Comparison of 2 forms of kinetic biofeedback on the immediate correction of knee extensor moment asymmetry following total knee arthroplasty during decline walking

U BACKGROUND: Individuals with total knee arthroplasty (TKA) display interlimb knee extensor moment (KEM) asymmetry during level walking that is exacerbated as task demands are increased. Studies using biofeedback to correct interlimb KEM asymmetry following TKA have reported mixed results. U OBJECTIVE: To compare the immediate effect of 2 forms of real-time kinetic biofeedback—vertical ground reaction force (vGRF) or KEM—on improving interlimb peak KEM symmetry during the weight-acceptance phase of decline walking in persons who have undergone TKA. U METHODS: In this cross-sectional, controlled laboratory study, 30 participants (17 men; mean ± SD age, 61.9 ± 8.5 years; body mass index, 28.4 ± 3.7 kg/m²) were allocated to either a vGRF or KEM real-time biofeedback group. Peak KEM interlimb asymmetry was obtained during both nonbiofeedback and biofeedback decline walking trials 3 months following TKA. U RESULTS: Significant interlimb asymmetry in peak KEM was observed in both groups during the nonbiofeedback condition (KEM, P = .02; vGRF, P<.01). The KEM biofeedback group demonstrated an immediate improvement in peak KEM asymmetry (P = .42). No change in peak KEM asymmetry was observed in the vGRF biofeedback group (P = .01). U CONCLUSION: Knee extensor moment biofeedback has an immediate effect on improving peak KEM asymmetry 3 months post TKA.