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

Abstract

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.

Ankle proprioception during gait in individuals with incomplete spinal cord injury

“…In addition, recent studies show that (a) proprioceptive impairment affects the rate of learning a precision walking task (Chisholm, Qaiser, Williams, Eginyan, & Lam, 2019) and (b) the magnitude of improvement after gait training is related to pretraining proprioceptive sense (Qaiser, Eginyan, Chan, & Lam, 2019). The protocol developed in the present study could therefore also be used as a baseline assessment tool to potentially predict therapy outcome and help in patient screening.…”

The sensorimotor effects of a lower limb proprioception training intervention in individuals with a spinal cord injury

“…Body support was provided as needed to ensure proper stance-phase kinematics during treadmill walking (i.e., appropriate hip and knee extension during midstance, without buckling). The protocol for this task has been described in detail in our previous work (Chisholm et al 2019;Qaiser et al 2016). Briefly, the goal of the task was to match peak foot trajectory height in the swing phase to the height of a virtual target displayed on a monitor.…”

“…This was done to determine the target height above Norm height that was 25% of the range between Max and Norm and followed previous protocols to provide a challenging walking task that was within the limits of each participant's ability (Chisholm et al 2019;Malik et al 2017;Qaiser et al 2016).…”

“…Small changes at individual joints can account for adaptations in foot clearance to successfully navigate these tasks. Previous studies have indicated a role of proprioceptive sense for precision control of foot trajectory during walking (Chisholm et al 2019;Qaiser et al 2016;van Hedel et al 2005). For example, able-bodied individuals can learn a precision-stepping obstacle-clearance task without any visual input, implicating the importance of lower limb proprioception in acquiring this skill (Erni and Dietz 2001;Lam and Dietz 2004;van Hedel et al 2002).…”

“…We hypothesized that our training protocol not only could result in improved end-point (foot) position sense but also would transfer to improved joint position sense. Evidence from previous studies has also indicated lower limb proprioceptive sense is linked to the ability to precisely control foot trajectory during walking (Chisholm et al 2019;Malik et al 2017;Qaiser et al 2016). As such, a secondary aim was to assess whether passive proprioception training would transfer to performance in a precision stepping task in people with motor-incomplete SCI.…”