Voluntary control of elbow extension significantly improves functional abilities for individuals with tetraplegia. As a result, surgical reconstruction of elbow extension via tendon transfer is considered a fundamental intervention that benefits the patient, even if other tendon transfers aimed at improving hand function are never performed. Presently, there are two common tendon transfer surgeries used to restore elbow extension following spinal cord injury. These are the posterior deltoid to triceps transfer and the biceps to triceps transfer. Both surgeries significantly improve voluntary elbow extension, although there is variability in the amount of control that is restored among patients. This study will directly compare the performance of the posterior deltoid transfer to the biceps transfer with regard to: voluntary elbow extension strength, the ability to activate the transfer, and neural factors associated with voluntary and involuntary control of individual muscles. These comparisons will be made in functionally relevant postures and will provide fundamental information that will improve clinical understanding of the capacity of each of these two procedures to restore elbow extension.