Tang Hannah K M, Lake Mark J, Foster Richard J, Bezombes Frederic A
School of Engineering, LJMU, Liverpool, United Kingdom.
Research Institute for Sport and Exercise Sciences, LJMU, Liverpool, United Kingdom.
PLoS One. 2025 Jun 24;20(6):e0324941. doi: 10.1371/journal.pone.0324941. eCollection 2025.
Injuries during quick directional change (cutting) are common, particularly to the anterior cruciate ligament of the knee. Cutting is subsequently a focus in research and clinical practices. However, it is usually assessed in situations with low ecological validity. As a solution, virtual reality (VR) has been used to replicate sporting scenarios. The current paper details the design, development, and piloting of a VR application based on an unanticipated-cutting scenario using an avatar-opponent blocking manoeuvre. The VR environment is highly realistic, avatar approach is instigated by the movement of the headset user, and simple input alters the avatar's movements and spatiotemporal demands of the cutting task. Piloting occurred in two stages: the first involved three participants and focused on initial system testing and parameter optimisation, the second focused on a pilot case study with a female participant of typical population. The case study evaluated the effects of using different visual cutting cues on frontal plane knee kinematics and kinetics linked to injury risk. Twenty-five successful, unanticipated, 90⁰ cutting manoeuvres to the left were analysed in three conditions: 1) physical world with arrows, 2) VR environment emulation with VR arrows, 3) VR environment emulation with VR avatar opponent. Mean knee angle during the arrow conditions, both physical and VR, presented abduction angles (-8.82° ± 1.44; -2.66° ± 0.90), yet cutting around the avatar opponent presented knee adduction angles (9.78° ± 0.44). During the 50 ms prior to heel strike, pelvis velocity was lowest and cutting foot velocity highest in the avatar condition compared to arrow conditions. This indicated the VR environment acts as a suitable control and that cutting strategy was adapted approaching the avatar, displaying more caution on approach. The avatar-based application has the potential to improve the ecological validity of cutting assessment and make a VR application more accessible to researchers and clinicians, with further development.
在快速变向（切入）过程中受伤很常见，尤其是膝关节的前交叉韧带。因此，切入动作随后成为研究和临床实践的重点。然而，它通常在生态效度较低的情况下进行评估。作为一种解决方案，虚拟现实（VR）已被用于模拟体育场景。本文详细介绍了一种基于意外切入场景的VR应用程序的设计、开发和试点，该场景使用了虚拟对手的阻挡动作。VR环境高度逼真，虚拟角色的接近由头戴式设备用户的动作触发，简单的输入可改变虚拟角色的动作以及切入任务的时空要求。试点分两个阶段进行：第一阶段有三名参与者，重点是初始系统测试和参数优化，第二阶段重点是对一名典型人群的女性参与者进行试点案例研究。该案例研究评估了使用不同视觉切入提示对与受伤风险相关的额面膝关节运动学和动力学的影响。在三种情况下分析了25次成功的、意外的向左90°切入动作：1）有箭头的现实世界，2）有VR箭头的VR环境模拟，3）有VR虚拟对手的VR环境模拟。在有箭头的条件下，无论是现实世界还是VR环境，平均膝关节角度均呈现外展角度（-8.82°±1.44；-2.66°±0.90），而在虚拟对手周围切入时呈现膝关节内收角度（9.78°±0.44）。在足跟触地前50毫秒，与箭头条件相比，在虚拟角色条件下骨盆速度最低，切入脚速度最高。这表明VR环境可作为一个合适的对照，并且在接近虚拟角色时切入策略有所调整，接近时表现得更加谨慎。基于虚拟角色的应用程序有潜力提高切入评估的生态效度，并使VR应用程序对研究人员和临床医生更易于使用，有待进一步开发。
