Test-retest reliability of the biodex isokinetic dynamometer

Area of Science:

• Biomechanics and Sports Medicine
• Musculoskeletal Rehabilitation

Background:

• Assessing knee extension/flexion strength and work is crucial in sports medicine and rehabilitation.
• The Biodex isokinetic dynamometer is a common tool for such assessments, but its test-retest reliability needs verification.

Purpose of the Study:

• To evaluate the test-retest reliability of the Biodex isokinetic dynamometer's concentric mode for knee extension and flexion.
• To determine reliability for peak torque and work parameters in healthy, active adults.

Main Methods:

• Nineteen healthy adults (ages 20-35) underwent bilateral knee extension/flexion testing on the Biodex system.
• Testing included concentric modes at speeds of 60, 180, 240, and 300 degrees/second.
• Subjects were retested after seven days using identical protocols, with peak torque and single repetition work analyzed.

Main Results:

• High intraclass correlation coefficients (ICCs) were found for knee extension peak torque across all tested speeds (r = 0.95-0.97).
• Knee extension work also demonstrated high ICCs (r = 0.95-0.97) across all speeds.
• All ICC values were statistically significant at the p < 0.05 level.

Conclusions:

• The Biodex isokinetic dynamometer's concentric mode exhibits excellent test-retest reliability for peak torque and work measurements in healthy, active individuals.
• This confirms the device's suitability for consistent strength and work assessments in clinical and research settings.