A gait stability investigation into FES-assisted paraplegic walking based on the walker tipping index

Abstract

The gait outcome measures used in clinical trials of paraplegic locomotor training determine the effectiveness of improved walking function assisted by the functional electrical stimulation (FES) system. Focused on kinematic, kinetic or physiological changes of paraplegic patients, traditional methods cannot quantify the walking stability or identify the unstable factors of gait in real time. Up until now, the published studies on dynamic gait stability for the effective use of FES have been limited. In this paper, the walker tipping index (WTI) was used to analyze and process gait stability in FES-assisted paraplegic walking. The main instrument was a specialized walker dynamometer system based on a multi-channel strain-gauge bridge network fixed on the frame of the walker. This system collected force information for the handle reaction vector between the patient's upper extremities and the walker during the walking process; the information was then converted into walker tipping index data, which is an evaluation indicator of the patient's walking stability. To demonstrate the potential usefulness of WTI in gait analysis, a preliminary clinical trial was conducted with seven paraplegic patients who were undergoing FES-assisted walking training and seven normal control subjects. The gait stability levels were quantified for these patients under different stimulation patterns and controls under normal walking with knee-immobilization through WTI analysis. The results showed that the walking stability in the FES-assisted paraplegic group was worse than that in the control subject group, with the primary concern being in the anterior-posterior plane. This new technique is practical for distinguishing useful gait information from the viewpoint of stability, and may be further applied in FES-assisted paraplegic walking rehabilitation.

Are older people putting themselves at risk when using their walking frames?

“…Most studies concerned with walking-aid-assisted mobility assessed standard gait parameters, for example [18][19][20][21], but without reporting on gait stability. Only a few studies focused on stable use of walking aids, and they interpreted movements and loading of the walking aid alone to then infer on the stability of the user [13,22,23]. This study significantly contributes to the existing literature as it provides a novel perspective to a previously under-researched issue: how older people use their walking frame in relation to a rigorous mechanical measure of stability, which considers the user and their device as a single system.…”

Wireless walker dynamometer design and static calibration based on ant colony system

“…If we let k be an ant located at state i , probability of the ant k making the transition from state i to state j was given by (6). where q ∈ [0, 1] was a random value, and q 0 ∈ [0, 1] was a constant. η ij , the visibility of state j from state i , was defined as This parameter η ij was utilised to prevent local convergence, which helped in approaching the optimal solution of the problem.…”

“…Voluntary mobility is an essential and important demand in activities of daily life for the paraplegic [1] and the elderly [2]. Furthermore, the level of mobility is a good indicator of health status [3].…”