Time-Discrete Vibrotactile Feedback Contributes to Improved Gait Symmetry in Patients With Lower Limb Amputations: Case Series

BACKGROUND: Reduced sensory feedback from lower leg prostheses results in harmful gait patterns and entails a significant cognitive burden because users have to visually monitor their locomotion.

OBJECTIVES: The purpose of this study was to validate a sensory feedback device designed to help elderly patients with transfemoral amputation to improve their temporal gait symmetry after a training program aimed at associating the vibrotactile patterns with symmetrical walking.

DESIGN: This was a prospective quasi-experimental study including 3 elderly patients walking with lower leg prostheses.

METHODS: During training sessions, participants walked on a treadmill equipped with a feedback device that controlled vibrotactile stimulators based on signals from a sensorized insole while provided with visual feedback about temporal gait symmetry. The vibrotactile stimulators delivered short-lasting, low-intensity vibrations synchronously with certain gait-phase transitions. During pretraining and posttraining sessions, participants walked without visual feedback about gait symmetry under 4 conditions: with or without vibrotactile feedback while performing or not performing a secondary cognitive task. The primary outcome measure was temporal gait symmetry.

RESULTS: With ≤2 hours of training, the participants improved their temporal gait symmetry from 0.82 to 0.84 during the pretraining evaluation session to 0.98 to 1.02 during the follow-up session across all conditions. Following training, participants were able to maintain good temporal gait symmetry, without any evidence of an increased cognitive burden.

LIMITATIONS: The small sample size and short follow-up time do not allow straightforward extrapolations to larger populations or extended time periods.

CONCLUSIONS: Low-cost, gait phase-specific vibrotactile feedback, after training combined with visual feedback, may improve the temporal gait symmetry in patients with transfemoral amputation without representing an additional cognitive burden.