Distinct locomotor adaptation between conventional walking and walking with a walker.

Rolling walkers are common walking aids for individuals with poor physical fitness or balance impairments. There is no doubt that rolling walkers are useful in assisting locomotion. On the other hand, it is arguable that walking with rolling walkers (WW) is effective for maintaining or restoring the nervous systems that are recruited during conventional walking (CW). This is because the differences and similarities of the neural control of these locomotion forms remain unknown. The purpose of the present study was to compare the neural control of WW and CW from the perspective of a split-belt adaptation paradigm and reveal how the adaptations that take place in WW and CW would affect each other. The anterior component of the ground reaction (braking) forces was measured during and after walking on a split-belt treadmill by 10 healthy subjects, and differences in the peak braking forces between the left and right sides were calculated as the index of the split-belt adaptation (the degree of asymmetry). The results demonstrated that (1) WW enabled subjects to respond to the split-belt condition immediately after its start as compared to CW; (2) the asymmetry movement pattern acquired by the split-belt adaptation in one gait mode (i.e., CW or WW) was less transferable to the other gait mode; (3) the asymmetry movement pattern acquired by the split-belt adaptation in CW was not completely washed out by subsequent execution in WW and vice versa. The results suggest unique control of WW and the specificity of neural control between WW and CW; use of the walkers is not necessarily appropriate as training for CW from the perspective of neural control.