Reducing Walking Speed Decreases Surgical Knee Loading but Not Between-Limb Symmetry in Individuals With Anterior Cruciate Ligament Reconstruction.

A higher risk of knee osteoarthritis (OA) has been identified in patients with slower walking speeds following anterior cruciate ligament reconstruction (ACLR). Given that altered loading of the surgical knee has been the most proposed mechanism for early knee OA post-ACLR, understanding how modulating walking speed may modify knee joint loading is essential for developing strategies to reduce the risk of knee OA in ACLR patients. The purpose of this study was to determine how modulation of walking speed affects knee joint loading during overground walking post-ACLR. Lower extremity kinematics and kinetics were recorded during overground walking at a self-selected, slower, and faster speed from 16 patients with unilateral ACLR. The results showed that ACLR patients demonstrated lesser peak knee flexion and adduction moments of the surgical knees when walking at slower speeds. However, modulating walking speed did not alter between-limb knee loading asymmetry. The ACLR limbs had lower peak knee flexion moments than the uninjured limbs across all 3 walking speeds. Although interventions that increase walking speed may deter the onset of knee OA by elevating the mechanical stimulation at the surgical knee, additional gait training strategies may be needed to restore the between-limb loading symmetry in ACLR patients.