Single-leg drop landing motor control strategies following acute ankle sprain injury

No research currently exists investigating the effect of acute injury on single-limb landing strategies. The aim of the current study was to analyse the coordination strategies of participants in the acute phase of lateral ankle sprain (LAS) injury. Thirty-seven participants with acute, first-time, LAS and nineteen uninjured participants completed a single-leg drop landing task (DL) on both limbs. 3-dimensional kinematic (angular displacement) and sagittal plane kinetic (moment of force) data were acquired for the joints of the lower extremity, from 200ms pre-initial contact (IC) to 200ms post IC. The peak magnitude of the vertical component of the ground reaction force (GRF) was also computed. Injured participants displayed a bilateral increase in hip flexion, with altered transverse plane kinematic profiles at the knee and ankle for both limbs (p < 0.05). This coincided with a reduction in the net supporting flexor moment of the lower extremity (p < 0.05) and magnitude of the peak vertical GRF for the injured limb (21.82 ± 2.44 N/kg vs 24.09 ± 2.77 N/kg; p = 0.013) in injured participants compared to control participants. These results demonstrate that compensatory movement strategies are utilized by participants with acute LAS to successfully reduce the impact forces of landing.