Vibrações de corpo inteiro na interface cavalo-cavaleiro em situações dinâmicas

Abstract

Vibration is a mechanical stimulus characterized by periodic, regular or irregular oscillatory movements. In the human body, the vibrations are produced by the body contact mechanisms that move from its rest position. In this context, some authors have suggested that individuals riding position are exposed to the vibrations transmitted by the gait of the horse through contact between the saddle and the individual. The aim of this study was to analyze the magnitude of whole body vibration (WBV) in the horse-rider interface in dynamic situations. The study group was composed of eight female subjects, with a mean age of 25.5 ± 6.12 years, healthy and normal weight (body mass index 23.71 ± 1.52), with no experience in equestrian activities. The measurement of the transmitted WBV horse rider interface is accomplished by an inertial sensor, model 4447, from Brüel & Kjaer®. This equipment allows measurements of WBV situated in the range 1-80 Hz and is composed of a triaxial accelerometer set in a semi-rigid circular support that was fixed on two riding accessories used in research, and saddle blanket. The experiment was conducted in two areas previously determined surfaces of sand and asphalt without obstacles. In each area was demarcated a stretch of 10 meters where the horse was conducted while. The experiment was arranged in situations organized according to the mount accessory used, positioning the legs in the stirrups and the running surface of the horses. The results indicate that the horse running surface produces changes in the magnitude of the accelerations transmitted in horse rider interface; the magnitude of the accelerations in the horse rider interface shown to be higher in situations where the horse has moved to the asphalt surface using saddle as an accessory. Higher accelerations were perceived in the anteroposterior direction, vertical and lateral, respectively, regardless of attachment or horse running surface. The positioning of the foot in the stirrup influenced differently the magnitude of the accelerations transmitted in horse-rider interface.