The purpose of the study is to evaluate whether non-invasive stimulation over the spinal cord at the neck and/or lower back can improve walking function for people with neurologic conditions. Spinal stimulation has been used extensively for individuals with spinal cord injury, and has demonstrated improvements in function. This study will extend this work to other neurologic conditions, such as cerebral palsy and stroke, that also demonstrate similar impairments as spinal cord injury. The primary aims of this study are to: Aim 1: Evaluate impact of spinal stimulation on spasticity and locomotor function. Aim 2: Investigate participant perceptions of spinal stimulation. The investigators will be using a cross-over design study to compare intensive training only to intensive training combined with spinal stimulation. After an initial baseline period of up to 4 weeks (Phase I). Participants will have their first intervention phase of the study (Phase II). This will involve either intensive training only (Condition A) or intensive training combined with spinal stimulation (Condition B). This will be followed by a washout period with no intervention (Phase III) and then the second intervention phase (Phase IV). The second intervention phase will involve either Condition A or Condition B, whichever the participants did not received during Phase II. Phases II-IV will each last up to 8 weeks. After the intervention period is complete, the participant will be asked to come for follow-up visits up to 3 months after the intervention phases are completed (Phase V).