Isometric Strength Database for Muscle Maximal Voluntary Endurance Field Tests: Normative Data

Area of Science:

• Exercise physiology
• Biomechanical analysis
• Human performance evaluation

Background:

• Current muscle endurance tests lack normative values considering individual anthropometric data.
• Factors like weight, height, gender, and age significantly impact muscle performance.
• Existing tests do not fully capture maximal voluntary isometric endurance across diverse populations.

Purpose of the Study:

• To assess the test-retest reproducibility of eight isometric muscle field tests.
• To establish muscle endurance norms for a healthy population, stratified by anthropometric characteristics.
• To enable a comprehensive and rapid evaluation of muscle function.

Main Methods:

• A case series design was employed in two phases.
• Phase 1: Assessed inter- and intra-assessor reproducibility of eight isometric tests in 20 adults (mean age 40.9 years).
• Phase 2: Established muscle maximal voluntary isometric endurance norms in 400 healthy adults (200 males, 200 females) across age groups (20-59 years).

Main Results:

• All eight muscle measurements demonstrated good intra- and inter-assessor reproducibility (ICC: 0.915–0.996; CV: 3.6–11.8%).
• Tests showed good sensibility (AUC > 0.7) and consistent muscle belt ratios across age and gender.
• Anthropometric characteristics were found to significantly influence isometric test performance.

Conclusions:

• Prediction equations were developed for a healthy population, incorporating anthropometric characteristics.
• Agonist/antagonist ratios were established for eight isometric muscle field tests.
• The study confirmed good reproducibility for all tested isometric muscle field tests.