School of Exercise and Health, Shanghai University of Sport, Shanghai, China.
School of Exercise and Health, Shanghai University of Sport, Shanghai, China; Key Laboratory of Exercise and Health Sciences of Ministry of Education, Shanghai University of Sport, Shanghai, China.
Gait Posture. 2024 May;110:122-128. doi: 10.1016/j.gaitpost.2024.03.008. Epub 2024 Mar 12.
Landing from heights is a common movement for active-duty military personnel during training. And the additional load they carry while performing these tasks can affect the kinetics and ankle kinematic of the landing. Traditional motion capture techniques are limited in accurately capturing the in vivo kinematics of the talus. This study aims to investigate the effect of additional trunk load on the kinematics of the talocrural and subtalar joints during landing, using a dual fluoroscopic imaging system (DFIS).
Fourteen healthy male participants were recruited. Magnetic resonance imaging was performed on the right ankle of each participant to create three-dimensional (3D) models of the talus, tibia, and calcaneus. High-speed DFIS was used to capture the images of participants performing single-leg landing jumps from a height of 40 cm. A weighted vest was used to apply additional load, with a weight of 16 kg. Fluoroscopic images were acquired with or without additional loading condition. Kinematic data were obtained by importing the DFIS data and the 3D models in virtual environment software for 2D-3D registration. The kinematics and kinetics were compared between with or without additional loading conditions.
During added trunk loading condition, the medial-lateral translation range of motion (ROM) at the talocrural joint significantly increased (p < 0.05). The subtalar joint showed more extension at 44-56 ms (p < 0.05) after contact. The subtalar joint was more eversion at 40-48 ms (p < 0.05) after contact under the added trunk load condition. The peak vertical ground reaction force (vGRF) significantly increased (p < 0.05).
With the added trunk load, there is a significant increase in peak vGRF during landing. The medial-lateral translation ROM of the talocrural joint increases. And the kinematics of the subtalar joint are affected. The observed biomechanical changes may be associated with the high incidence of stress fractures in training with added load.
高处着陆是现役军人在训练中常见的动作。而他们在执行这些任务时所携带的额外负荷会影响着陆时的动力学和踝关节运动学。传统的运动捕捉技术在准确捕捉距骨的体内运动学方面存在局限性。本研究旨在使用双荧光透视成像系统（DFIS）研究额外的躯干负荷对距小腿关节和距下关节在着陆时的运动学的影响。
招募了 14 名健康的男性参与者。对每位参与者的右踝关节进行磁共振成像，以创建距骨、胫骨和跟骨的三维（3D）模型。使用高速 DFIS 捕获参与者从 40cm 高处进行单腿着陆跳跃的图像。使用加重背心施加额外的负荷，重量为 16kg。在有或没有额外加载条件下获取荧光透视图像。通过将 DFIS 数据和 3D 模型导入虚拟环境软件进行 2D-3D 配准，获得运动学数据。比较有或没有额外加载条件下的运动学和动力学。
在附加躯干负荷条件下，距小腿关节的内外侧平移运动范围（ROM）明显增加（p < 0.05）。在接触后 44-56ms 时，距下关节的伸展度更大（p < 0.05）。在附加躯干负荷条件下，距下关节在接触后 40-48ms 时的外旋角度更大（p < 0.05）。垂直地面反作用力峰值（vGRF）显著增加（p < 0.05）。
在附加躯干负荷下，着陆时 vGRF 的峰值显著增加。距小腿关节的内外侧平移 ROM 增加。并且距下关节的运动学受到影响。观察到的生物力学变化可能与训练中附加负荷导致的高应力性骨折发生率有关。
