Title: Enhancing Mobility for elderly stroke survivors using 3D printed custom made ankle foot orthotics.
Funder: Economic and Social Research Council

Abstract: The aim of this work is to enhance the quality of life of elderly stroke survivors by improving their mobility which will in turn mitigate the psychological side effects. In 2019, 19% of the UK population was aged 65 or over (House of Commons Library). Their quality of life and general wellbeing is significantly dependent on mobility which is influenced by cognitive, psychosocial, physical, environmental and financial determinants. Stroke is one health condition that affects cognitive, physical and psychological aspect of life with an incidence of 100 000/year within the UK resulting in 1.3 million of stroke survivors in 2018 (Stroke Association). Out of those affected, 59% are elderly patients with a 30% probability of recurrence. Three quarter of the stroke survivors will have leg weakness, reducing their mobility. They face substantial change in their personal, social and work lives. They lose their independence and are affected psychologically which affect their quality of life significantly. Being active is one step towards achieving stroke survivor's independence and lifting their mood while enhancing their general wellbeing. Foot drop is related to the weakness or complete absence of dorsiflexion (bending backwards) of ankles and toes which arises from a stroke. Foot drop is one of the main reasons elderly stroke patients have diminished mobility. It can be managed effectively with a custom-made rigid AFO which has been proven to increase the gait velocity, step length and cadence (number of gait cycle per minute) when used at an early-stage stroke intervention. Currently, most AFOs provided to NHS patients are made of polypropylene and ethyl vinyl acetate (EVA) which have high carbon footprints (3.05 and 2.1 Kg CO2/Kg respectively), which is detrimental to the environment. In the UK people above 55 years old are most concerned about the environment and if provided with environmentally friendly products, will be keener to use it. Furthermore, only 12.7 % of AFOs provided to the NHS patients were classified as custom-made in 2016, although custom-made AFOs have a better fit and are more clinically effective. Most NHS prescribers uses foam boxes and plaster casting for shape capture followed by moulding processes that are labour-intensive. This results in a lead time of 4-12 weeks for a patient to receive a custom made AFO. This adds a minimum of 1 month of reduced mobility and activity to the patients' lives which increases their discomfort and frustration further. Alternative efficient solutions are 3D scanning (3DS), for shape capture, which is less prone to error, with higher accuracy and a quicker process followed by 3DP, for automated manufacture, which produce better fit AFO (minimum adjustment required) and allows personalisation. The latter manufacturing cycle can result in reduction of lead time to less than 5 days (Proven concept). Examples of companies supplying to the NHS are Blatchford, Footlabs (uses 3DS and 3DP) and Lakeland Orthotic. None of them provide sustainable solutions. However, there are companies within and outside the UK that are starting to provide sustainable insoles (not AFOs) such as Firefly (N. Ireland), Insite (USA) and Ortholite (USA). Firefly has started using polyamide 11 (PA11) which is a biobased material (made from castor oil) with a carbon footprint of -2.2 Kg CO2/Kg (3D Printing). PA11 is known to perform in extreme sporting environment and hence is an excellent candidate for custom-made AFOs. A new approach is needed to support the NHS provide elderly stroke survivors with sustainable bespoke AFOs with enhanced clinical efficacy (High accuracy, better fit) with a significantly reduced waiting time.

Lay abstract: There are over 1.2 million stroke survivors in the UK with approximately 60% aged 65 years or over. One of the disabilities that they have, is lower limb weakness, which reduces their mobility significantly. Ankle foot orthotics (AFOs) provided by the NHS help manage the symptom. However, there is a 4 -12 weeks wait before they can receive a custom-made AFO, which is clinically more effective than off-the-shelf AFOs. This is because of the process used, to capture the shape of the ankle-foot (Plaster casting - Labour-intensive) and then to manufacture the AFO (Moulding - Labour-intensive), is time consuming. Furthermore, the material used for the AFOs are plastic-based which destroys the environment. The proposed idea is to recruit elderly stroke patients, assess their needs with respect to mobility and make a priority list of those needs. Then, their ankle-foot section will be 3D scanned which is an automated shape-capture process. This is currently done by <3% of NHS Trusts. The resulting custom designed AFO will then be 3D printed, which is an automated manufacturing process, using a zero-carbon material made from castor oil. The wait time to receive an AFO will be reduced to <5days. The aim of this work is to increase the mobility of elderly stroke patients at the earliest time possible. This will enhance the quality of life of those patients, both physically and mentally. Below is an illustrative summary.

Research activity codes: 7.1 INDIVIDUAL CARE NEEDS
Health categories: STROKE