Ability of Near Infrared Spectroscopy to Isolate Compartments of the Extremity

Near infrared spectroscopy (NIRS) provides a non-invasive means of continuously monitoring
tissue oxygenation, which may be useful for diagnosis of acute compartment syndrome (ACS).
Placement of these sensor pads on the surface of the skin must be such that light penetrates
the intended compartment without inadvertently obtaining measurements of an adjacent
compartment. The objective of this study is to examine whether the NIRS measurements of each
compartment truly represent the tissue perfusion of the intended compartment, as indicated by
the predictable decrease in muscle oxygenation of a given compartment in response to muscle
fatigue. The investigators hypothesize that the tissue oxygenation values of the stimulated
compartment will significantly decrease following muscle stimulation, indicating that the
intended muscle compartment was successfully isolated. Additionally, the investigators
hypothesize that NIRS values of unstimulated muscle compartments will not change from
baseline.