Reproducibility and reliability of measurements using a linear isokinetic dynamometer, Aristokin

Area of Science:

• Biomechanics
• Human Movement Analysis
• Exercise Physiology

Background:

• Assessing intra-observer reproducibility and reliability of isokinetic dynamometer measurements is crucial for accurate biomechanical analysis.
• The Aristokin linear isokinetic dynamometer was utilized to evaluate measurement consistency.

Purpose of the Study:

• To determine the intra-observer reproducibility and reliability of measurements obtained from a linear isokinetic dynamometer.
• To identify which measurement repetitions yield the most consistent and reliable data.

Main Methods:

• Sixteen young female volunteers performed 4 test sessions involving standardized warming-up and 4 different isokinetic movements (elbow/shoulder flexion, total body lifting, leg extension).
• Measurements of force, power, and explosivity were recorded at specific velocities (65 cm/sec, 40/60 cm/sec) over a 6-week period.
• Data analysis focused on reproducibility within sessions and reliability between sessions.

Main Results:

• Highest reproducibility for mean peak power and force was observed using repetitions 3-6 (ICC 0.85-0.99).
• Reliability between sessions was high for mean force and power in most movements, with no significant learning effect noted.
• The first two repetitions showed lower reproducibility and reliability, particularly for explosivity and early force/power development.

Conclusions:

• The initial 2 repetitions of isokinetic measurements, even after warm-up, are not reproducible and should be excluded from analysis.
• Utilizing repetitions 3-6 provides high reliability for measuring mean force and power in total lifting and leg extension movements.
• This finding enhances the validity of isokinetic testing protocols for assessing human strength and power.