Univ Lyon, Université Claude Bernard Lyon 1, Univ Gustave Eiffel, IFSTTAR, LBMC UMR_T9406, F69622, Lyon, France.
Foot & Ankle Institute, Brussels, Belgium.
J Foot Ankle Res. 2020 Mar 12;13(1):13. doi: 10.1186/s13047-020-0381-7.
This study evaluated the 3D angle between the joint moment and the joint angular velocity vectors at the intrinsic foot joints, and investigated if these joints are predominantly driven or stabilized during gait.
The participants were 20 asymptomatic subjects. A four-segment kinetic foot model was used to calculate and estimate intrinsic foot joint moments, powers and angular velocities during gait. 3D angles between the joint moment and the joint angular velocity vectors were calculated for the intrinsic foot joints defined as follows: ankle joint motion described between the foot and the shank for the one-segment foot model (hereafter referred as Ankle), and between the calcaneus and the shank for the multi-segment foot model (hereafter referred as Shank-Calcaneus); joint motion described between calcaneus and midfoot segments (hereafter referred as Chopart joint); joint motion described between midfoot and metatarsus segments (hereafter referred as Lisfranc joint); joint motion described between first phalanx and first metatarsal (hereafter referred as First Metatarso-Phalangeal joint). When the vectors were approximately aligned, the moment was considered to result in propulsion (3D angle <60) or resistance (3D angle >120) at the joint. When the vectors are approximately orthogonal (3D angle close to 90°), the moment was considered to stabilize the joint.
The results showed that the four intrinsic joints of the foot are never fully propelling, resisting or being stabilized, but are instead subject to a combination of stabilization with propulsion or resistance during the majority of the stance phase of gait. However, the results also show that during pre-swing all four the joints are subject to moments that result purely in propulsion. At heel off, the propulsive configuration appears for the Lisfranc joint first at terminal stance, then for the other foot joints at pre-swing in the following order: Ankle, Chopart joint and First Metatarso-Phalangeal joint.
Intrinsic foot joints adopt a stabilized-resistive configuration during the majority of the stance phase, with the exception of pre-swing during which all joints were found to adopt a propulsive configuration. The notion of stabilization, resistance and propulsion should be further investigated in subjects with foot and ankle disorders.
本研究评估了内在足关节处关节力矩与关节角速度向量之间的 3D 夹角，并探讨了这些关节在步态中主要是被驱动还是稳定。
参与者为 20 名无症状受试者。使用四节段动力学足模型来计算和估计步态时内在足关节的关节力矩、功率和角速度。为内在足关节定义了关节力矩与关节角速度向量之间的 3D 夹角，如下所述：单节段足模型中描述的足与小腿之间的关节运动（此后称为踝关节），以及多节段足模型中描述的跟骨与小腿之间的关节运动（此后称为跟-距关节）；跟骨与中足段之间的关节运动（此后称为 Chopart 关节）；中足与跖骨段之间的关节运动（此后称为 Lisfranc 关节）；第一跖骨与第一跖骨之间的关节运动（此后称为第一跖趾关节）。当向量大致对齐时，认为力矩在关节处产生推进力（3D 角度 <60°）或阻力（3D 角度 >120°）。当向量大致正交（3D 角度接近 90°）时，认为力矩稳定关节。
结果表明，足部的四个内在关节从未完全推进、抵抗或稳定，但在步态的大部分支撑相中，它们会受到推进力与阻力稳定的组合作用。然而，结果还表明，在摆动前期，所有四个关节都受到纯粹产生推进力的力矩的作用。在跟离地时，推进构型首先出现在 Lisfranc 关节，然后在摆动前期以下顺序出现在其他足关节：踝关节、Chopart 关节和第一跖趾关节。
内在足关节在大部分支撑相中采用稳定-抵抗构型，摆动前期除外，在摆动前期，所有关节都采用推进构型。在足踝疾病患者中，应进一步研究稳定、抵抗和推进的概念。
