Sensorimotor incongruence during walking using delayed visual feedback.

The ability to detect small errors between sensory prediction in the brain and actual sensory feedback is important in rehabilitation after brain injury, where motor function needs to be restored. To date in the recent study, a delayed visual error detection task during upper limb movement was used to measure this ability for healthy participants or patients. However, this ability during walking, which is the most sought-after in brain-injured patients, was unclear. The main purpose of this study was to investigate the effects of walking parameters, the sense of body heaviness, and delayed error detection rate in a visual feedback delay experiment during treadmill walking for healthy participants. It was also unclear how sagittal or frontal feedback during walking, which is commonly used clinically, affects the error detection task. Therefore, another purpose of the study was to investigate whether each outcome was modulated by different observation viewpoints. We found that walking parameters (step time and stride time), sense of body heaviness, and incongruence detection rate were increasing with delay time and that these data did not depend on the observation viewpoints. In the future, this study will provide an important cue to develop the methods that assess the sensory-motor integration function of patients during walking.