Knee extension rate of torque development and peak torque: associations with lower extremity function

Area of Science:

• Gerontology
• Kinesiology
• Muscle Physiology

Background:

• Muscle force generation declines with aging, impacting physical functions like walking.
• Peak torque measures are common, but rate of torque development (RTD) offers a dynamic assessment of muscle performance crucial for function.

Purpose of the Study:

• To determine if RTD significantly predicts lower extremity performance beyond peak torque in older adults.
• To explore RTD's potential role in identifying individuals susceptible to functional decline.

Main Methods:

• 1089 participants from the Baltimore Longitudinal Study of Aging (BLSA) were analyzed.
• Peak torque and RTD of knee extension were measured; lower extremity performance was assessed via gait speed, walking endurance, and chair stand tests.
• Sex-stratified regression models adjusted for demographics, BMI, and body composition.

Main Results:

• In men, RTD independently predicted most lower extremity performance tests.
• In women, RTD was only a significant independent correlate of fast-paced 6-meter walking speed.
• RTD's independent contribution to physical function varied by sex.

Conclusions:

• RTD independently contributes to physical function in older men, suggesting its utility in assessing dynamic muscle strength.
• The association between RTD and physical function is less pronounced in women, indicating potential sex-based differences requiring further investigation.
• RTD may serve as a valuable tool for screening and intervention strategies targeting physical function decline in older adults.