Gregory Daniel L, Sup Frank C, Choi Julia T
Department of Kinesiology, University of Massachusetts Amherst, Amherst, MA, USA.
Department of Mechanical and Industrial Engineering, University of Massachusetts Amherst, Amherst, MA, USA.
R Soc Open Sci. 2021 Feb 10;8(2):202084. doi: 10.1098/rsos.202084.
Walking requires control of where and when to step for stable interlimb coordination. Motorized split-belt treadmills which constrain each leg to move at different speeds lead to adaptive changes to limb coordination that result in after-effects (e.g. gait asymmetry) on return to normal treadmill walking. These after-effects indicate an underlying neural adaptation. Here, we assessed the transfer of motorized split-belt treadmill adaptations with a custom non-motorized split-belt treadmill where each belt can be self-propelled at different speeds. Transfer was indicated by the presence of after-effects in step length, foot placement and step timing differences. Ten healthy participants adapted on a motorized split-belt treadmill (2 : 1 speed ratio) and were then assessed for after-effects during subsequent non-motorized treadmill and motorized tied-belt treadmill walking. We found that after-effects in step length difference during transfer to non-motorized split-belt walking were primarily associated with step time differences. Conversely, residual after-effects during motorized tied-belt walking following transfer were associated with foot placement differences. Our data demonstrate decoupling of adapted spatial and temporal locomotor control during transfer to a novel context, suggesting that foot placement and step timing control can be independently modulated during walking.
行走需要控制迈步的位置和时间，以实现稳定的肢体间协调。电动分体式跑步机通过限制双腿以不同速度移动，会导致肢体协调的适应性变化，进而在恢复正常跑步机行走时产生后效应（如步态不对称）。这些后效应表明存在潜在的神经适应性。在此，我们使用定制的非电动分体式跑步机评估电动分体式跑步机适应性的迁移情况，该跑步机的每条皮带可自行以不同速度驱动。步长、足部位置和步时差异中的后效应表明了迁移的存在。十名健康参与者在电动分体式跑步机（速度比为2:1）上进行适应性训练，随后在后续的非电动跑步机和电动捆绑式跑步机行走过程中评估后效应。我们发现，在转移到非电动分体式行走过程中，步长差异的后效应主要与步时差异相关。相反，转移后在电动捆绑式行走过程中的残余后效应与足部位置差异相关。我们的数据表明，在转移到新情境时，适应性空间和时间运动控制出现了解耦，这表明在行走过程中足部位置和步时控制可以独立调节。
