Validity, Reliability, and Sensitivity of a Commercially Available Velocity Measuring Device When Performing Selected...

Area of Science:

• Biomechanics
• Exercise Physiology
• Sports Technology

Background:

• Linear position transducers (LPTs) are crucial for quantifying movement velocity in resistance training.
• The Tendo unit is a validated LPT, but new devices require rigorous assessment.
• Accurate velocity measurement aids in optimizing training loads and monitoring athlete progress.

Purpose of the Study:

• To determine the validity, reliability, and sensitivity of the RepOne LPT.
• To compare the RepOne LPT against the validated Tendo LPT.
• To assess performance during barbell back squat and bench press exercises across various intensities.

Main Methods:

• Fourteen recreationally trained individuals performed back squats and bench presses at 30-90% of their 1-repetition maximum (1RM).
• The RepOne and Tendo LPTs concurrently recorded average concentric velocity (ACV) and peak concentric velocity (PCV) for each repetition.
• Statistical analyses included correlation coefficients, intraclass correlation coefficients (ICCs), and Bland-Altman plots.

Main Results:

• Strong correlations (r = 0.74-0.99) and good to excellent reliability (ICCs = 0.79-0.99) were found between RepOne and Tendo for both exercises.
• Bland-Altman analysis indicated minimal bias for ACV, with slightly greater bias for PCV.
• RepOne generally showed higher smallest detectable change (SDC) and smallest worthwhile change (SWC) values compared to Tendo.

Conclusions:

• The RepOne LPT demonstrates strong validity and reliability for assessing barbell back squat and bench press velocity.
• Its performance is comparable to the established Tendo unit.
• RepOne is a viable tool for resistance training applications, with considerations for its sensitivity metrics.