The primary goal of the proposed study is to identify the contributions of the amount of task-specific practice on locomotor (i.e., walking) recovery in patients with chronic (> 1 yr) motor incomplete spinal cord injury (iSCI). Consistent with principles of motor learning and exercise physiology, the investigators contend that certain training (i.e., dosage) parameters of physical rehabilitation are critical to mobility outcomes following neurological injury. Specifically, the specificity, amount and intensity of physical interventions (i.e., practice) may influence specific outcomes in the patient population treated. In ambulatory patients with iSCI, there are very few studies that have controlled for or targeted these training variables or their influence on locomotor recovery. Previous work suggests these training parameters may influence locomotor recovery in patients with other neurological disorders (i.e., stroke), although few studies have attempted to delineate similar contributions of in iSCI. Indeed, no studies have carefully controlled the amount of task-specific practice during physical rehabilitation of patients with iSCI, and such interventions are rarely utilized in the clinical setting. The goal of the present study is to delineate the relative contributions of amount of task-specific training on locomotor outcomes in individuals with iSCI. Using a cross-over, randomized clinical trial design, the investigators anticipated non-specific (i.e., non-stepping) training activities would result in smaller improvements as compared to task-specific (stepping) training. The investigators will investigate the effects of such training on walking performance and kinematics, as well as the impairments thought to contribute to walking performance. Successful completion of this project could have an immediate impact on rehabilitation research and treatment of people following iSCI, and may be utilized to treat more subacute patients with iSCI or other acute-onset neurological disorders.