IMPROVED GAIT AND ELEVATION SPEED OF INDIVIDUALS POST-STROKE AFTER LOWER EXTREMITY TRAINING IN VIRTUAL ENVIRONMENTS.

Abstract

PURPOSE/HYPOTHESIS: The purpose of this study was to determine if lower extremity training in virtual reality (VR) transferred to improved gait and elevations speeds. We hypothesized that selected individuals post-stroke would improve their walking and elevations speeds after VR training. NUMBER OF SUBJECTS: Six individuals 9 months to 8 years post-stroke (1 female and 5 males) ages 41-81 participated in the study. All individuals ambulated independently. Three used either an assistive device or a brace. Their walking speeds ranged from .14 ft/sec to .88 ft/sec. MATERIALS/METHODS: Study design was a double baseline pre-post-test. A robotic device (the Rutgers Ankle) was the input to the virtual environment (VE). Participants, who were seated, used the movements of their affected foot to control a plane or a boat in the VE, which was displayed on a desktop computer. Their task was to navigate in the VE through a series of targets without contacting them. Parameters such as range of motion, platform resistance and speed of targets were adjusted to create warm up, endurance, speed, strengthening and coordination exercises. Perturbations were created using haptic (sensation) effects and changing visibility in the VE. Subjects trained three times a week for four weeks. Primary outcome measures included gait and elevation speed. Primary clinical outcome variables were gait speed (measured as the average of three walking trials collected on the Gait Rite), endurance (six minute walk test) and elevation speed (time to ascend and descend two flights of steps). Training effects were assessed using paired t-tests with the two baselines averaged. RESULTS: Gait speed increased 11% from .64 ft/sec. to .71 ft/sec (p=.08) and elevation time decreased 14% from 27 to 23 seconds (p=.05). Gait endurance increased 11% from 800 to 891 feet/6 minutes (NS). Gait speed improvements ranged from 0 to 44%. Elevation speed improvements ranged from 3-33%. CONCLUSIONS: Improved gait and elevation speed as well as gait endurance were made by a group of chronic post-stroke individuals. Variability in the amount of improvement observed indicates that the training was more effective for some of the participants. Frequency and duration of treatments were similar however, training intensity varied based on participant's ability. CLINICAL RELEVANCE: Individuals post-stroke from a broad age range were able to train lower extremity movements in a virtual environment with a transfer to the real world. The training intensity achieved in VR may be related to the transfer of improvements. This is preliminary evidence that VR may be a viable adjunct for gait training of selected individuals post-stroke.