in attempting to incorporate differing rates-of-strain that have been shown to alter soft tissue properties into the OpenSim® musculoskeletal model. The proposed model can be used by researchers to predict the forces during various kinematic activities for other soft tissues.

在这项工作中，使用为 OpenSim® 平台开发的非线性应变率依赖插件来估计瞬时应变率 (ISR) 以及在行走和突然改变方向期间 ACL 前内侧 (aACL) 和后外侧 (pACL) 束上的力运行被称为“种植和切割”（PC）。作者通过光学运动捕捉获得了行走的运动学数据。PC运动以及跑步运动学是从文献中获得的。为韧带开发的非线性插件与 OpenSim® 平台连接，以模拟弯曲膝盖和伸展膝盖的行走和PC运动。个人电脑阶段夹在进场阶段和起飞阶段之间，并在成人遇到的各种事件速度（1.8、3 和 4.2 m s ^-1）和PC角度（23 °、34 °和 45 °）下进行了研究球赛。在这两种情况下PC-与扩展膝盖和PC与-弯曲膝盖，进行起飞阶段之后观察到对ACL束两者的最大的力。的〜35 N kg的最大力^-1上AACL观察起飞阶段为4.2米每秒的事件后速度体重（BW）^-1。在后外侧束 (pACL) 中，最大力 (~ 40 N kg ^-1对于所研究的参数的各种组合，在中摆阶段（起飞阶段之后）结束时观察到 BW 的变化。在膝关节屈曲和膝关节伸直的 PC 模拟中观察到的力导致的幅度高于成年人的承受能力。这项研究的新颖之处在于尝试将不同的应变率合并到 OpenSim® 肌肉骨骼模型中，这些应变率已被证明会改变软组织特性。研究人员可以使用所提出的模型来预测其他软组织在各种运动活动期间的力。