Improving Stepping-Over Responses in the Elderly using Simulated Objects


Principal Investigators: David L. Jaffe, MS and David A. Brown, PhD, PT (Northwestern University)

Project Staff: Cheryl D. Pierson-Carey, MS, PT; Ellie L. Buckley, MS PT; Ruth Yap, MS; and Kyle A. Smith, MPT, ATC

Project Category: Stroke - 2001

Objective: The long term goal of this work was to apply and evaluate a system for individuals with stroke that trains, monitors, and improves their walking characteristics including stride length, walking speed, balance, ability to step over objects, and endurance. The proposed method was expected to be safer and physically more compact than conventional training techniques and to provide more rapid and precise feedback to both the patient and the clinician.

Research Plan: This project compared two training interventions: stepping over real foam objects (Overground) and stepping over computer-generated objects (Treadmill). The latter protocol consists of a computer simulated environment: computer generated objects are presented in a head-mounted display, superimposed on a real-time side view of the subject walking on a treadmill. "Collisions" between the users' feet and the computer-generated obstacles are detected using a commercial computer imaging system with vibro-tactile feedback given to the "colliding foot". The combination of visual, audio, tactile feedback, and advice from a physical therapist promoted more effective walking strategies with stroke patients. Gait parameters were monitored before training, after training, and two-weeks post-training.

Work Accomplished: Twenty-one subjects with stroke were enrolled in the two-week training program. Subject data has been analyzed to identify gait improvements with the two training techniques.

Expected Outcome: The results demonstrated improvements for subjects in both training groups in walking speed, cadence, stride length, and ability to step over stationary objects. Treadmill intervention data from subjects with stroke in the study show significantly increased walking speed and stride length measures for both normal and fast walking evaluation tests. Eighty to 95% of these improvements were retained two weeks after the end of the training.

This project demonstrated that training individuals with stroke to step over objects improves their gait parameters which, in turn, led to increased walking speed and confidence.

A Report of Invention has been submitted to the VA and the Stanford Office of Technology Licensing for this project. This will start the process of patenting the Treadmill training technique and possible commercialization. Collaborations with other researchers are being pursued.

Funding Source: VA RR&D Merit Review

Funding Status: Completed

Reprinted from the 2001 Annual Report