Altered Movement Neuromechanics during Jump Landing and Cutting in Patients with Chronic Ankle Instability

Abstract

Lateral ankle sprains are common lower extremity injury during sport activities, which often lead to chronic ankle instability (CAI). However, no one has comprehensively examined the effects of CAI on lower extremity movement neuromechanics during a multiplanar, single-leg landing and cutting task for CAI patients. PURPOSE: To investigate the effect of CAI on landing and cutting lower-extremity kinematic, electromyography (EMG), and ground reaction force (GRF). METHODS: 100 CAI patients (22±2 yrs, 174±10 cm, 71±14 kg, 82±9% FAAM ADL, 62±13% FAAM Sports, 4.5±2.6 ankle sprains) and 100 controls (22±3 yrs, 172±13 cm, 72±18 kg, 100% FAAM ADL & Sports) participated. Participants performed five successful trials of a jump landing and cutting task. Sagittal and frontal planes of ankle, knee and hip joint angles, EMG activation, and GRF were collected during jump landing and cutting. Functional analyses of variance (FANOVA) were used to evaluate between-group differences for these dependent variables throughout the entire ground contact phase of the task. RESULTS: Figure 1. Relative to the control group, the CAI group revealed (i) reduced dorsiflexion and hip flexion angles, (ii) increased inversion and reduced hip abduction angles, (iii) increased posterior and vertical GRF during initial landing, and reduced posterior and vertical GRF, and (iv) increased EMG activation of peroneus longus, and gluteus medius during mid-landing and cutting phase. CONCLUSION: Our data suggest that CAI patients demonstrated different movement strategies during jump landing and cutting. Compared to controls, patients with CAI utilized the proximal (hip) joint with heightened corresponding muscle activation to compensate for a potentially unstable distal (ankle) joint (e.g., more inversion and less dorsiflexion angle) in an attempt to reduce ground impact force. This apparent compensation may be due to sensorimotor deficits in the ankle.Figure