The Kids STEP Study aims to

1. Determine if walking can be restored in children with incomplete SCI and little to no leg movement
2. Identify the neural pathways that permit recovery of walking

Locomotor training (LT) is an activity-based therapy to promote plasticity and recovery of walking. It is based on animal studies investigating walking recovery after spinal cord injury and the nervous system's control of walking. Normal walking is achieved through the interaction of multiple levels of the neural axis (cortex, brain stem, spinal cord). However, a basic rhythmic walking pattern is generated by central pattern generators (CPGs) located within the spinal cord. Investigations of central pattern generators indicate that sensory input specific to the task of walking can enhance the firing of these spinal neuronal centers. Thus, LT is an intensive walking program designed to provide sensory input to the spinal cord so that the neural output from the spinal CPGs can be maximized. In addition, LT uses a treadmill and a harness to provide partial body weight support enabling persons with injury to repetitively practice walking in a safe, enabling environment.

Children enrolled in the study (after medical clearance and consent to participate) will undergo extensive testing and complete 12 weeks of locomotor training. Testing will examine the child's neurologic and functional status. Tests to examine functional status include: ASIA evaluation of sensory and motor function, gait analysis, comprehensive strength tests, and assessment of skills such as cycling, stepping, and kicking. Tests to examine the child's neurologic injury include: MRI, Transcranial Magnetic Stimulation (TMS), and reflex testing. Locomotor training will be conducted daily (5 days/ week) for a total of 60 sessions over 12 weeks. During training children will work closely with therapists, researcher, and trainers to practice walking skills on the treadmill and over-ground.

Inclusion Criteria:

Individuals with SCI will include:

• Pre-adolescent children, ages 3-13 yrs old
• A diagnosis of first time, non-progressive SCI, upper motor neuron lesion, including, but not limited to, etiology from trauma, inflammation, vascular, surgical re-section due to localized tumor removal or orthopedic pathology resulting in clinical signs of lower cervical or thoracic spinal cord injury
• Non-ambulatory or impaired ambulation for greater than 1 yr, such that physical assistance and the use of assistive devices (i.e. walker) and/or leg braces (i.e. knee- ankle- foot orthoses (KAFOs)) are required to ambulate
• A SCI as defined by the American Spinal Injury Association (ASIA) Impairment Scale category B or C
• A medically stable condition that is asymptomatic for bladder infection, decubiti, osteoporosis, cardiopulmonary disease, pain, or other significant medical complications that would prohibit or interfere with testing of walking function and training or alter compliance with a training protocol
• Documented medical approval from the participant's personal physician verifying the participant's medical status
• Parent's informed consent for children

Exclusion Criteria

Children with SCI who -

• Are currently participating in a rehabilitation program or another research protocol that could interfere or influence the outcome measures of the current study
• Have a history of congenital SCI (e.g. Chiari malformation, myelomeningocele, intraspinal neoplasm, Frederich's ataxia) or other degenerative spinal disorders (e.g. spinocerebellar degeneration or syringomyelia) that may complicate the treatment and/or evaluation procedures
• Children who are diabetic or have implants, pacemakers, or devices which are not NMR/MRI compatible and are not suitable for the study

Children with SCI for whom walking recovery is unlikely