Proprioception After Unilateral Stroke: Changes in the Affected and Unaffected Lower Limbs Over Time

BACKGROUND: Proprioceptive deficits are common among stroke survivors and can negatively impact their balance and postural control. However, there has been little evaluation of the change in proprioceptive deficits in the lower limbs over time after stroke. This study aimed to examine proprioceptive deficits over time after stroke in both the affected and "unaffected" lower limbs. METHODS: This cross-sectional study included sixty first-time unilateral stroke survivors and twenty age-matched healthy individuals. Participants after stroke were divided into three subgroups based on different time points after stroke. The generally accepted clinical time points after stroke are the first 4 weeks-the acute stage; 5-24 weeks-the subacute stage; over 24 weeks-the chronic stage. The active movement extent discrimination apparatus (AMEDA) was used to quantify ankle proprioception in plantarflexion and inversion directions, on both the affected and "unaffected" sides. RESULTS: Lower limb proprioception scores decreased linearly over time after stroke on both the affected and "unaffected" sides (p < 0.001). Overall, proprioception scores for the stroke groups were significantly lower than those for the healthy age-matched group (p < 0.01), with the only exception being ankle plantarflexion and inversion scores on the unaffected side in the acute stroke group, which were not significantly different from their healthy counterparts. CONCLUSION: Ankle proprioception in both lower limbs decreased over time after a unilateral stroke, with proprioceptive acuity on the "unaffected" side diminishing linearly in the same way as that on the affected side. These observed continuing deficits in lower limb proprioception among stroke survivors raise implications for clinical neurorehabilitation.