Knee OA Therapy Should Target Both Strength and Speed of Force

An observational study conducted by researchers at University of Kansas Medical Center has provided further insight into the association between lower limb muscle tone and risk for development or worsening of knee osteoarthritis (OA). Quadricep muscle weakness has previously been known as a risk factor for knee OA, and the present work sought to further investigate the role of speed force production (SPF)--defined as how fast the quadracep muscle can generate force-as a risk factor for impaired physical function in OA sufferers. Team leader Neil Segal, MD, MS, commented, “Better understanding of the relationship of speed of muscle force development and worsening physical function could inform design of rehabilitation interventions to protect people from suffering loss of physical function.”

The study engaged participants in the Osteoarthritis Initiative, comprised of almost 5,000 adults with knee OA or at risk for the condition. SPF was measured and categorized as low, medium, or high, and corresponding physical function was gauged both through timed activity tests and via participant self-reports using the WOMAC-PF scale. At 36 months, participants with medium or high SPF showed lower risk for decline in physical function than those with low SPF. The authors concluded that their findings suggest that interventions to sustain physical function in patients with knee OA should focus both on building quadriceps strength and SPF of the quadriceps muscle. The results were reported last week at the Association of Academic Physiatrists Annual Meeting in Las Vegas.

Read a news story about the findings here.