Sample: the preclinical phase will be conducted in 20 healthy volunteers enrolled in the Faculty of Health Sciences of the University of Malaga. Clinical phase will take place in 12 subjects admitted to acute hospitalization in 'Costa del Sol' Health Agency and 12 subjects admitted to nursing homes in the District of Primary Knowing this information will identify different thresholds start in peripheral microcirculation disorders associated with various systems of body position and consequent pressure levels. This particular seems a reasonable need from baseline parameters allow to further explore specific situations of tissue injury and isolate direct and indirect causal factors. It is also necessary to conduct the study in subjects from different environments (home, hospital) to determine under real clinical practice how these parameters behave and how it can affect common procedures performed in clinical practice, such as repositioning or using pressure surfaces. This sample of 24 subjects was calculated taking into account a change in the capillary flow of 30% between baseline and the first hour of exposure to pressure, according to data of Kallman et al. (15) with an 80% output and statistical confidence level of 95%. In total, each subject will provide a total of 28 hours of measurement.