Comparison of measures using the first test of 15 leg extensions per leg between a gold standard dynamometer (Humac Norm) and two variations of a custom-built isokinetic dynamometer (1080 Quantum).

<p>Comparison of measures using the first test of 15 leg extensions per leg between a gold standard dynamometer (Humac Norm) and two variations of a custom-built isokinetic dynamometer (1080 Quantum).</p

Configuration of the 1080 Quantum attached to Model A leg extension.

<p>The power outputs (W) would be presented on the <b>A.</b> tablet, calculated from the <b>B.</b> 1080 Quantum. The participant would sit in the leg extension machine and kick the <b>C.</b> movement arm outwards to complete the leg extension. The <b>D.</b> range of motion apparatus was in place to suspend the extension, bringing the participant’s leg back to the neutral position to be prepared for subsequent extensions. Finally, the participant was secured with a <b>E.</b> harness.</p

Schematic timeline of experimental protocol.

<p>Warm-up of both legs was initiated before the exercise protocol of 15 maximal concentric leg extensions at an equivalent of 180° s^-1 on both legs at each visit. Repeated tests were performed on Model A and Model B, with a single test performed on the Humac Norm, separated by at least 48 hours.</p

Reliability of measures between two tests (pre and post) of 15 leg extensions per leg on two variations of a custom-built isokinetic dynamometer, the 1080 Quantum.

<p>Reliability of measures between two tests (pre and post) of 15 leg extensions per leg on two variations of a custom-built isokinetic dynamometer, the 1080 Quantum.</p

Testing a novel isokinetic dynamometer constructed using a 1080 Quantum

<div><p>This study sought to assess the reliability and comparability of two custom-built isokinetic dynamometers (Model A and Model B) with the gold-standard (Humac Norm). The two custom-built dynamometers consisted of commercially available leg extension machines attached to a robotically controlled resistance device (1080 Quantum), able to measure power, force and velocity outputs. Twenty subjects (14m/6f, 26±4.8yr, 176±7cm, 74.4±12.4kg) performed concentric leg extensions on the custom-built dynamometers and the Humac Norm. Fifteen maximal leg extensions were performed with each leg at 180° s^-1, or the linear equivalent (~0.5m s^-1). Peak power (W), mean power (W), and fatigue indexes (%) achieved on all three devices were compared. Both custom-built dynamometers revealed high reliability for peak and mean power on repeated tests (ICC>0.88). Coefficient of variation (CV) and standard error of measurement (SEM) were small when comparing power outputs obtained using Model A and the Humac Norm ( CV = 9.0%, SEM = 49W; peak CV = 8.4%, peak SEM = 49W). Whereas, Model B had greater variance ( CV = 13.3% SEM = 120W; peak CV = 14.7%, peak SEM = 146W). The custom-built dynamometers are capable of highly reliable measures, but absolute power outputs varied depending on the leg extension model. Consistent use of a single model offers reliable results for tracking muscular performance over time or testing an intervention.</p></div