Functional electrical stimulation versus ankle foot orthoses for foot-drop: a meta-analysis of orthotic effects

Objective: To compare the effects on walking of Functional Electrical Stimulation (FES) and Ankle Foot Orthoses (AFO) for foot-drop of central neurological origin, assessed in terms of unassisted walking behaviours compared with assisted walking following a period of use (combined-orthotic effects). Data Sources: MEDLINE, AMED, CINAHL, Cochrane Central Register of Controlled Trials, Scopus, REHABDATA, PEDro, NIHR Centre for Reviews and Dissemination and clinicaltrials.gov. plus reference list, journal, author and citation searches. Study Selection: English language comparative Randomised Controlled Trials (RCTs). Data Synthesis: Seven RCTs were eligible for inclusion. Two of these reported different results from the same trial and another two reported results from different follow up periods so were combined; resulting in five synthesised trials with 815 stroke participants. Meta-analyses of data from the final assessment in each study and three overlapping time-points showed comparable improvements in walking speed over ten metres (p=0.04-0.95), functional exercise capacity (p=0.10-0.31), timed up-and-go (p=0.812 and p=0.539) and perceived mobility (p=0.80) for both interventions. Conclusion: Data suggest that, in contrast to assumptions that predict FES superiority, AFOs have equally positive combined-orthotic effects as FES on key walking measures for foot-drop caused by stroke. However, further long-term, high-quality RCTs are required. These should focus on measuring the mechanisms-of-action; whether there is translation of improvements in impairment to function, plus detailed reporting of the devices used across diagnoses. Only then can robust clinical recommendations be made

Functional electrical stimulation and ankle foot orthoses provide equivalent therapeutic effects on foot drop: A meta-analysis providing direction for future research

Objective: To compare the randomized controlled trial evidence for therapeutic effects on walking of functional electrical stimulation and ankle foot orthoses for foot drop caused by central nervous system conditions. Data sources: MEDLINE, CINAHL, Cochrane Central Register of Controlled Trials, REHABDATA, PEDro, NIHR Centre for Reviews and Dissemination, Scopus and clinicaltrials.gov. Study selection: One reviewer screened titles/abstracts. Two independent reviewers then screened the full articles. Data extraction: One reviewer extracted data, another screened for accuracy. Risk of bias was assessed by 2 independent reviewers using the Cochrane Risk of Bias Tool. Data synthesis: Eight papers were eligible; 7 involving participants with stroke and 1 involving participants with cerebral palsy. Two papes reporting different measures from the same trial were grouped, resulting in 7 synthesized randomized controlled trials (n= 464). Meta-analysis of walking speed at final assessment (p = 0.46), for stroke participants (p = 0.54) and after 4–6 weeks’ use (p = 0.49) showed equal improvement for both devices. Conclusion: Functional electrical stimulation and ankle foot orthoses have an equally positive therapeutic effect on walking speed in non-progressive central nervous system diagnoses. The current randomized controlled trial evidence base does not show whether this improvement translates into the user’s own environment or reveal the mechanisms that achieve that change. Future studies should focus on measuring activity, muscle activity and gait kinematics. They should also report specific device details, capture sustained therapeutic effects and involve a variety of central nervous system diagnoses

Healthy aims: developing new medical implants and diagnostic equipment

Healthy Aims is a €23-million, four-year project, funded under the EU’s Information Society Technology Sixth Framework program to develop intelligent medical implants and diagnostic systems (www.healthyaims.org). The project has 25 partners from 10 countries, including commercial, clinical, and research groups. This consortium represents a combination of disciplines to design and fabricate new medical devices and components as well as to test them in laboratories and subsequent clinical trials. The project focuses on medical implants for nerve stimulation and diagnostic equipment based on straingauge technology

Skill assessment in upper limb myoelectric prosthesis users: Validation of a clinically feasible method for characterising upper limb temporal and amplitude variability during the performance of functional tasks

Upper limb myoelectric prostheses remain challenging to use and are often abandoned. A proficient user must be able to plan/execute arm movements while activating the residual muscle(s), accounting for delays and unpredictability in prosthesis response. There is no validated, low cost measure of skill in performing such actions. Trial-trial variability of joint angle trajectories measured during functional task performance, linearly normalised by time, shows promise. However, linear normalisation of time introduces errors, and expensive camera systems are required for joint angle measurements. This study investigated whether trial-trial variability, assessed using dynamic time warping (DTW)of limb segment acceleration measured during functional task performance, is a valid measure of user skill. Temporal and amplitude variability of forearm accelerations were determined in 1) seven myoelectric prosthesis users and six anatomically-intact controls and 2) seven anatomically-intact subjects learning to use a prosthesis simulator over repeated sessions. 1: temporal variability showed clear group differences (p<0.05). 2: temporal variability considerably increased on first use of a prosthesis simulator, then declined with training (both p<0.05). Amplitude variability showed less obvious differences. Analysing forearm accelerations using DTW appears to be a valid low-cost method for quantifying movement quality of upper limb prosthesis use during goal-oriented task performance

Repair strategies for assistive technology in low resource settings

PURPOSE: To investigate the practices of repair that exist for users of mobility assistive products in low resource settings, as well as the psychosocial impact that the repair, or non-repair, of these devices has on users' lives. MATERIALS AND METHODS: This article collates data on repair practices and the responses from participants on the topic of repair from studies conducted by the authors across four different low resource settings in Kenya, Uganda, Sierra Leone, and Indonesia. This data was then analyzed to identify the common themes found across geographies. RESULTS: Three major models of repair practice emerged from the data: "Individual or Informal Repair in the Community"; "Local Initiatives"; and "Specialist AT Workshop Repair". Additionally, the wider impact on the participants' lives of "Problems & Concerns with Repair"; "Experiences of Breakages & Frequencies of Repair" and the "Impact of Broken Devices" are explored. CONCLUSIONS: The results of this analysis demonstrate the paramount importance of community-based repair of devices, and how despite this importance, repair is often overlooked in the planning and design of assistive products and services. There is a need to further incorporate and support these informal contributions as part of the formal provision systems of assistive device.IMPLICATIONS FOR REHABILITATIONA lack of available specialist repair services in low resource settings hinders the potential impact of assistive technology provision systems.Community-based repair is the major route by which assistive devices are repaired in low resource settings.Appropriate community-based repair strategies should be incorporated into and supported by the formal assistive technology provision models in order to optimise outcomes.A lack of data on outcomes across the lifecycle of assistive products hinders progress on improving focus on follow-up services - in particular repair & maintenance.By supporting community-based repair, repairs that are inappropriate for that approach could be better directed to specialist repair services

The design, development and evaluation of an array-based FES system with automated setup for the correction of drop foot

Functional electrical stimulation has been shown to be a safe and effective means of correcting drop foot of central neurological origin. However, despite recent technological advances, the set-up of surface stimulators remains a challenge for many users with drop foot. The automation of the setup process through the use of electrode arrays has been proposed as a way to address this problem. This paper describes a series of research and clinical studies which have led to the first demonstration of unsupervised automated setup of an electrode-array based drop foot stimulator. Finally, future research plans are discussed

Evaluation of a novel biomechanics-informed walking frame, developed through a Knowledge Transfer Partnership between biomechanists and design engineers

Background: Walking aids such as walking frames offer support during walking, yet paradoxically, people who self-report using them remain more likely to fall than people who do not. Lifting of walking frames when crossing door thresholds or when turning has shown to reduce stability, and certain design features drive the need to lift (e.g. small, non-swivelling wheels at the front). To overcome shortfalls in design and provide better stability, biomechanists and industrial engineers engaged in a Knowledge Transfer Partnership to develop a novel walking frame that reduces the need for lifting during everyday tasks. This paper presents the results for the final prototype regarding stability, safety and other aspects of usability. Methods: Four studies were conducted that explored the prototype in relation to the current standard frame: a detailed gait lab study of 9 healthy older adults performing repeated trials for a range of everyday tasks provided mechanical measures of stability, a real-world study that involved 9 users of walking frames provided measures of body weight transfer and lifting events, two interview studies (5 healthcare professionals and 7 users of walking frames) elicited stakeholder perceptions regarding stability, safety and usability. Results: Analysis of healthy older adults using a standard walking frame and the prototype frame demonstrated that the prototype increases stability during performance of complex everyday tasks (p < 0.05). Similarly, gait assessments of walking frame users in their home environment showed that the prototype facilitated safer usage patterns and provided greater and more continuous body weight support. Interviews with healthcare professionals and users showed that the prototype was perceived to be safe and effective and hence more usable. Conclusions: The outcomes of the separate studies all support the same conclusion: the prototype is an improvement on the status quo, the typical front-wheeled Zimmer frame for indoor use which has not changed in design for decades. The significance of this work lies in the success of the Knowledge Transfer Partnership and in biomechanics-informed design leading to improvements, which in future may be applied to other walking aids, to benefit walking aid users by promoting safer, more stable use of their aid

Prosthetics services in Uganda : a series of studies to inform the design of a low cost, but fit-for-purpose, body-powered prosthesis

The majority of people with upper limb absence (PWULA) live in lower, or middle-income countries (LMICs). However, efforts to develop improved prostheses have largely focused on electrically powered devices, sustainable deployment of which, in LMICs, is difficult. In the ‘Fit-for-purpose, affordable body-powered prostheses’ project, teams from the UK, Uganda and Jordan are developing mechanically-operated prostheses, optimised for LMICs, and establishing local methods for fabrication, fitting and evaluation. Here we first report on preliminary studies aimed at grounding the project in the reality of current prosthetics services and the experiences of people with limb absence in Uganda. Finally, we outline our ongoing work in the context of our findings. In our first two studies we reviewed current prosthetics and associated repair services. An issue which came up repeatedly was the difficulty faced by orthopaedic technologists in accessing componentry/materials. All specialised prosthetics components and materials are imported, often at a high cost. Purchasing does not appear to be well coordinated between centres, meaning potential economies of scale are not being fully exploited. Although there is supposed to be government funding for prosthetics, in practice budgets are often inadequate and a reliance on donations is common. The resource limitations mean Orthopaedic Technologists often resort to ad-hoc solutions; unsurprisingly perhaps, failures in prostheses were reported. In particular, lamination-based socket manufacture is very difficult, given the complexity (and cost) of the processes involved. Repair services are also limited, in part also due to problems accessing materials/components. Despite (or in part, as a result of) these challenges, the orthopaedic technologists are generally an extremely resourceful and multi-skilled group and there is genuine enthusiasm to see services improve. Further, there is a growth in interest and capabilities in the area of medical device innovation. In the third of our studies, we interviewed 17 PWULA and present preliminary results from the analysis of a subset of five participants. Firstly, we found that only 2 of the participants reported experience with using an upper limb prosthesis, again supporting the picture which emerged from the other studies. The findings illustrate the emergence of four key themes: a) attitude towards disability; b) barriers to prosthesis use; c) coping without a prosthesis; and d) communication with other PWULA. Although attitudes to those with limb loss varied, participants reported impacts in terms of social isolation and a mixed experience of emotions that appeared predominantly negative; barriers to prosthesis use were broader than just cost and functionality, and included a lack of training and psychological support; given that it is difficult to access an upper limb prosthesis, PWULA have found ways to perform daily life activities without relying on one; finally, most PWULA find the suggestion of communicating with other people with the same experience appealing. In our project we are addressing some of the issues found in the preliminary studies. To make socket manufacture less dependent on access to imported materials and specialised equipment, we are investigating the development of lattice-style, adjustable sockets, made from locally available materials. We are also investigating alternatives to the traditional harness-controlled, body-powered prosthetic hands. Given that clinicians have no objective means of evaluating the value of the prosthesis to their clients, we are testing the use of low-cost digital monitoring tools. We are also exploring the potential value of using mobile-phones to reduce the isolation of PWULA. Finally, we are exploring how these innovations may be translated into the Ugandan health setting

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 12 drop of central neurological origin. Current surface-based devices typically consist of a single channel stimulator, 13 a sensor for determining gait phase and a cuff, within which is housed the anode and cathode. The cuff-mounted 14 electrode design reduces the likelihood of large errors in electrode placement, but the user is still fully responsible 15 for selecting the correct stimulation level each time the system is donned. Researchers have investigated different 16 approaches to automating aspects of setup and/or use, including recent promising work based on iterative learning 17 techniques. This paper reports on the design and clinical evaluation of an electrode array-based FES system for 18 the correction of drop foot, ShefStim. The paper reviews the design process from proof of concept lab-based study, 19 through modelling of the array geometry and interface layer to array search algorithm development. Finally, the 20 paper summarises two clinical studies involving patients with drop foot. The results suggest that the ShefStim 21 system with automated setup produces results which are comparable with clinician setup of conventional systems. 22 Further, the final study demonstrated that patients can use the system without clinical supervision. When used 23 unsupervised, setup time was 14 minutes (9 minutes for automated search plus 5 minutes for donning the 24 equipment), although this figure could be reduced significantly with relatively minor changes to the design

Movement variability in stroke patients and controls performing two upper limb functional tasks: a new assessment methodology

Background: In the evaluation of upper limb impairment post stroke there remains a gap between detailed kinematic analyses with expensive motion capturing systems and common clinical assessment tests. In particular, although many clinical tests evaluate the performance of functional tasks, metrics to characterise upper limb kinematics are generally not applicable to such tasks and very limited in scope. This paper reports on a novel, user-friendly methodology that allows for the assessment of both signal magnitude and timing variability in upper limb movement trajectories during functional task performance. In order to demonstrate the technique, we report on a study in which the variability in timing and signal magnitude of data collected during the performance of two functional tasks is compared between a group of subjects with stroke and a group of individually matched control subjects. Methods: We employ dynamic time warping for curve registration to quantify two aspects of movement variability: 1) variability of the timing of the accelerometer signals' characteristics and 2) variability of the signals' magnitude. Six stroke patients and six matched controls performed several trials of a unilateral ('drinking') and a bilateral ('moving a plate') functional task on two different days, approximately 1 month apart. Group differences for the two variability metrics were investigated on both days. Results: For 'drinking from a glass' significant group differences were obtained on both days for the timing variability of the acceleration signals' characteristics (p = 0.002 and p = 0.008 for test and retest, respectively); all stroke patients showed increased signal timing variability as compared to their corresponding control subject. 'Moving a plate' provided less distinct group differences. Conclusion: This initial application establishes that movement variability metrics, as determined by our methodology, appear different in stroke patients as compared to matched controls during unilateral task performance ('drinking'). Use of a user-friendly, inexpensive accelerometer makes this methodology feasible for routine clinical evaluations. We are encouraged to perform larger studies to further investigate the metrics' usefulness when quantifying levels of impairment