Transversus abdominis activation does not alter gait impairments in patients with and without knee osteoarthritis

Background Knee osteoarthritis accounts for more years of disability than all other forms of osteoarthritis combined. Gait kinetic and kinematic changes, in addition to reduced gait speed, are commonly observed. This study investigates whether core activation, which modifies lower extremity movement in young, active populations, can alter the gait and baseline core activation of those with knee osteoarthritis as compared to controls, and alter osteoarthritic knee pain. Methods Forty-four participants (22 controls and 22 with knee osteoarthritis) underwent biomechanical gait assessment, examining kinetic and kinematic variables, in addition to gait speed, with and without volitional transversus abdominis activation. Surface electromyography was used to measure baseline transversus abdominis activation under both conditions. Knee pain ratings were examined for those with knee osteoarthritis. Findings No significant biomechanical differences were observed within groups, or in the time/group interaction. Between-groups kinetic (time to first peak ground reaction force and amplitude of second peak ground reaction force) and gait speed differences were observed under both conditions. There were no differences in baseline electromyography activation between or within-groups, or within-group for self-reported pain for the osteoarthritic group. Interpretation Although previous studies have shown the benefit of core activation in correcting lower extremity movement patterns and kinetic loading in young, athletic populations, this study is the first to show this is not the case for persons with knee osteoarthritis. Future studies should examine the value of a progressive core stabilization program, of sufficient dose and mode, in correcting the observed gait differences in those with knee osteoarthritis. Clinical Trial Registration Number: NCT03776981