Research

Longitudinal analyses of participants with a history of lateral ankle sprain are lacking. This investi- gation combined measuresof inter-joint coordination and stabilometryto evaluate eyes-open (condition 1)and eyes-closed (condition 2) static unilateral stance performance in a group of participants, 6-months after they sustained an acute, fi rst-time lateral ankle sprain in comparison to a control group. Methods: Sixty-nine participants with a 6-month history of fi rst-time lateral ankle sprain and 20 non-injured controls completed three 20-second unilateral stance task trials in conditions 1 and 2. An adjusted coef fi cient of multiple determination statistic was used to compare stance limb 3-dimensional kinematic data for similarity in the aim of establishing patterns of lower-limb inter-joint coordination. The fractal dimension of the stance limb centre of pressure path was also calculated. Findings: Between-groupanalysesrevealedsigni fi cantdifferencesinstancelimbinter-jointcoordinationstrategies for conditions 1 and 2, and inthe fractal dimension of the centre-of-pressure path for condition 2 only. Injured par- ticipantsdisplayedincreasesinankle – hiplinkedcoordinationcomparedtocontrolsincondition1(sagittal/frontal plane: 0.15 [0.14] vs 0.06 [0.04]; η 2 = .19; sagittal/transverse plane: 0.14 [0.11] vs 0.09 [0.05]; η 2 = 0.14) and condition 2 (sagittal/frontal plane: 0.15 [0.12] vs 0.08 [0.06]; η 2 =0.23),withanassociateddecreaseinthefractal dimension of the centre-of-pressure path (injured limb: 1.23 [0.13] vs 1.36 [0.13]; η 2 =0.20). Interpretation: Participants with a 6-month history of fi rst-time lateral ankle sprain exhibit a hip-dominant coordi- nation strategy for static unilateral stance compared to non-injured controls.