Development of Low Cost Devices to Increase Access to Treadmill Training

The investigators will develop and assess the use of spring-loaded devices to assist limb swing and forward propulsion during body weight supported treadmill training (BWSTT) (Aim 1). Prototype models of both devices have been developed.

These devices will be:

• simple to use in the clinical setting;
• will be easily adjustable to alter the assistance provided; and,
• will be able to quantify the amount of assistance necessary to facilitate normal stepping patterns.

The investigators will also evaluate short- and long-term adaptations in locomotor performance following BWSTT in individuals with incomplete SCI with the use of these devices. This information will identify the effects of variable assistance at the limbs or trunk to modulate muscle activity and/or motor performance (kinematics) during stepping to maximize walking recovery.

Inclusion criteria

• non-progressive lesion between spinal levels C1-T10 of > 3 months duration. Subjects with below T10 will be excluded due to potential lower motor neuron (LMN) injury
• score > 10 on the Lower Extremity Motor Score (LEMS) developed previously to measure strength in SCI. For the LEMS criteria, preliminary data indicate that subjects with LEMS < 10 in the chronic stages do not recover walking
• All subjects must require physical assistance to ambulate on the treadmill at a speed of 4.0 kmph at 0% body weight support (BWS)
• All subjects will have an overground gait speed <.8m/s
• range of motion (ankle: -10 to 30 deg, knee: 0 to 90 deg, hip: -10 to 40 deg) consistent with gait
• medically stable with medical clearance to participate (absence of concurrent illness, including unhealed decubiti, infection, cardiopulmonary disease, osteoporosis, active heterotrophic ossification or peripheral nerve damage in the lower limbs, history of traumatic head injury)
• able to tolerate 30 minutes of upright (standing) position without orthostasis (decrease in blood pressure by 20 mmHg systolic and 10 mmHg diastolic; minimized with ambulatory population)
• women of childbearing potential

Exclusion criteria

• women who are pregnant will be excluded due to potential forces at trunk from BWS or pelvic assistance
• those in concurrent physical therapy to eliminate effects of additional interventions