Long Term Split Belt Treadmill Training for Stroke Recovery

• Change in Baseline Step length symmetry. That is, whether the steps with right and left legs are the same length. [ Time Frame: Baseline Visit 1 (week 1) and Baseline Visit 2 (week 2), 2 times during training (once at week 6 and once at week 10), after training (week 14), and 1- and 3 months after training ] [ Designated as safety issue: No ]
  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.
  
  

• Change in Baseline Oxygen intake [ Time Frame: Baseline Visit 1 (week 1) and Baseline Visit 2 (week 2), 2 times during training (once at week 6 and once at week 10), after training (week 14), and 1- and 3 months after training ] [ Designated as safety issue: No ]
  A metabolic cart will be used while the subject is walking on the treadmill to determine if training is helping their bodies become more efficient with their oxygen intake.
  
  
• Walking speed [ Time Frame: Before training, periodically during training, post training and 1- and 3 months after training ] [ Designated as safety issue: No ]
  Subjects will complete a 6 meter walking test to determine if the treadmill training has increased their walking speed. This will allow for a progressive increase in treadmill speed during training for each individual subject.
  
  

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.