Muscle atrophy and neuromuscular impairment are consequences of spinal cord injury (SCI) that impede quality of life and functional recovery. While it is known that SCI causes negative morphological and contractile effects on the muscle, dynamic changes in mechanisms that contribute to the catabolic processes are still largely unknown. Characterization of acute to chronic temporal muscle changes following SCI is necessary to determine the physiological effects in individuals who suffer from chronic moderate to severe SCI contusion. Additionally, establishing pathways that undergo significant changes in response to SCI is needed to serve as a foundation for potential treatment of SCI-induced muscle atrophy. The primary goal of this proposal is to examine time course changes in muscle function, morphology, and molecular mechanisms underlying muscle pathology occurring in rats in response to moderate-severe contusion SCI.