Individuals with chronic ankle instability exhibit altered ankle kinematics and neuromuscular control compared to copers during inversion single-leg landing.

Abstract

OBJECTIVES\nThis study compares the ankle kinematics and muscle activities of the individuals with chronic ankle instability (CAI), coper, and control groups in normal and inversion single-leg landings.\n\n\nDESIGN\ncross-sectional study; SETTING: Biomechanics laboratory.\n\n\nPARTICIPANTS\nPhysically active adults with CAI (N\xa0=\xa012); and coper (N\xa0=\xa012) and control (N\xa0=\xa012) groups.\n\n\nMAIN OUTCOME MEASURES\nThe participants performed normal and inversion single-leg landing. The muscle activity 200\xa0ms before and after landing of the tibialis anterior, the medial gastrocnemius, and the fibularis longus (FL) were recorded. The FL latency, sagittal and frontal co-contraction indexes (CCI), ankle inversion angle at the initial contact, and the maximum inversion angle were recorded.\n\n\nRESULTS\nSignificantly longer FL latency, decreased FL muscle activity, frontal CCI, and an increased maximum inversion angle at post-landing were discovered during inversion single-leg landing in the CAI group compared to the coper and control groups. However, no significant difference was observed among the CAI and coper groups during normal single-leg landing.\n\n\nCONCLUSION\nThese results suggest prolonged FL latency and altered ankle kinematics suggest an increased risk of recurrent lateral ankle sprains in CAI with inversion single-leg landing.