Long Term Split Belt Treadmill Training for Stroke Recovery

National Institutes of Health (NIH), National Institute on Aging (NIA), University of Maryland, VA Office of Research and Development

The purpose of this study is to determine whether split belt or conventional treadmill training can be used to treat walking pattern deficits from stroke and to determine whether this improves gait asymmetry and metabolic efficiency.

Coordination between the legs during walking is often disrupted after neurological injury, resulting in asymmetric gait patterns. Recent data shows that walking patterns can be altered through treadmill training, even after central nervous system damage. The investigators have studied short-term adaptation of inter-limb coordination during walking using a split-belt treadmill to control speed of the two legs independently. Our findings demonstrate that walking patterns are adaptable. The investigators have also shown that people with cerebral damage from stroke can benefit in the short-term to correct asymmetric walking patterns. Since all of our previous work has focused on single training sessions or up to 4 week training sessions, the investigators would like to study long-term effects of split belt treadmill training. Therefore, the purpose of this study is to prepare for a clinical trial of split-belt treadmill training to treat walking pattern deficits from cerebral damage. The investigators will gather data to determine whether different types of treadmill training on a custom split-belt treadmill are likely to change/improve walking symmetry as well as metabolic efficiency. The investigators will study adults with cerebral damage due to stroke. Subjects with hemiparesis will undergo training 3 times a week for a total of 33 training session. These 33 sessions will be broken into 3 blocks of 11 sessions. After each block of 11 sessions an evaluation will be done to record any gait improvements. Training for the subjects with hemiparesis will either be conventional treadmill walking (both legs moving at the same speed) or split-belt treadmill walking (with one leg moving faster than the other). These studies will provide important new information about normal mechanisms of locomotor adaptation, as well as providing a new rehabilitation tool for people with asymmetric gait patterns. Note that this study is not an aerobic conditioning program since subjects will work well below their age-adjusted target heart rate; it is instead a retraining program aimed at teaching people a new inter-limb coordination pattern as well as to determine whether this training can influence the subject's body's ability to use its intake of oxygen more efficiently. This study is also critical for developing procedural reliability processes, calculating effect sizes, training clinical staff, and determining other salient clinical variables in preparation for a randomized clinical trial.

A split belt treadmill is like a typical treadmill that is seen in the gym, except that this treadmill has two belts that move instead of just one. One leg goes on one belt and the other leg uses the other belt. The belt speeds can be set to move at the same speed, making this treadmill similar to any regular treadmill, but, belt speeds can also be set so that one belt moves a little faster than the other. The belts are never set at a running or jogging speed, only a self-paced walking speed regardless of whether the belts are both going the same or slightly different speeds.

Change in Baseline Step Length Symmetry. That is, Whether the Steps With Right and Left Legs Are the Same Length.

Subjects will either walk on a special mat that records their step lengths, or will wear special markers on the feet and body to record their step lengths.

This is the change in metabolic power that is required of a subject to walk at their self selected walking speed on the treadmill. Metabolic power was measured at baseline, post training, and three months after training. We report the difference between post training and baseline and three months and baseline.

Subjects walked on an electronic walkway and walking speed was calculated by total distance divided by total time.

Inclusion Criteria: stroke or hemiparesis (>6 months post stroke) able to walk but has residual gait deficit (including those who walk with a cane or walker) This is their first and only stroke Able to walk for 5 minutes at their self-paced speed Adults age 20-80 Exclusion Criteria: Cerebellar signs (e.g.ataxic hemiparesis) Any neurologic condition other than stroke Insulin dependent diabetes Congestive heart failure Peripheral artery disease with claudication Pulmonary or renal failure Unstable angina Uncontrolled hypertension (>190/110 mmHg) Dementia Severe aphasia Orthopedic or pain conditions that limit walking Total joint replacement in the lower extremities Pregnancy