Effects Of Persistent Pain On Kinematics During Walking In Individuals With Chronic Ankle Instability

A majority of people who suffer lateral ankle sprains develop chronic ankle instability (CAI) with persistent pain being one of the residual symptoms. However, little is known about how persistent pain affects kinematics during walking in individuals with CAI. Purpose: To identify the effects of persistent pain on joint angles during walking in CAI patients. Methods: This study was a cross-sectional study. Twenty high pain individuals with CAI (High pain), 20 low pain individuals with CAI (Low pain), and 20 healthy controls (Control). We adhere to the guidelines provided by the International Ankle Consortium and Foot and Ankle Outcome Scores for classifying CAI and chronic pain. We used 44 reflective markers to calculate joint angles during walking from initial contact to toe-off (0-100% of stance). Functional analyses of variance were used to assess between-group differences for kinematics outcomes. Results: Both the high and low pain demonstrated altered joint angles compared to the control. In the sagittal plane, the high pain showed up to 1.6° and 2.8° more ankle dorsiflexion and 2.9° and 1.7° more knee flexion than the low pain and control. The low pain exhibited up to 1.7° more ankle plantarflexion and 1.7° less knee flexion than the control. In the frontal plane, both the high and low pain showed 2.1° or 3° more inversion than the control. The high pain showed up to 1° less ankle inversion than the low pain. Conclusion: Persistent pain affects altered joint kinematics in individuals with CAI. In the sagittal plane, the high pain demonstrated a stiff ankle which may establish a stable ankle position and revealed a proximal-dominant strategy which may compensate for reduced ability of impact force absorbing in the ankle during walking.