Validity and Reliability of a Commercially-Available Velocity and Power Testing Device

Abstract

Given the relationship between explosive-type training and power adaptation, tracking movement velocity has become popular. However, unlike previous variables, tracking velocity necessitates the use of a valid and reliable tool to monitor adaptation over time. Therefore, the primary purpose of this research was to assess the validity and reliability of a commercially-available linear position transducer (LPT). Nine resistance-trained men completed four sessions consisting of a single set of barbell back squat to volitional failure at 75% or 90% one-repetition maximum. Kinetic and kinematic data were captured for each repetition by the LPT and a 3-dimensional motion capture system and bipedal force platforms. In total, 357 instances of data from both systems were analyzed using intraclass correlations (ICC), effect size estimates, and standard error of measurement. Overall, the LPT yielded excellent ICCs (all ≥0.94) and small/trivial differences (d < 0.60). When categorized by median values, ICCs remained high (all ≥0.89) and differences remained small or trivial with the exception of high peak velocities (d = −1.46). Together, these data indicate that the commercially-available LPT is a valid and reliable measure for kinetic and kinematic variables of interest with the exception of high peak velocities.

The Validity and Reliability of Commercially Available Resistance Training Monitoring Devices: A Systematic Review

“…Generally, linear transducers have shown the greatest accuracy with mean concentric velocity the most assessed outcome. However, to date, only the GymAware [9,25,26,54], T-Force [54], Open Barbell System [53], Tendo Fitrodyne [53,54,58], and Fitrodyne (Fitronic) [9] have been directly compared to a 'true' gold-standard 3D high-speed motion-capture system set-up during freeweight resistance training. When these devices have been directly compared to each other during free-weight exercises [9,53,54], it appears that the GymAware provides the greatest accuracy.…”

“…Of the 19 studies that have assessed the validity of linear transducers, 10 utilised a gold-standard criterion of highspeed 3D motion capture when assessing velocity [10, 24-27, 51, 53, 54] or force plate when assessing force [8,25,26,50] (Table 4). From the evidence provided, these types of devices tend to demonstrate greater accuracy when compared to accelerometers [8,9,26].…”

“…This is particularly important for practitioners who utilise this information to make decisions regarding subsequent training sessions. The validity of an instrument often refers to its ability to measure what it is intended to measure with accuracy and precision [25][26][27]. This is typically quantified by comparing the output of the respective instrument to a 'gold-standard' or criterion measure.…”

“…To ensure a true representation of each athlete's capacity, the reproducibility of each device needs to be considered. Typical measures of reliability include typical/standard error of measurement (TEM/SEM), CV, and intra-class correlations (ICC) [25,36,38].…”

Effect of acute antagonist static stretching on upper-body agonist power

“…29 The Gymaware PowerTool is considered both valid and reliable. 30,31 Participants performed three repetitions for each trial, and from the data collected, an average Pmax for each trial was calculated.…”