title: 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.
authors.affiliation: Department of Biomedical Engineering, College of Precision Instruments and Optoelectronics Engineering, Tianjin University, Tianjin, People's Republic of China. richardming@tju.edu.cn
authors.forename: Dong
authors.initials: D
authors.lastname: Ming
authors.forename: Yanru
authors.initials: Y
authors.lastname: Bai
authors.forename: Xiuyun
authors.initials: X
authors.lastname: Liu
authors.forename: Hongzhi
authors.initials: H
authors.lastname: Qi
authors.forename: Longlong
authors.initials: L
authors.lastname: Cheng
authors.forename: Baikun
authors.initials: B
authors.lastname: Wan
authors.forename: Yong
authors.initials: Y
authors.lastname: Hu
authors.forename: Yatwa
authors.initials: Y
authors.lastname: Wong
authors.forename: Keith D K
authors.initials: KD
authors.lastname: Luk
authors.forename: John C Y
authors.initials: JC
authors.lastname: Leong
mesh_terms: D000328:Adult; D000465:Algorithms; D001132:Arm / Q000502:physiology; D001696:Biomechanical Phenomena; D004185:Disability Evaluation; D004599:Electric Stimulation Therapy / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008962:Models, Theoretical; D010264:Paraplegia / Q000503:physiopathology* / Q000628:therapy*; D010865:Pilot Projects; D004856:Postural Balance; D014853:Walkers; D016138:Walking / Q000502:physiology*