The effect of knee joint effusion on gait mechanics and muscle activation characteristics in moderate knee osteoarthritis

Abstract

Knee osteoarthritis (OA) is one of the most prevalent joint diseases, and knee effusion, as a manifestation of synovitis, is associated with knee OA clinical outcomes and disease progression. Thesis objectives were i) to determine whether an association between maximum suprapatellar recess (SPR) depth, and knee gait mechanics, muscle torques and activation amplitudes exists, and ii) to compare gait mechanics and knee joint muscle activations between individuals with and without effusion based on a cut-off value of 4 mm depth of the SPR. 50 participants were recruited, and knee joint motion was calculated from skin markers and moments calculated through inverse dynamics. Electromyography (EMG) of knee muscles was recorded using standardized procedures. No correlations were found between biomechanics and EMG data and SPR depth, however based on the 4 mm cut-off value, significant EMG alterations were found, which could be attributed to the sensitivity of the cut-off value.