Effective Dose Of A Real-time Gait Biofeedback Regimen Needed To Modify Vertical Ground Reaction Force In Individuals With Acl Reconstruction

Lesser peak vertical ground reaction force (p-vGRF) in the first half of the stance phase of gait indicates aberrant limb-level loading linked to osteoarthritis development in individuals with anterior cruciate ligament reconstruction (ACLR). Increasing p-vGRF to magnitudes equal to uninjured controls with real-time gait biofeedback (RTGBF) has been proposed as a rehabilitation tool for normalizing gait following ACLR. It remains unknown how many sessions of RTGBF are needed to elicit motor learning to preserve augmented p-vGRF. PURPOSE: Determine the effective dose (i.e., number of RTGBF sessions) required to elicit retention of a normalized p-vGRF in individuals with an ACLR. METHODS: Eleven individuals (10 Females, 22±4 years old, 30±19 months post-ACLR) participated in a 6-week, 18-session visual RTGBF regimen that cued individuals to achieve a p-vGRF target of 1.12 body weights (BW) using force data collected bilaterally on a step-by-step basis from a force-measuring treadmill. The RTGBF regimen utilized multiple evidence-based components to elicit motor learning (e.g., tapering, distributed practice, standard cues). The 1.12 BW p-vGRF target was chosen as it is equal to the p-vGRF of uninjured controls and asymptomatic ACLR patients. Prior to the beginning of each training session, p-vGRF was collected while participants walked on the treadmill without RTGBF. Using Kaplan-Meier curves, we determined the number of RTGBF sessions needed to retain the novel loading pattern that achieved the p-vGRF target (1.12 ± 0.015 BW) for both a single session and 2 consecutive sessions. The median effective dose was reported as the number of training sessions required for the probability of retaining the targeted p-vGRF to exceed 50%. RESULTS: The median effective dose to be able to retain the 1.12 BW p-vGRF target was 8 (95% CI: 0.6, 15.4) and 12 (95% CI: 6.1, 17.9) sessions for the single and 2 consecutive trial thresholds, respectively. CONCLUSION: The 12 sessions needed to achieve normalized loading with RTGBF using the more conservative 2 consecutive sessions effective dose measurement is well within the recommended number of rehabilitation sessions typically prescribed post-ACLR. RTGBF may be a feasible clinical approach for reducing osteoarthritis risk following ACLR. Arthritis Foundation