El análisis de la velocidad de carrera mediante sensores láser permite la obtención de datos en tiempo real siendo ventajosos frente a otros sistemas. El objetivo de este estudio fue valorar la validez y fiabilidad del sensor láser del sistema BioLaserSportÒ para el cálculo de velocidades medias y máximas mediante estadísticos relativos y absolutos. Los participantes fueron 17 varones (20.85 ± 1.54 años). Se utilizó un sensor láser tipo 1 (LDM301, Jenoptik, Germany) que registró posiciones de los deportistas a 2000 Hz. Los datos se trataron con la rutina DSL-30 creada con DasyLab v.10.0. Para la validación se utilizó un sistema de fotogrametría-2D con una cámara de alta velocidad (Exilim High Speed EX-F1, Casio) y SkillSpector v.1.3.2. (Video4coach, Grubbemollevej). Además, se utilizaron foto-células de doble haz (Polifemo Light, Microgate, Italy) y un cronómetro Racetime2 (Microgate, Italy). Se registraron, durante dos días, tres series de 30 m de carrera a máxima velocidad. El sensor láser proporcionó, con relación a la fotogrametría, diferencias en las velocidades medias y máximas de -0.11 m·s^-1 y 0.14 m·s^-1, respectivamente, con unos coeficientes de correlación superiores a 0.86, y mayores de 0.92 con las foto-células para las velocidades medias. Este mostró una excelente fiabilidad test-retest para las velocidades medias con un coeficiente de correlación intraclase (ICC) entre 0.7-0.9 y un error estándar de la media (SEM y SEM%), intrasesión e intersesión, menor de 0.05 m·s^-1 y 0.12 m·s^-1, respectivamente, y menores de 0.75% y de 2%, respectivamente. Para las velocidades máximas, los valores fueron menores de 0.10 m·s^-1 y 0.17 m·s^-1, respectivamente, y en ambos casos menores a 1.36% y 1,89%. El láser fue capaz de identificar mínimos cambios detectables (MDC y MDC%) intrasesión, para ambas variables, menores a 0.14 m·s^-1 y 0.29 m·s^-1, respectivamente (< 2.09% y < 3.76%) e intersesión, menores de 0.34 m·s^-1 y 0.47 m·s^-1 (< 5.56% y < 5.25%), respectivamente. En consecuencia, es un instrumento útil para el análisis de la evolución de la velocidad intrasujeto y entre sujetos en la carrera de velocidad entre 0-30 m, proporcionando resultados en tiempo real, pero se han de considerar los SEM, SEM%, MDC y MDC% para valorar la mejora del rendimiento.

Abstract

Speed running analysis using laser sensors allows to obtain data in real-time showing an advantage compared with other systems. The objective of this study was to assess the validity and reliability of the laser sensor of the BioLaserSport® system for the calculation of mean and maximum velocities using relative and absolute statistics tools. The participants were 17 men (20.85 ± 1.54 years). A laser sensor type 1 (LDM301, Jenoptik, Germany) was used to record positions of the subjects to 2000 Hz. The data were analyzed using DSL-30 routine created with DasyLab v.10.0. A Photogrammetry-2D system with a high-speed camera (Exilim High Speed EX-F1, Casio) and SkillSpector v.1.3.2. (Video4coach, Grubbemollevej) and a reference system 4 x 2 m² was used. Furthermore, a double photocell (Polifemo Light, Microgate, Italy) with an electronic stopwatch (Microgate, Italy) Racetime2 was used. Three series of 30 m sprint were recorded during two days. The results indicated that the laser sensor provided differences in mean and maximum velocities of -0.11 m·s^-1 and 0.14 m·s^-1, respectively. The correlation coefficients were higher than 0.86 in relation to photogrammetry and higher than 0.92 in relation to photo-cells. The laser system showed an excellent test-retest reliability for mean velocities with a coefficient of correlation intraclass (ICC) between 0.7-0.9. The standard error of the mean (SEM and SEM%), intra-session e inter-session, were lower than, 0.05 m·s^-1 and 0.12 m·s^-1, respectively, and in both cases less than 0.75% and 2%, respectively . In relation to maximum velocities, the values were lower than 0.10 m·s^-1 and 0.17 m·s^-1, respectively, and in both cases less than 1.36% and 1,89%. The minimum detectable change (MDC and MDC%) intra-session, for both variables, was lower than 0.14 m·s^-1 and 0.29 m·s^-1, respectively, (< 2.09% y < 3.76%). In relation to inter-session, the values were lower than 0.34 m·s^-1 and 0.47 m·s^-1 (< 5.56% y < 5.25%), respectively. Therefore, the laser system was a useful tool to analyze the evolution of the intra-subject and inter-subject velocity in a 30 m sprint running. Moreover, it provides results in real time, although assessing performance improvements must be considered the SEM, SEM%, MDC and MDC% values.

 http://dx.doi.org/10.5232/ricyde2012.03005

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