Runners' responses to a biofeedback intervention aimed to reduce tibial acceleration differ within and between individuals.

An increment in peak tibial acceleration (PTA) may be related to an increased risk of running-rated injury. Many authors believe that reducing PTA through improved shock-absorption could, therefore, help prevent injury. The aim of the current study was, therefore, to investigate the individual responses of participants to a biofeedback intervention aimed at reducing PTA.11 participants (two females, nine males; 43 ±â€¯10 years; stature: 1.74 ±â€¯0.07 m; body mass: 74 ±â€¯11 kg; distance running a week: 19 ±â€¯14 km; 5 km time: 24 ±â€¯3 min) received an intervention of six sessions of multisensory biofeedback aimed at reducing PTA. Mean PTA and kinematic patterns were measured at baseline, directly after the feedback intervention and a month after the end of the intervention. Group as well as single-subject analyses were performed to quantify differences between the sessions. A significant decrease of 26 per cent (effect size: Hedges' g = 0.94) in mean PTA was found a month after the intervention. No significant changes or large effect sizes were found for any group differences in the kinematic variables. However, on an individual level, shock-absorbing solutions differed both within and between participants. The data suggest participants did not learn a specific solution to reduce PTA but rather learned the concept of reducing PTA. These results suggest future research in gait retraining should investigate individual learning responses and focus on the different strategies participants use both between and within sessions. For training purposes, participants should not focus on learning one running strategy, but they should explore several strategies.

The use of biofeedback for gait retraining: A mapping review.

BACKGROUND: Biofeedback seems to be a promising tool to improve gait outcomes for both healthy individuals and patient groups. However, due to differences in study designs and outcome measurements, it remains uncertain how different forms of feedback affect gait outcomes. Therefore, the aim of this study is to review primary biomechanical literature which has used biofeedback to alter gait-related outcomes in human participants. METHODS: Medline, Cinahl, Cochrane, SPORTDiscus and Pubmed were searched from inception to December 2017 using various keywords and the following MeSHterms: biofeedback, feedback, gait, walking and running. From the included studies, sixteen different study characteristics were extracted. FINDINGS: In this mapping review 173 studies were included. The most common feedback mode used was visual feedback (42%, n = 73) and the majority fed-back kinematic parameters (36%, n = 62). The design of the studies was poor: only 8% (n = 13) of the studies had both a control group and a retention test; 69% (n = 120) of the studies had neither. A retention test after 6 months was performed in 3% (n = 5) of the studies, feedback was faded in 9% (n = 15) and feedback was given in the field rather than the laboratory in 4% (n = 8) of the studies. INTERPRETATION: Further work on biofeedback and gait should focus on the direct comparison between different modes of feedback or feedback parameters, along with better designed and field based studies.

A review of the design and clinical evaluation of the ShefStim array-based functional electrical stimulation system.

Functional electrical stimulation has been shown to be a safe and effective means of correcting foot drop of central neurological origin. Current surface-based devices typically consist of a single channel stimulator, a sensor for determining gait phase and a cuff, within which is housed the anode and cathode. The cuff-mounted electrode design reduces the likelihood of large errors in electrode placement, but the user is still fully responsible for selecting the correct stimulation level each time the system is donned. Researchers have investigated different approaches to automating aspects of setup and/or use, including recent promising work based on iterative learning techniques. This paper reports on the design and clinical evaluation of an electrode array-based FES system for the correction of drop foot, ShefStim. The paper reviews the design process from proof of concept lab-based study, through modelling of the array geometry and interface layer to array search algorithm development. Finally, the paper summarises two clinical studies involving patients with drop foot. The results suggest that the ShefStim system with automated setup produces results which are comparable with clinician setup of conventional systems. Further, the final study demonstrated that patients can use the system without clinical supervision. When used unsupervised, setup time was 14min (9min for automated search plus 5min for donning the equipment), although this figure could be reduced significantly with relatively minor changes to the design.

Feasibility study of a take-home array-based functional electrical stimulation system with automated setup for current functional electrical stimulation users with foot-drop.

OBJECTIVE: To investigate the feasibility of unsupervised community use of an array-based automated setup functional electrical stimulator for current foot-drop functional electrical stimulation (FES) users. DESIGN: Feasibility study. SETTING: Gait laboratory and community use. PARTICIPANTS: Participants (N=7) with diagnosis of unilateral foot-drop of central neurologic origin (>6mo) who were regular users of a foot-drop FES system (>3mo). INTERVENTION: Array-based automated setup FES system for foot-drop (ShefStim). MAIN OUTCOME MEASURES: Logged usage, logged automated setup times for the array-based automated setup FES system and diary recording of problems experienced, all collected in the community environment. Walking speed, ankle angles at initial contact, foot clearance during swing, and the Quebec User Evaluation of Satisfaction with Assistive Technology version 2.0 (QUEST version 2.0) questionnaire, all collected in the gait laboratory. RESULTS: All participants were able to use the array-based automated setup FES system. Total setup time took longer than participants' own FES systems, and automated setup time was longer than in a previous study of a similar system. Some problems were experienced, but overall, participants were as satisfied with this system as their own FES system. The increase in walking speed (N=7) relative to no stimulation was comparable between both systems, and appropriate ankle angles at initial contact (N=7) and foot clearance during swing (n=5) were greater with the array-based automated setup FES system. CONCLUSIONS: This study demonstrates that an array-based automated setup FES system for foot-drop can be successfully used unsupervised. Despite setup's taking longer and some problems, users are satisfied with the system and it would appear as effective, if not better, at addressing the foot-drop impairment. Further product development of this unique system, followed by a larger-scale and longer-term study, is required before firm conclusions about its efficacy can be reached.