Acquisition of a precision walking skill and the impact of proprioceptive deficits in people with motor-incomplete spinal cord injury

Many people with motor-incomplete spinal cord injury (m-iSCI) experience difficulty navigating obstacles, such as curbs and stairs. The ability to relearn walking skills may be limited by proprioceptive deficits. The purpose of this study was to determine the capacity of participants to acquire a precision walking skill, and to evaluate the influence of proprioceptive deficits on the skill acquisition in individuals with m-iSCI. Sixteen individuals with m-iSCI and eight controls performed a precision walking task that required matching their foot height to a target during the swing phase. Proprioceptive deficits were quantified at the hip and knee for joint position and movement detection sense. Participants completed 600 steps of training with visual feedback. Pretraining and posttraining tests were conducted without visual feedback, along with a transfer test with an ankle weight. Posttraining and transfer tests were repeated 1 day later. Participants returned to the laboratory 1 wk later to repeat the training. Performance was calculated as the vertical distance between the target and actual foot height for each step. The posttraining and transfer performances were similar between groups. However, participants with m-iSCI had a slower rate of acquisition to achieve a similar performance level compared with controls. Acquisition rate and posttraining performance of the precision walking task were related to lower limb joint position sense among SCI participants. Although they can achieve a similar level of performance in a precision walking task, proprioceptive deficits impair the rate of learning among individuals with m-iSCI compared with able-bodied controls. NEW & NOTEWORTHY People with motor-incomplete spinal cord injuries are able to achieve the same level of performance accuracy on a precision walking task as able-bodied controls; however, the rate of learning is slower, indicating that more practice is required to stabilize performance. Our findings also show a relationship between impaired sensory function and reduced accuracy when performing a precision walking task after spinal cord injury.