Reliability and validity assessment of a linear position transducer

Area of Science:

• Sports Science
• Biomechanics
• Exercise Physiology

Background:

• Accurate measurement of movement velocity and power is crucial for effective resistance training.
• Linear position transducers are commonly used devices for assessing these variables.
• The Tendo Weightlifting Analyzer System is one such device requiring validation.

Purpose of the Study:

• To determine the validity and reliability of the Tendo Weightlifting Analyzer System for measuring peak velocity (PV), average velocity (AV), peak power (PP), and average power (AP).
• To assess measurement accuracy during bench press (BP) and full back squat (BS) exercises.

Main Methods:

• Validity was assessed by comparing Tendo System measurements with a criterion system (T-Force) during BP and BS in 71 trained males.
• Reliability was evaluated through test-retest measurements using the Tendo System in 32 males over two sessions a week apart.
• Intraclass correlation coefficients (ICCs), biases, and random errors were calculated.

Main Results:

• High validity ICCs (0.853–0.989) were found for the Tendo System.
• Strong test-retest reliability ICCs (0.922–0.988) were observed.
• Systematic biases and random errors were generally low, particularly for AV and AP, though higher for PP. Proportional biases were noted for most variables, except PV in BS.

Conclusions:

• The Tendo Weightlifting Analyzer System is a valid and reliable tool for measuring movement velocity and estimating power in resistance exercises.
• Low biases and errors, especially for AV and AP, support its use in monitoring resistance training programs.