Locomotion Physiomechanics Laboratory, Department of Pathophysiology and Transplantation - Division of Physiology, University of Milan, Via Mangiagalli 32, 20133, Milan, Italy.
Eur J Appl Physiol. 2024 Mar;124(3):783-792. doi: 10.1007/s00421-023-05306-0. Epub 2023 Sep 30.
The purpose of this study was to investigate the metabolic cost (C), mechanical work, and kinematics of walking on a multidirectional treadmill designed for locomotion in virtual reality.
Ten participants (5 females, body mass 67.2 ± 8.1 kg, height 1.71 ± 0.07 m, age 23.6 ± 1.9 years, mean ± SD) walked on a Virtuix Omni multidirectional treadmill at four imposed stride frequencies: 0.70, 0.85, 1.00, and 1.15 Hz. A portable metabolic system measured oxygen uptake, enabling calculation of C and the metabolic equivalent of task (MET). Gait kinematics and external, internal, and total mechanical work (W) were calculated by an optoelectronic system. Efficiency was calculated either as W/C or by summing W to the work against sliding frictions. Results were compared with normal walking, running, and skipping.
C was higher for walking on the multidirectional treadmill than for normal walking, running, and skipping, and decreased with speed (best-fit equation: C = 20.2-27.5·speed + 15.8·speed); the average MET was 4.6 ± 1.4. Mechanical work was higher at lower speeds, but similar to that of normal walking at higher speeds, with lower pendular energy recovery and efficiency; differences in efficiency were explained by the additional work against sliding frictions. At paired speeds, participants showed a more forward-leaned trunk and higher ankle dorsiflexion, stride frequency, and duty factor than normal walking.
Walking on a multidirectional treadmill requires a higher metabolic cost and different mechanical work and kinematics than normal walking. This raises questions on its use for gait rehabilitation but highlights its potential for high-intensity exercise and physical activity promotion.
本研究旨在探讨为虚拟现实环境下的运动而设计的多向跑步机上行走的代谢成本（C）、机械功和运动学。
10 名参与者（5 名女性，体重 67.2±8.1kg，身高 1.71±0.07m，年龄 23.6±1.9 岁，平均值±标准差）在 Virtuix Omni 多向跑步机上以 4 种规定的步频行走：0.70、0.85、1.00 和 1.15Hz。便携式代谢系统测量耗氧量，从而计算 C 和任务代谢当量（MET）。通过光电系统计算步态运动学以及外部、内部和总机械功（W）。效率可以通过 W/C 计算，也可以通过将 W 与滑动摩擦力的功相加来计算。结果与正常行走、跑步和跳绳进行比较。
与正常行走、跑步和跳绳相比，在多向跑步机上行走的 C 更高，且随速度降低（最佳拟合方程：C=20.2-27.5·速度+15.8·速度）；平均 MET 为 4.6±1.4。机械功在较低速度下较高，但在较高速度下与正常行走相似，摆动能量回收和效率较低；效率差异由对抗滑动摩擦力的额外功解释。在配对速度下，与正常行走相比，参与者的躯干前倾角度更大，踝关节背屈、步频和作用时间比更高。
在多向跑步机上行走比正常行走需要更高的代谢成本和不同的机械功和运动学。这对其在步态康复中的应用提出了质疑，但强调了其在高强度运动和促进身体活动方面的潜力。
