Experimental study of muscle permeability under various loading conditions

The permeability of a few muscle tissues under various loading conditions is characterized. To this end, we develop an experimental apparatus for permeability measurements which is based on the falling head method. We also design a dedicated sample holder which directs the flow through the tissue and simultaneously enables to pre-compress it. Although outside of the scope of this work, we recall that the permeability of the muscle has a crucial role in the pathophysiology of various diseases such as the compartment syndrome. Following the measurements of porcine, beef, chicken and lamb samples, we find that the permeability decreases with the pre-compression of the tissue. Similar decrease is observed following dehydration of the tissue. Remarkably, we find that within a physiological pressure range the permeabilities of the various samples are quite similar. This suggests that the muscle permeability is governed by a common micro-mechanical mechanism in which the blood propagates through the interstitial spaces. Under physiological loading conditions, the muscle permeability is in the range between 80 and 230 mm 4 N s .