Ankle laxity affects ankle kinematics during a side-cutting task in male collegiate soccer athletes without perceived ankle instability

OBJECTIVES To investigate whether ankle joint laxity alone influences lower limb kinematics during a side-cutting task. DESIGN A cross-sectional study. SETTING Sports medicine research laboratory. PARTICIPANTS In total, 66 male collegiate soccer players with history of ankle sprains with no perceived ankle instability were categorised into three groups: no-laxity copers (n = 26), laxity copers (n = 23), and severe-laxity copers (n = 17). MAIN OUTCOME MEASURES The hip, knee, ankle, rearfoot, midfoot, and forefoot kinematic data during the stance phase (0%-100% indicated initial contact to take-off) of a 45° side-cutting task were analysed using one-dimensional statistical parametric mapping. RESULTS The horizontal plane kinematics of the rearfoot differed significantly among the three groups during 30%-91% of the stance phase (P < .05). Severe-laxity copers exhibited a greater external rotation angle than no-laxity copers during 6%-14% and 32%-92% of the stance phase (P < .05). CONCLUSION Our data suggest that severe ankle joint laxity affects rearfoot horizontal plane kinematics in individuals without perceived ankle instability performing a 45° side-cutting task. These findings could be used by clinicians in developing rehabilitation programs to prevent further ankle sprains in patients with severe ankle joint laxity.