Peña García-Orea, GuillermoBelando Pedreño, NoeliaMerino Barrero, Juan AndrésJiménez Ruiz, AbelHeredia Elvar, Juan Ramón2020-11-062020-11-062021Peña García-Orea, G., Belando-Pedreño, N., Merino-Barrero, J. A., Jiménez-Ruiz, A., & Heredia-Elvar, J. R. (2021). Validation of an opto-electronic instrument for the measurement of weighted countermovement jump execution velocity. Sports Biomechanics, 20(2), 150–164. https://doi.org/10.1080/14763141.2018.15263161476-31411752-6116http://hdl.handle.net/11268/9340The purpose of this study was to analyse the reliability and validity of an opto-electronic sensor system (Velowin) compared to a linear velocity transducer (T-Force System) considered as the gold standard. Mean velocity (MV) and peak velocity (PV) generated in the Smith machine bar placed on the shoulders in counter-movement jump exercise (CMJ) were analysed. The study was conducted with a sample of 21 men with experience in resistance training. Five measurements were analysed for CMJ exercise in concentric phase using a progressive loading increase. Three jumps were made per load with a 3-4 min recovery between loads. The analysis of the variance confirmed that there were no significant differences (p > 0.05) in the execution velocity between Velowin and T-Force with each of the loads. The reliability analysis showed, with each of the loads, high values of the intraclass correlation coefficient (ICC = 0.95-0.99) and a 'substantial' Lin´s concordance coefficient in MV (CCC ≥0.96) and between 'substantial' (CCC = 0.98) and 'almost perfect' (CCC = 0.99) in PV. These results confirm the reliability and validity of the Velowin device is reliable for measuring the execution velocity in loaded CMJ exercise.engjournal article10.1080/14763141.2018.1526316restricted accessDispositivos optoelectrónicosTransductoresEntrenamiento deportivoTecnología electrónicaDeporte