ACUTE ANKLE SPRAIN INJURY ALTERS KINEMATIC AND CENTRE OF PRESSURE MEASURES OF POSTURAL CONTROL DURING THE STAR EXCURSION BALANCE TEST

Background Postural control assessments are frequently used in clinical and research settings to evaluate movement deficits following acute lateral ankle sprain (LAS). The Star Excursion Balance Test (SEBT) is one such postural control assessment tool. To date, no research has investigated the immediate post-injury movement strategies associated with LAS, as quantified by center of pressure (COP) and kinematic analyses during performance of selected reach directions of the SEBT. Objective To compare the kinematic and COP patterns of a group with acute LAS and a non-injured control group during performance of selected reach directions of the SEBT. Design Cross-sectional. Setting University biomechanics laboratory. Participants 81 participants with acute LAS and 19 non-injured controls. Main outcome measures 3D kinematics of the hip, knee and ankle joints as well as associated fractal dimension (FD) of the COP path during the performance of the anterior (ANT), posterior-lateral (PL) and posterior-medial (PM) reach directions of the SEBT. Results The LAS group had bilateral decreased reach distances normalised to leg length in the ANT, PL and PM reach directions of the SEBT compared to non-injured control participants (P Conclusion Acute LAS is associated with bilateral deficits in postural control, evidenced by reduced angular displacements of the hip, knee and ankle joints, as well as reduced reach distances and FD of the COP path during the performance of a dynamic postural control assessment task.