RESUMO
The aim of the study was to design an accurate and useful observational instrument for evaluating basic turn techniques in alpine skiing, and to determine its validity and reliability. A multi-step approach was used to design and validate the instrument: a literature revision; an expert meeting; a pilot test; the assessment of intra- and inter-observer reliability; a convergent validity test; and the responsiveness calculation with a pre- post-test. Results showed adequate values of intra-rater (P=0.80-0.83) and inter-rater reliability (P=0.86-0.97). For the convergent validity, a moderate statistically significant correlation for the speed and trajectory control dimensions were achieved (rho=0.58-0.65, p<0.001), but not for the balance position dimension (rho=0.24, p=0.166). The responsiveness was also acceptable (p<0.05, r=0.46-0.60). In conclusion, the Alpine Ski Technique Observation Instrument is a useful, reliable, valid, and responsive observational tool. (AU)
El objetivo del estudio fue diseñar un instrumento de observación preciso y útil para evaluar la técnica de cambios de dirección básicos en el esquí alpino, y determinar su validez y fiabilidad. Para diseñar y validar el instrumento se siguieron los siguientes pasos: revisión de la literatura, valoración por comité de expertos, prueba piloto, evaluación de la fiabilidad intra e inter-evaluador, prueba de validez convergente, y cálculo de sensibilidad con una prueba pre y post-intervención. Los resultados mostraron valores adecuados de fiabilidad intra-evaluador (P=0,80-0,83) e inter-evaluador (P=0,86-0,97). Respecto a la validez convergente se obtuvo una correlación moderada para las dimensiones de control de la velocidad y de la trayectoria (rho=0,58-0,65, p<0,001), pero no para la dimensión de posición de equilibrio (rho=0,24, p=0,166). La sensibilidad fue aceptable (p<0,05, r=0,46-0,60). En conclusión, el Instrumento de Observación de la Técnica en Esquí Alpino es una herramienta útil, fiable, válida y sensible. (AU)
Assuntos
Humanos , Masculino , Feminino , Adulto Jovem , Adulto , Esqui , Destreza Motora , Espanha , Reprodutibilidade dos TestesRESUMO
Whole-body vibration (WBV) is being promoted as an efficient complement to resistance training. The aim of this study was to investigate the effects of an 8-week program of WBV in combination with resistance training on knee extensors muscular performance. A group of 29 young adults (25 men, 4 women; age 21.8 ± 1.5) performed a WBV plus resistance training program (WBV + RES) or an identical exercise program in absence of vibration (placebo plus resistance training, PL + RES). Participants were evaluated for anthropometry, muscle strength (half-squat three repetition maximum, 3RM), knee extensors isokinetic dynamometry (180° and 60° s(-1)) and counter-movement jump (CMJ). After the intervention, percent body fat significantly decreased 2.1% only in WBV + RES (P < 0.001), while muscle mass significantly increased in both groups (P < 0.01): 2.2 and 2.8 kg in PL + RES and WBV + RES, respectively. No significant differences were observed in isokinetic strength or CMJ, and 3RM significantly increased in both groups (P < 0.001): 64.2 kg (52% of baseline) in PL + RES, and 46.9 kg (43%) in WBV + RES. The addition of WBV to resistance training during 8 weeks, in recreationally active young adults, did not result in a larger muscular performance improvement compared to an identical exercise program in absence of vibration. Muscle mass also seemed to be equally affected with or without vibration, yet body fat could be exclusively decreased by WBV. Further research is required to clarify whether WBV, as a complement to resistance training, produces additional specific benefits.
