Maximal isometric muscle strength: normative values and gender-specific relation to age

Area of Science:

• Gerontology
• Musculoskeletal Health
• Biomedical Engineering

Background:

• Limited data exists on age-related changes in maximal isometric muscle strength (MIMS) across numerous functional muscle groups (FMGs).
• Assessing MIMS is crucial for understanding age-related declines and for clinical evaluations.

Purpose of the Study:

• To establish normative values for MIMS across 51 FMGs in healthy adults aged 20-82 years.
• To analyze gender and side-specific differences in MIMS.
• To compare the age-related decline of MIMS between men and women.

Main Methods:

• MIMS was measured using a hand-held pull gauge in 290 women and 253 men.
• Data was analyzed using linear quantile regression to create gender- and side-specific percentile curves.
• A biphasic model was developed to describe strength changes over age.

Main Results:

• Men exhibited significantly higher MIMS than women, and the right side was stronger than the left.
• A biphasic strength decline was observed, with transitions around age 55 for women and 49 for men.
• Muscle strength decreased significantly after the transition phase, with a steeper decline in women.

Conclusions:

• The study provides gender-specific equations for calculating normative MIMS values based on age.
• These normative values facilitate objective assessment of diminished muscle strength in various clinical conditions and aging populations.
• Significant differences in age-dependent MIMS decline were observed between genders.