A NEW study from the Multicenter Osteoarthritis Study (MOST) has found that adults with weaker knee extensor muscles, particularly the quadriceps—are significantly more likely to experience worsening knee pain and develop frequent pain over time. The findings highlight the importance of muscle power as a potential target for osteoarthritis (OA) prevention and management.
Muscle Weakness May Worsen Pain
The research team, led by Dr. Chun-Hao Huang and colleagues including Neil A. Segal and David T. Felson, examined data from adults with or at risk for knee OA. Participants’ knee extensor power was measured at baseline using isotonic contractions, movements performed at a consistent resistance equivalent to 40% of their one-repetition maximum.
Pain levels were tracked over a two-year period using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and assessments for frequent knee pain (FKP), defined as pain on most days in the past month.
When participants were divided into quartiles based on their knee extensor power, those in the weakest group had up to 1.95 times greater odds of developing frequent knee pain compared to those in the strongest group. Even moderate declines in strength were associated with higher pain risk over time.
Implications for Osteoarthritis Management
The results suggest that muscle power, not just strength, plays a crucial role in maintaining knee joint health.
The researchers noted that interventions aimed at improving quadriceps power, such as progressive resistance training or neuromuscular exercises, could be particularly beneficial in slowing pain progression and improving function in individuals at risk for OA.
A Case for Prevention
Knee osteoarthritis remains one of the leading causes of disability among older adults worldwide, and effective non-pharmacological interventions are urgently needed. By focusing on muscle power training, clinicians may be able to help patients maintain mobility and delay the need for surgical interventions such as joint replacement.
Reference
Huang CH et al. Effect of Knee Extensor Power on Knee Pain in Adults With or at Risk for Osteoarthritis: The Multicenter Osteoarthritis Study. J Rheumatol. 2025;DOI: 10.3899/jrheum.2025-0621.
