Proprioception of the Ankle is Impaired in People with Parkinson’s Disease

Background: Proprioception has not been examined in the lower limb in people with Parkinson's disease (PD). Impaired proprioception may contribute to activity limitations, including falls in individuals with PD. Objectives: The aims of this study were to determine whether: (1) people with PD have impaired proprioception in the ankles during active movements; (2) there are correlations between ankle proprioception and history of falls, fear of falling, and parkinsonian symptoms. Methods: This was a cross-sectional observational study of ankle proprioception in people with mild to moderate PD and healthy age-matched controls. Included in the study were thirteen participants with mild to moderate PD, aged 71 SD (31) years, and 14 age-matched controls, aged 66 SD (21) years. Proprioception of the ankle was measured using the Active Movement Extent Discrimination Apparatus. Symptom severity was measured using the PDQ-39. Fear of falling was measured using the Falls Efficacy Scale, and participants were questioned about their history of falls during the previous 12 months. All measures were completed on one occasion. Results: People with PD had significantly worse proprioception in plantarflexion (mean difference 0.045, 95% CI 0.00 to 0.09), inversion (mean difference 0.059, 95% CI 0.02 to 0.10), and overall proprioception (mean difference 0.048, 95% CI 0.00 to 0.10) than control participants. In people with PD, there was a significant moderate negative correlation between impaired proprioception and Parkinson's symptoms (r = −0.441, P = 0.021). Conclusions: Impaired proprioception of the ankle is evident in people with PD. Further research is warranted to determine whether proprioception can be improved in people with PD.