Increased Symmetry of Lower-Limb Amputees Walking With Concurrent Bilateral Vibrotactile Feedback

Abstract

Gait asymmetry in lower-limb amputees can lead to several secondary conditions that can decrease general health and quality of life. Including augmented sensory feedback in rehabilitation programs can effectively mitigate spatiotemporal gait irregularities. Such benefits can be obtained with non-invasive haptic systems representing an advantageous choice for usability in overground training and every-day life. In this study, we tested a wearable tactile feedback device delivering short-lasting (100 ms) vibrations around the waist syncronized to gait events, to improve the temporal gait symmetry of lower-limb amputees. Three above-knee amputees participated in the study. The device provided bilateral stimulations during a training program that involved ground-level gait training. After three training sessions, participants showed higher temporal symmetry when walking with the haptic feedback in comparison to their natural walking (resulting symmetry index increases of +2.8% for Subject IDA, +12.7% for Subject IDB and +2.9% for Subject IDC). One subject retained improved symmetry (Subject IDB, +14.9%) even when walking without the device. Gait analyses revealed that higher temporal symmetry may lead to concurrent compensation strategies in the trunk and pelvis. Overall, the results of this pilot study confirm the potential utility of sensory feedback devices to positively influence gait parameters when used in supervised settings. Future studies shall clarify more precisely the training modalities and the targets of rehabilitation programs with such devices.

Design and Validation of a Real-Time Visual Feedback System to Improve Minimum Toe Clearance (mTC) in Transfemoral Amputees

“…Here, our goal is to design and implement an intuitive biofeedback environment that is capable of Design and validation of a real-time visual feedback system to improve minimum toe clearance (mTC) in transfemoral amputees T enhancing the toe clearance in transfemoral amputee in a much conducive manner. In the past, motor learning during biofeedback training has shown a positive outcome during gait and balance performance [16], [17]. Visual feedback during gait training has shown a promising effect on various gait mobility outcomes, with significant research focusing on the gait symmetry improvements and balance recovery in amputees and healthy individuals [18]- [20].…”

Context expectation influences the gait pattern biomechanics

“…17 ; see also Ref. 43 for a preliminary rehabilitative application in lower-limb amputees). Our study extends these findings showing a more coherent and pervasive effect not only on spatio-temporal, but also on kinetic, and kinematic parameters.…”

“…For example, active exoskeleton and brain-computer interface methodologies continuously deal with technical, technological, and theoretical challenges. Intention decoding (e.g., to start walking vs. to stop walking; to start walking on the grass vs. to start walking on the asphalt) represents one of the most urgent challenges in this domain 64 , being strictly related to safety and usability of these neurotechnologies 43,63,65 . Our study suggests that priors and expectations should be also considered in the complex picture composing the intention decoding issue for walking.…”

A review of user needs to drive the development of lower limb prostheses

“…In addition to improvements in the control of prosthetic devices, artificial sensory feedback has been shown to address some of the user needs. These include increased gait symmetry [ 185 , 186 ], embodiment [ 148 ], reduced phantom limb pain [ 59 , 166 ], and reduced weight perception [ 149 ]. With the further development and tuning of feedback parameters, these aspects could be potentially improved even more.…”