Does knee malalignment mediate the effects of quadriceps strengthening on knee adduction moment, pain, and function in medial knee osteoarthritis? A randomized controlled trial

The objective of this study was to examine whether the effects of 12 weeks of quadriceps strengthening on the knee adduction moment, pain, and function in people with medial knee osteoarthritis (OA) differ in those with and without varus malalignment. 107 participants were randomized into either a 12-week supervised home-based quadriceps strengthening group or a control group with no intervention. Quadriceps strengthening did not significantly alter the knee adduction moment in either the more malaligned or the more neutral group. Function did not improve significantly following quadriceps strengthening in either alignment group, but there was a significant improvement in knee pain in the more neutrally aligned group.  Quadriceps strengthening did not have any significant effect on the knee adduction moment in participants with either more varus or more neutral alignment.

The benefits of quadriceps strengthening on pain were more evident in those with more neutral alignment. Knee alignment thus represents a local mechanical factor that can mediate symptomatic outcome from exercise interventions in knee OA.

Arthritis Care & Research, 2008, 59(7), 943 – 951

Link to Abstract