The goal of this study is to determine if training in both the forward and reverse modes on the ICARE (motor-assisted elliptical) contributes to improvements in gait and cardiorespiratory fitness.

A growing number of facilities are using the robotic ICARE, a motor-assisted elliptical, to improve walking and fitness in individuals with physical disabilities. The device promotes movements emulating the joint motions and muscle demands of normal gait and integrates design features that improve accessibility and usability (e.g., motor assistance, partial BWS, electronic height-adjustable seat, steps, ramp, wheelchair platform) compared to traditional ellipticals. A motor assists those with strength and/or endurance limitations to train (forward/reverse directions) at speeds up to 65 cycles per minute (CPM), thus creating opportunities for the mass repetition of a gait-like movement pattern that is often advocated as critical for behavioral and neurologic recovery. Individuals can over-ride the motor's assistance simply by training faster than the set speed. Documented improvements in walking and cardiorespiratory fitness in individuals with neurologic injuries and illnesses following an ICARE training program in the forward direction are promising.

Reverse walking is one method clinicians have used to improve forward walking performance in patients with various neurological disorders. Although the ICARE allows for reverse training, and this feature has been used clinically, no studies to date have compared changes in walking and cardiorespiratory fitness arising from an ICARE training intervention performed in the reverse direction to those arising from an ICARE intervention performed in the forward direction. Thus, the purpose of this exploratory study is to compare gait and cardiorespiratory improvements arising from blocks (12-sessions) of forward vs. reverse ICARE training in participants with walking dysfunction. For this exploratory study, the investigators hypothesize that both forward and reverse training will contribute to improvements in gait and cardiorespiratory fitness. In addition, the investigators seek to understand whether the magnitude of change will differ between each form of training (i.e., forward vs. reverse) and whether the order of training will impact the magnitude of change (i.e. block of 12-sessions forward followed by block of 12-sessions reverse vs. block of 12-sessions reverse followed by block of 12-sessions forward). Measurements will be recorded immediately prior to intervention initiation (T0), following completion of the first training block (T1), immediately following completion of the second training block (T2), and 3 months following completion of the second training block (T3)

Inclusion Criteria:

• Walking dysfunction from a neurologic injury or illness (e.g. stroke, brain injury, incomplete spinal cord injury, multiple sclerosis, Parkinson's disease, cerebral palsy);
• Able to stand (with or without a standing frame) for at least 5 minutes at a time;
• Able to follow simple commands; and
• Possess adequate judgment or communication skills to safely use the ICARE trainer.

Exclusion Criteria:

• Currently enrolled in an existing physical or occupational therapy program or an exercise program for their legs;
• Orthopedic conditions (such as bone fractures/breaks) that haven't healed;
• Unstable cardiac or respiratory conditions that would prohibit safe exercise;
• Pregnant or think they may be pregnant, given unknown but potential risk of vigorous exercise to the mother and/or the unborn fetus; and/or
• Experience self-reported pain that inhibits walking/exercise ability.

There is no plan for sharing IPD.