Efficacy of a Cycling Intervention with Pedal Reaction Force Augmented Feedback on Reducing Inter-Limb Asymmetries in Patients with Unilateral Total Knee Arthroplasty

Fifteen patients with unilateral total knee arthroplasty (TKA) performed cycling at two workates (80 W and 100 W) and two walking conditions (preferred and fast speeds). Ten of these patients of TKA also participated in a short-term cycling intervention paired with visual augmented feedback of vertical pedal reaction forces for six sessions over two-three weeks. These ten patients of TKA participated in a 2^nd post-training testing session. Study One compared the knee joint biomechanics for all fifteen participants during stationary cycling to ascertain if any biomechanical asymmetries may be present. The replaced limbs displayed significantly lower peak knee extension moment (KEM) and vertical pedal reaction (PRF) compared to non-replaced limbs during stationary cycling. Study Two examined the effect of the short-term cycling intervention on the knee joint biomechanics and biomechanical asymmetries during stationary cycling for the selected ten patients of TKA. The short-term cycling intervention had no significant effect for peak KEM or vertical PRF asymmetries during stationary cycling. Peak KEM asymmetries did decrease by 10% and 9.9% at 80 W and 100 W, respectively. Study Three examined the effect of the short-term cycling intervention on the knee joint biomechanics and biomechanical asymmetries during gait. Similarly, the short-term cycling intervention had no effect on peak KEM asymmetries and vertical ground reaction force (GRF) asymmetries during both walking condition. Study Four compared the estimated tibiofemoral joint forces during stationary cycling between the replaced and non-replaced limbs of the fifteen patients of TKA. The replaced limbs also had lower medical tibiofemoral contact force (MCF) compared to the non-replaced limbs during stationary cycling at 80 W. The non-replaced limb had greater peak MCF compared to the lateral tibiofemoral contact force (LCF). Unilateral TKA patients cycling with similar reductions of KEM in their replaced limbs. During cycling, there was no difference between MCF and LCF for the replaced limbs, potentially indicating a successful operation to restore knee joint alignment. In summary, the use of a short-term cycling intervention with augmented feedback for six sessions were not significantly beneficial for addressing KEM asymmetries in both cycling and gait. However, the 10% reductions of peak KEM asymmetries may indicate some clinical benefits of this intervention. Future studies should examine similar interventions with an increased number of training sessions.