Twin Star Medical has developed a novel Compartment Monitoring System (CMS) that consists of a pressure monitoring module and two types of catheters. Both Twin Star Catheters remove interstitial tissue fluid, which may contribute to a reduction in compartment pressure, and which may be used for clinical analysis to determine if certain analyte indicators of muscle injury (biomarkers) can be predictive of CS development. One type of catheter Pressure Measurement/Fluid Collection, (PMFC), removes fluid and monitors pressure via a solid-state fiber optic transducer at the tip of the catheter. The other type of catheter, Fluid Collection (FC), only removes fluid and does not have a pressure transducer at the tip. The monitoring module senses, displays and records pressure as measured by the PMFC catheter as well as provides a vacuum source, which is required for the operation of the fluid removal catheter. The Twin Star CMS Monitoring Module has been successfully tested to (1) ensure the delivery of the specified functional performance requirements needed to reliably operate the Twin Star Catheter, and (2) meet current electrical safety standards established for clinical use. The first model of the Twin Star catheter and monitor was reviewed and approved by the Food and Drug Administration (FDA) for the indications of pressure measurement and the withdrawal of interstitial fluid. The devices being used for this clinical study represent the newly designed catheter and monitor and are not FDA approved and are therefore considered investigational. It is anticipated that the second-generation model of the catheter and monitor will be submitted to the FDA for approval while this study is being conducted.