Locomotive biomechanics in persons with chronic ankle instability and lateral ankle sprain copers

ABSTRACT: To compare the locomotive biomechanics of participants with chronic ankle instability (CAI) to those of lateral ankle sprain (LAS) copers. Cross-sectional study. Twenty-eight participants with CAI and 42 LAS copers each performed 5 self-selected paced gait trials. 3-D lower extremity temporal kinematic and kinetic data were collected for these participants from 200ms pre- to 200ms post-heel strike (period 1) and from 200ms pre- to 200ms post-toe off (period 2). The CAI group displayed increased hip flexion bilaterally during period 1 compared to LAS copers. During period 2, CAI participants exhibited reduced hip extension bilaterally, increased knee flexion bilaterally and increased ankle inversion on the 'involved' limb. They also displayed a bilateral decrease in the flexor moment pattern at the knee. Considering that all of the features which distinguished CAI participants from LAS copers were also evident in our previously published research (within 2-weeks following acute first-time LAS); these findings establish a potential link between these features and long-term outcome following first-time LAS. Clinicians must be cognizant of the capacity for these movement and motor control impairments to cascade proximally from the injured joint up the kinetic chain and recognise the value that gait re-training may have in rehabilitation planning to prevent CAI.