Sedentary behavior and physical function: objective evidence from the Osteoarthritis Initiative.

Area of Science:

• Gerontology
• Orthopedics
• Rehabilitation Medicine

Background:

• Knee osteoarthritis (OA) significantly impacts physical function and quality of life.
• Sedentary behavior is prevalent in adults with knee OA, but its independent effect on physical function is not fully understood.
• Moderate-vigorous physical activity (MVPA) is known to benefit OA, but the role of reducing sedentary time requires further investigation.

Purpose of the Study:

• To investigate the relationship between sedentary behavior and physical function in adults with knee OA.
• To determine if this relationship persists after controlling for moderate-vigorous physical activity (MVPA) levels.
• To provide evidence-based recommendations for managing physical function in knee OA patients.

Main Methods:

• Objective measurement of sedentary behavior using accelerometers in 1,168 participants with knee OA.
• Assessment of physical function through 20-meter walk and chair stand tests.
• Cross-sectional analysis using multiple linear regression, adjusting for demographic, health, and MVPA factors.

Main Results:

• Adults with knee OA spent approximately two-thirds of their day in sedentary behavior.
• The most sedentary quartile exhibited significantly slower gait speed and lower chair stand rates compared to less sedentary groups.
• These associations remained statistically significant after adjusting for covariates, including MVPA.

Conclusions:

• Reduced sedentary behavior is independently associated with better physical function in knee OA patients.
• Findings support recommendations for knee OA patients to decrease sedentary time to enhance physical function.
• This study underscores the importance of addressing both physical activity and sedentary behavior for optimal OA management.