The Weak Relationship Between Ankle Proprioception and Gait Speed After Stroke: A Robotic Assessment Study

Background: After stroke, ankle proprioceptive deficits are common and do not typically correlate with ankle weakness. Some studies report that these deficits correlate with gait function, supporting the importance of somatosensory input for gait control. Others have not found a relationship, possibly due to use of coarse proprioception measures. Robotic assessments of proprioception offer improved consistency and sensitivity. Objective: To establish relationships between ankle proprioception, gait function, and ankle motor in stroke survivors. Methods: We studied 39 individuals in the chronic phase of stroke using 2 robotic tests, Crisscross and Joint Position Reproduction (JPR), to quantify ankle proprioception. We examined associations of these measures with gait speed (10-meter walk test) and gait endurance (6-minute walk test). We also analyzed correlations with lower extremity motor impairment, including robotic measures of ankle strength (MVC) and active range of motion (AROM), and the lower extremity Fugl-Meyer exam (LEFM). Results: Impaired ankle proprioception was present in 87% of participants. Crisscross error weakly correlated with the 10mWT gait speed (ρ = −0.20, P = 0.23) and 6MWT distance (ρ = −0.28, P = .089). JPR error weakly correlated with 10mWT gait speed (ρ = −0.29, P = .092) and significantly correlated with 6MWT distance (ρ = −0.34, P = .04). No significant correlations were observed between ankle proprioceptive error and MVC, AROM, or LEFM ( P > 0.2). Conclusion: These results confirm the presence of a weak relationship between ankle proprioception and gait after stroke that is independent of several common measures of motor impairment.