Reduced muscle function in patients with osteoarthritis

Area of Science:

• Orthopedics
• Rehabilitation Medicine
• Biomedical Engineering

Background:

• Knee osteoarthritis (OA) is a prevalent degenerative joint disease.
• Muscle dysfunction is a common comorbidity in knee OA, impacting patient mobility.
• The relationship between specific muscle function deficits and overall functional capacity in knee OA requires further elucidation.

Purpose of the Study:

• To compare muscle strength, endurance, and contraction velocity in individuals with knee OA versus healthy controls.
• To investigate the correlation between reduced muscle function and diminished functional capacity in knee OA patients.
• To assess if muscle function deficits vary at different muscle lengths.

Main Methods:

• A comparative study involving patients with knee OA and age-matched healthy controls.
• Assessment of functional capacity, activities of daily living (ADLs), and pain levels.
• In vivo measurement of maximal isometric strength (length-tension relationship), endurance (force-time relationship) for knee flexion/extension, and maximal angular velocity (force-velocity relationship) for knee extension.

Main Results:

• Knee OA patients reported increased difficulty and pain during ADLs.
• Significantly lower muscle strength was observed in knee OA patients for extension (72%) and flexion (56%).
• Reduced muscle endurance for quadriceps (203%) and hamstrings (214%), and lower contraction velocity (128%) were noted, with greater deficits at longer muscle lengths.

Conclusions:

• Patients with knee OA exhibit substantial reductions in muscle strength, endurance, and contraction velocity.
• These muscle function deficits are associated with impaired functional capacity in individuals with knee OA.
• The findings highlight the importance of addressing muscle dysfunction in the management of knee OA.