Gait Retraining Using Real-time Kinematic Biofeedback To Decrease Torsional Loads

Abstract

Overuse injuries among runners are believed to be related, in part, to abnormal mechanics. Successful management of these injuries requires the abnormal mechanics to be addressed. PURPOSE to examine the effect of gait retraining in a runner with foot pain thought to be related to abnormal mechanics. METHODS 16 y.o. female soccer/track athlete presenting with pain under bilateral 1st MTP joints (left pain worse than right) and left knee pain associated with running. Visual inspection of her running mechanics revealed significantly increased in-toeing during stance for bilateral lower extremities, left greater than right. When asked to run with toe-out, the foot pain decreased. We hypothesized that her increased in-toeing generates greater torsional loads between her foot and the ground which, over repeated exposures, contributes to her symptoms. Prior to gait retraining, five trials of 3D kinematics (Vicon motion analysis 120 Hz) and kinetics (Bertec force plate, 1080 Hz) were collected while running at 3.7 (±0.2) m/s. The patient next participated in 13 training sessions where she was provided real-time kinematic biofeedback on her toe-out angle during treadmill running. To facilitate motor learning, progressively less feedback was provided during the 30 minute training sessions. Running mechanics were again recorded for five trials at the conclusion of the retraining sessions. Mechanical variables of interest were the peak free moment (Mzf), net angular impulse of the free moment (NAI), foot abduction angle toe-out angle in the lab reference frame (TO). It was expected that ABD and TO would increase and Mzf and NAI would decrease after training. RESULTSTableCONCLUSION The results of this case study suggest that gait training using real-time biofeedback can increase ABD and TO angles and decrease torsional loads to the foot (Mfz). The 77% decrease in Mfz may be responsible for the improvement in pain during activity reported by the patient after training. The patient will continue to be observed to determine the persistency of these gait changes.