Chronic Pain Influences Lower Extremity Energetics During Landing Cutting in Patients with Chronic Ankle Instability.

CONTEXT: Chronic ankle instability (CAI) patients exhibit altered movement patterns during jump landing/cutting movements. Persistent pain is one of the residual symptoms that may affect movements. Calculating joint energetics affected by chronic pain offers a novel method to understand how chronic pain influences energetics of lower extremity joints in CAI patients. OBJECTIVE: To identify the effects of chronic pain on lower extremity energy dissipation and generation during jump landing and cutting in CAI patients. DESIGN: Cross-sectional Study. SETTING: Laboratory. PATIENTS OR OTHER PARTICIPANTS: Fifteen CAI patients with higher pain (6 males, 9 females; age=22.1±2.1year; height=1.74±0.09m; mass=71.3±10.6kg, pain=66.9±9.4), 15 CAI patients with lower pain (6 males, 9 females; age=22.3±2.1year; height=1.74±0.08m; mass=70.1±10.7kg, pain=89.3±2.6), and 15 healthy controls (6 males, 9 females; age=21.3±1.7year; height=1.73±0.08m; mass=70±10.3kg, pain=100±0). MAIN OUTCOME MEASURES: Ground reaction force data were collected during 5 trials of maximal jump landing/cutting tasks. Joint power was defined as the product of angular velocity and joint moment. Energy dissipation and generation by the ankle, knee, and hip joints were calculated by integrating regions of the joint power curve. RESULTS: CAI patients with higher pain displayed less ankle energy dissipation (p=.013 and p=.018) and generation in the ankle (p=.002 and p=.028) than CAI patients with lower pain and healthy controls during the jump landing/cutting phase. CAI patients with higher pain showed more hip energy generation than CAI patients with lower pain (P=.038) and healthy controls (P=.013) during the cutting phase. CONCLUSIONS: CAI patients with higher pain changed both energy dissipation and generation in the lower extremities, reducing the burden of the ankle joint during jump landing/cutting and having a hip dominant compensatory strategy during the cutting phase. Our results suggest that chronic pain could be one of the factors that affect motor strategies in the CAI population.