Stroke and ageing are common causes for proprioceptive impairments. Such impairments may contribute to disabilities in daily living activities, such as walking. Yet, current rehabilitation methods mainly focus on motor disabilities, and often neglect somatosensory impairments. Moreover, clinical methods for proprioception assessment of both the upper and lower limb are subjective and suffer from inconsistency between evaluators, and the majority of the research in quantitative assessment of proprioception focuses on the upper limb. To address these gaps, we present a novel tool for quantitative assessment of proprioception of the lower limb.
We developed a tool that consists of a magnetic tracking system with magnetic sensors placed on the participants’ toes while the participants were laying on their side. We designed an assessment protocol that includes contralateral position matching tests and ipsilateral position matching tests, and applied them to both lower limbs (N: non-dominant and D: dominant). We validated the tool on three groups of participants: young adults (n=18), elderly (n=8), and stroke survivors (n=5) by comparing the results of the mean absolute error (MAE), bias and the mean variable error (MVE).
We evaluated the effect of group type, proprioceptive input, task type and their interactions. We compared between young adults and elderly with statistical analysis, and demonstrated the results of the stroke survivors. We found significant differences in MAE and bias between the elderly and young adults in the contralateral tasks, particularly once spatial information is transmitted from the N limb to the D limb, indicating that the ability to transit spatial information contralaterally becomes more challenging with age. The bias also indicated that the contralateral task is more challenging with the groups, independently.
Using contralateral position matching may be an effective way to identify potential somatosensory impairments. In order to avoid a long and unnecessary assessment, we suggested using contralateral position matching as a screening phase in identifying lower limb proprioceptive impairments, followed by ipsilateral position matching only for individuals with impaired results for identifying possible confounds from motor and cognitive impairments.