Institut für Luft- und Raumfahrtmedizin Assessment of capillary blood volume and oxygenation in unloaded Lower leg muscles during whole body vibration ‐VOV‐Study‐ Before you apply as a participant in the VOV study, we would like to provide you with more information about the purpose and content of the study. 1. Scientific Background The physiological effects of whole body vibration (WBV) training have been subject of several studies during the last decade. WBV has always been applied in combination with resistive static or dynamic exercise, which was at minimum weight bearing during upright standing. The effects of the mechanical stress and the complex afferent input by mere WBV without additional voluntary contraction is not known so far. When vibration is added to an isometric or dynamic muscle load, the leg muscles react with an increase in EMG activity and an increase in energy turn‐over. Moreover, during vibration muscle converts part of the absorbed kinetic energy into heat. Muscle hypoxia is the major stimulus for the gradual arterial vasodilation by which muscle increases its oxygen supply during exercise. However, it is still under discussion whether during exercise mechanical impacts on erythrocytes or the endothelia may also activate the release of metabolites like ATP or NO, respectively, which are involved in the decrease of vascular tone. In this new study we test the whether the ejection of venous blood from the lower leg by acceleration is driven by the acceleration of the mass of blood by vibration which requires a vibration motion in parallel with main direction of vessels in the muscle which is the length axis of the leg. 2. Implementation of the Study In the VOV study, there will be 18 male subjects that participate in all parts of the experiment. All measurements will be taken at the Deutsches Zentrum für Luft‐ und Raumfahrt (DLR) in Köln. Overall, the VOV study will consist of 3 visits total to DLR. The first visit will include a medical check‐up. Then, if the subjects are deemed eligible for the study, they will participate in the main study. In the first day of measurement, the vibration will be applied to subjects either in parallel or in orthogonal direction with the length axis of the legs. The body will be tilted at three different angles (Figure‐1). In the second visit vibration will be applied in orthogonal direction to first day and during in the same three body postures. . The direction of vibration on the first day and the order of tilt angles will be randomized between subjects. All the physiological examinations will be noninvasive (surface electromyography, near infrared spectroscopy, ultrasound measurement). The studies will be conducted during the term mid‐June and pre‐September, 2014 (exact dates and schedule will be provided if the subject is chosen to participate in the study). Figure 1: In the VOV study the subjects will be exposed to vibration during different tilting angles.
© Copyright 2024 ExpyDoc
