Assessing the reliability of baseline maximum voluntary contraction protocols.

Area of Science:

• Biomechanics
• Human Physiology
• Exercise Science

Background:

• Maximum Voluntary Isometric Contractions (MVICs) are crucial for normalizing exercise intensity.
• Existing MVIC protocols show significant variability and lack consensus on reliability.
• This variability impacts the consistency of research and clinical measurements.

Purpose of the Study:

• To identify the optimal baseline MVIC calculation method for maximizing between-session reliability.
• To address the lack of standardized protocols in MVIC measurement.
• To enhance the consistency of strength assessment in research and clinical settings.

Main Methods:

• Eighteen participants completed knee extension, elbow flexion, and hand grip MVICs across four sessions.
• Thirty-two distinct MVIC calculation methods were analyzed, varying contraction count, peak vs. average, and inclusion of familiarization/practice.
• Reliability was assessed using Intraclass Correlation Coefficients (ICCs) with significance set at p ≤ 0.05.

Main Results:

• Between-day ICCs ranged from 0.85 to 0.99, indicating generally high reliability across methods.
• Using the peak of a single contraction demonstrated high reliability and efficiency.
• Familiarization and practice sessions only improved reliability for elbow flexion MVICs.

Conclusions:

• Multiple methods for calculating baseline MVICs yield reliable results.
• The most efficient and practical method involves using the peak value from a single contraction.
• This optimized protocol balances high reliability with reduced testing time and participant burden.