Lower extremity coordination and symmetry patterns during a drop vertical jump task following acute ankle sprain.

PURPOSE Evaluate the potentially adaptive movement patterns associated with acute lateral ankle sprain (LAS) using biomechanical analyzes. METHODS Thirty participants with acute LAS and nineteen controls performed a drop vertical jump (DVJ) task. 3D kinematic and sagittal plane kinetic profiles were plotted for the hip, knee and ankle joints of both limbs for the drop jump (phase 1) and drop landing (phase 2) phases of the DVJ. Inter-limb symmetry and the rate of force development (RFD) relative to bodyweight (BW) during both phases of the DVJ were also determined. RESULTS The LAS group displayed reduced ankle plantar-flexion on their injured limb during phase 2 of the DVJ, with greater associated inter-limb asymmetry for this movement (p<.05). The LAS group also displayed altered kinetic profiles, with increased inter-limb hip asymmetry for both phases of the DVJ (p<.05). This was associated with a decrease in the LAS participants' injured limb RFD during phase 2 of the DVJ when compared with that of controls (11.76±3.43BW/s vs 14.60±3.20BW/s; p=.01, η(2)=0.14). CONCLUSION Participants with LAS display potentially aberrant coordination strategies during a DVJ as evidenced by an increased dependence on the non-injured limb.