Knee biomechanics of patients with total knee replacement during downhill walking on different slopes

Purpose: The purpose of this study was to compare knee biomechanics of the replaced limb to the non-replaced limb of total knee replacement (TKR) patients and healthy controls during walking on level ground and on decline surfaces of 5 degrees, 10 degrees, and 15 degrees. Methods: Twenty-five TKR patients and 10 healthy controls performed 5 walking trials on different decline slopes on a force platform and an instrumented ramp system. Two analyses of variance, 2 x 2 (limb x group) and 2 x 4 (limb x decline slope), were used to examine selected bio-mechanics variables. Results: The replaced limb of TKR patients had lower peak loading-response and push-off knee extension moment than the non-replaced and the matched limb of healthy controls. No differences were found in loading-response and push-off knee internal abduction moments among replaced, non-replaced, and matched limb of healthy controls. The knee flexion range of motion, peak loading-response vertical ground reaction force, and peak knee extension moment increased across all slope comparisons between 0 degrees and 15 degrees in both the replaced and non-replaced limb of TKR patients. Conclusion: Downhill walking may not be appropriate to include in early stage rehabilitation exercise protocols for TKR patients.

Automated summary

This study compared the knee biomechanics of TKR patients and healthy controls during walking on different slopes. The results showed that the replaced limb of TKR patients had lower peak loading-response and push-off knee extension moment. In downhill walking, the knee flexion range of motion, peak loading-response vertical ground reaction force, and peak knee extension moment increased for TKR patients.