unable to hire qualified personnel to run the study

Recent research in gait training for stroke survivors showed that coordinated gait components can be best restored using the following interventions together: coordination exercises, over ground gait training, and body weight supported treadmill training (BWSTT). These results are important because, to the investigators' knowledge, there have been no other reports of the restoration of coordinated gait components for those with persistent gait deficits (> 6 months after stroke). However, a remaining problem was that the restored coordinated gait movements measured in the laboratory did not generalize for many subjects to the everyday environment. The confluence of several factors can cause lack of generalization. First, dual task performance (gait and cognitive attention task) can degrade both gait and attention ability, even in healthy adults. Second, stroke can impair attention. Third, during walking in the everyday environment, attention is required in order to safely process normally occurring stimuli. Therefore, given the success of the new gait training protocol in the lab setting, it is important to address the problems remaining for generalization of the recovered coordinated gait pattern to the everyday environment. The primary hypothesis of this study is that greater gains in gait speed will be produced by combined motor and cognitive training versus motor training alone.

Aim 1, Hypothesis Ia: Comparison of combined motor and cognitive training vs motor training alone. For Aim 1, Hypothesis Ia, this will be a randomized, controlled study. For the two groups, 38 subjects will be enrolled and randomized to either: A) Motor + Cognitive Training; or B) Motor Training alone. Subjects will first be stratified according to coordination and gait deficit severity, as described below. After stratification, the subject will be randomized to one of the two intervention groups for Hypothesis Ia. All the subjects will receive treatment 5 times/week, 3hrs/session, for 12 weeks or for a total of 60 treatment sessions. Group A will receive combined motor and cognitive training; Table 2 (below) shows the graduated approach to providing combined gait and cognitive training. Data collection will be at weeks 1, 6, 12, and 24 (i.e., before, mid-treatment and after treatment, and then 3 months after the end of the treatment protocol. Comparison will be made between the two groups to determine whether there was any additive effectiveness of the cognitive training.

Aim 2, Hypotheses IIa-d: Pre/post-treatment comparisons within Group A, receiving combined motor and cognitive training. For Aim 2, Hypotheses IIa-d, this will be a single cohort pre/post-treatment comparison within Group A receiving combined motor and cognitive training.

Aim 3, Hypotheses IIIa-d: Pre/post-treatment comparisons within Group B, receiving motor training alone. For Aim 3, Hypotheses IIIa-d, this will be a single cohort pre/post-treatment comparison within Group B, receiving motor training alone.

Inclusion Criteria:

Stroke Survivor inclusion/exclusion criteria Inclusion Criteria

• Cognition sufficiently intact to give valid informed consent to participate. *
• Sufficient endurance to participate in rehabilitation sessions.
• Ability to follow 2 stage commands.
• Medically Stable
• Age > 21 years.
• Impaired ambulation as follows: inability to flex the knee and ankle in the sagittal plane, in a normal manner so the foot clears the floor; inability to control normal knee angle during single limb weight bearing during stance phase.
• At least 6 months post stroke.

Able-bodied Inclusion criteria

• Criteria to be included is that they should be healthy with no history of a neurological disease or orthopedic impairment.**
• Not Pregnant.
• No Claustrophobia (only for the sub-sample asked to undergo fMRI.)
• No counterindications to MR scanning including, pregnancy, weight inappropriate for height, ferrous objects within the body (only for the sub-sample asked to undergo fMRI.)

Exclusion Criteria:

Exclusion Criteria

• Acute or progressive cardiac, vascular, renal, respiratory, neurological disorders or malignancy.
• Active psychiatric diagnosis or psychological condition, or active drug/alcohol abuse.
• Lower motor neuron damage or radiculopathy.
• Orthopedic impairment. **
• More than one stroke.
• Cerebellar dysfunction.
• Fugl-Meyer lower limb motor sub-score greater than 32.
• No simultaneous gait rehabilitation participation.
• Pregnant.
• Claustrophobia (only for the sub-sample asked to undergo fMRI.)
• Criteria specific to MR scanning, including pregnancy, weight inappropriate for height, ferrous objects within the body (only for the sub-sample asked to undergo fMRI.)

Early closure leading to small numbers of subjects analyzed. early enrollment closure due to inability for the institution to hire skilled clinicians in a timely manner in order to enroll and treat participants in the available time frame.