RESUMO
INTRODUCTION: Tolerance to breathing in conditions with a decreased oxygen ratio is subject-specific. A normobaric hypoxia tolerance test (NHTT) is performed to assess the ability of each individual, as this may be influenced by genetic or personal factors such as age or gender. The aim of this study is to test the influence of deep breathing on hypoxia tolerance time. MATERIAL AND METHODS: A total of 45 subjects (21 parachutists and 24 students) performed two NHTTs at 5050 m altitude (iAltitude). Arterial (SatO2) and muscle (SmO2) oxygen saturation were monitored with the Humon Hex® device. The first NHTT was performed with free breathing, without any instructions; and the second NHTT was performed with wide, slow, diaphragmatic breathing. The NHTT was terminated at the end of 10 min or when a value of less than 83% was obtained. RESULTS: The first NHTT was completed by 38.1% of parachutist and 33.3% of students while the second NHTT was completed by 85.7% and 75%, respectively. In the second NHTT, both parachutists and students had a significantly (p = 0.001) longer duration compared to the first NHTT. SmO2 and SatO2 values also increased significantly (p < 0.001) in both groups (p < 0.05). CONCLUSION: Performing controlled diaphragmatic breathing is successful in increasing hypoxia tolerance time and/or SatO2 values.
Assuntos
Hipóxia , Oxigênio , Humanos , Adulto , Altitude , Respiração , Fatores de TempoRESUMO
El Túnel de viento (WT) es un dispositivo que simula, gracias a una corriente vertical de aire, de 300 km/hora, la caída libre previa a la apertura del paracaídas. Se utiliza principalmente para el aprendizaje del paracaidismo militar de apertura manual. En su interior, un instructor ayuda y asesora al alumno en sus movimientos y posiciones. Nuestro objetivo es establecer la frecuencia de episodios de dolor lumbar en estos instructores e identificar factores relacionados. Material y método: Estudio retrospectivo en el que participaron 19 de los 23 Instructores de vuelo en activo de España. Hemos registrado el número de episodios de lumbalgia, antecedentes profesionales, actividad paracaidista y de actividad física. Además, grabamos las sesiones de trabajo de los instructores identificando las posturas, gestos y acciones compatibles con la producción de lumbalgias mecánicas. Resultados: El 78,9% de los Instructores han padecido dolor lumbar en el último año. No hemos encontrado diferencias significativas en la presencia de lumbalgias entre los grupos establecidos a partir del IMC, el número de saltos durante toda su trayectoria, las horas/semana en el WT y los años como instructor. Tampoco hay relaciones con la práctica de otras actividades físicas. Mediante la grabación en video se ha observado que, en el interior del WT, los instructores adoptan todas las posturas, gestos y movimientos relacionados con la producción del dolor lumbar inespecífico. Todas esas actividades actúan provocando sobrecargas musculares y articulares. Son hiperlordosis, actitudes cifóticas dorsales y lumbares, traslado de cargas, mantenimiento de contracciones isométricas y movimientos de torsión. Conclusiones: Existe una alta incidencia de dolor lumbar en los instructores del WT. Las actividades realizadas por estos profesionales son de riesgo para la producción de lumbalgias mecánicas; por lo que es necesario diseñar programas de prevención de este problema (AU)
Wind tunnel (WT) is a device that simulates, thanks to a vertical stream of air, 300 km/h, the free fall prior to the opening of the parachute. It is mainly used for learning the military manual opening parachuting. Inside, an instructor helps and assists the student in their movements and positions. Our objective is to establish the frequency of episodes of low back pain in these instructors and identify related factors. Material and method: Retrospective study involving 19 of the 23 WT instructors active in Spain. We have recorded the number of episodes of low back pain, professional background, paratrooper-activity and physical activity. In addition, we recorded instructors work sessions to identify postures, gestures and actions compatible with the production of mechanical low back pain. Results: 78.9% of instructors have suffered from back pain in the past year. We have not found significant differences in the presence of low back pain among the groups established from BMI, the number of hops throughout his career, hours per week in the WT and years as an instructor. There is no relationship with the practice of other physical activities. Using the video recording has been observed that, in the interior of the WT, instructors adopt all postures, gestures, and movements related to the production of non-specific low-back pain. All these activities act causing overloads muscle and joints. They are hyperlordosis, dorsal and lumbar kyphotic attitudes, transportation of cargos, maintenance of isometric contractions and twisting movements. Conclusions: There is a high incidence of low back pain in the WT instructors. The activities carried out by these professionals are risk for the production of mechanical back pain; therefore, it is necessary to create protocols of prevention of this problem (AU)
