A method includes affixing a co-planar sensor on a surface, using a processor, and providing an output. The method includes affixing a co-planar sensor on a surface at a first tissue site. The sensor has a force transducer disposed at an aperture of a rigid guard member. The guard member and the transducer are in co-planar alignment. The transducer is configured to provide an electrical signal corresponding to an internal pressure at the first tissue site. The method includes using the processor to compare the internal pressure with a reference value. Based on the comparison, the method includes providing an output corresponding to compartment syndrome at the first tissue site.
