The evaluation of and comparative evidence for two types of interventional devices for foot-drop of central neurological origin

Prenton, S

Abstract

Introduction
This thesis focusses on ankle foot orthoses (AFO) and functional electrical stimulation (FES) for the correction of foot-drop. It consists of two parts linked through identification of three gaps in the knowledge base: 1) limitations in device design, 2) limitations in device evaluation and 3) a lack of clear clinical guidance surrounding which of the two devices to use.
Methods and Results
PART 1 reports on the design and evaluation of an AFO alternative (dorsiflex sock) and an alternative to conventional FES systems (ShefStim®). Article 1 reports the evaluation of the researcher/user co-design approach used in the development of both devices, finding that lay-advisory involvement guided aspects such as where to locate the stimulator and informed the revision of the evaluation studies. Article 2 used a single case experimental design with 2 stroke participants to preliminarily explore the efficacy and user views of the dorsiflex sock. It found no clear evidence to demonstrate that the dorsiflex sock with its current design was effective, despite user views to the contrary.
Article 3 reported on the feasibility of ShefStim®. Seven current foot-drop FES users used ShefStim® unsupervised for two weeks at home, alongside gait laboratory testing of foot-clearance and kinematics at initial contact. Number of heel rises in day-day use was logged, as well as user satisfaction, donning/setup times and diary data. This data demonstrated that ShefStim® could be used in the community. Lab-based testing suggested that ShefStim® was comparable to conventional FES systems with regards kinematics at initial contact and foot-clearance. User satisfaction was comparable for both devices. However, further product refinement around setup and the electrode array-skin interface is necessary to make ShefStim® commercially viable. Article 4 reports on the design, development and evaluation of ShefStim®.
PART 2 comprises two meta-analyses focussing on orthotic (Article 5) and therapeutic (Article 6) effects. Article 5 revealed statistically comparable positive orthotic effects on walking speed, exercise capacity and the stroke impact scale. Article 6 found comparable therapeutic speed increases, but both reviews highlighted the lack of high quality evidence on use of each device outside of the laboratory. It was not possible draw any conclusions about the mechanisms-of-action underlying these findings.

Conclusion and future study
The dorsiflex sock and ShefStim® are both feasible devices and the novel approaches taken to their evaluation merit wider use in the field. Further work is necessary to improve the design of both devices before definitive clinical trials are carried out.
Despite AFO and FES showing similar levels of efficacy there is very little published work on the real world evaluation of either type of device or foot-drop specific mechanistic evaluations that might help to guide clinical choice. Therefore, this thesis highlights the need for further comparative randomised controlled trials, focussing on biomechanical and real world measures, informed by potential end-users.

Citation

Prenton, S. (in press). The evaluation of and comparative evidence for two types of interventional devices for foot-drop of central neurological origin. (Thesis). University of Salford

• Thesis Type: Thesis
• Acceptance Date: Mar 1, 2018
• Deposit Date: Apr 5, 2018
• Publicly Available Date: Apr 5, 2018
• Additional Information: Funders : University of Huddersfield