Krishnan Chandramouli, Ranganathan Rajiv, Tetarbe Manik
Department of Physical Medicine and Rehabilitation, University of Michigan Medical School, Ann Arbor, MI, USA.
Department of Kinesiology, Michigan State University, East Lansing, MI, USA.
Gait Posture. 2017 Jul;56:24-30. doi: 10.1016/j.gaitpost.2017.04.032. Epub 2017 Apr 27.
Several studies have shown that learning a motor skill in one limb can transfer to the opposite limb-a phenomenon called as interlimb transfer. The transfer of motor skills between limbs, however, has shown to be asymmetric, where one side benefits to a greater extent than the other. While this phenomenon has been well-documented in the upper-extremity, evidence for interlimb transfer in the lower-extremity is limited and mixed. This study investigated the extent of interlimb transfer during walking, and tested whether this transfer was asymmetric using a foot trajectory-tracking paradigm that has been specifically used for gait rehabilitation. The paradigm involved learning a new gait pattern which required greater hip and knee flexion during the swing phase of the gait while walking on a treadmill. Twenty young adults were randomized into two equal groups, where one group (right-to-left: RL) practiced the task initially with the dominant right leg and the other group (left-to-right: LR) practiced the task initially with their non-dominant left leg. After training, both groups practiced the task with their opposite leg to test the transfer effects. The changes in tracking error on each leg were computed to quantify learning and transfer effects. The results indicated that practice with one leg improved the motor performance of the other leg; however, the amount of transfer was similar across groups, indicating that there was no asymmetry in transfer. This finding is contradictory to most upper-extremity studies (where asymmetric transfer has been reported) and points out that both differences in neural processes and types of tasks may mediate interlimb transfer.
多项研究表明，在一侧肢体学习运动技能可转移至对侧肢体——这一现象称为肢体间转移。然而，肢体间运动技能的转移已显示出不对称性，即一侧受益程度大于另一侧。虽然这一现象在上肢已有充分记录，但下肢肢体间转移的证据有限且存在矛盾。本研究调查了步行过程中肢体间转移的程度，并使用专门用于步态康复的足部轨迹跟踪范式测试这种转移是否不对称。该范式包括学习一种新的步态模式，即在跑步机上行走时，在步态摆动期需要更大程度的髋部和膝部屈曲。20名年轻成年人被随机分为两组，一组（从右到左：RL）最初用优势右腿练习任务，另一组（从左到右：LR）最初用非优势左腿练习任务。训练后，两组都用对侧腿练习任务以测试转移效果。计算每条腿跟踪误差的变化以量化学习和转移效果。结果表明，用一条腿练习可提高另一条腿的运动表现；然而，各组间的转移量相似，表明转移不存在不对称性。这一发现与大多数上肢研究（其中报告了不对称转移）相矛盾，并指出神经过程和任务类型的差异可能都介导了肢体间转移。
