In-shoe Pressures associated with Footwear Fit Guidelines
Research type
Research Study
Full title
Evaluation of Footwear Fit Guidelines Under Pressure in At-Risk Feet
IRAS ID
273255
Contact name
Rachel Berrington
Contact email
Sponsor organisation
University Hospitals of Leicester NHS Trust
Clinicaltrials.gov Identifier
Duration of Study in the UK
1 years, 0 months, 2 days
Research summary
Research Summary
One in five foot ulcers are caused by the footwear worn by people with diabetes, yet there is a lack of consensus around footwear fit. Recommended toe gaps (the gap between the longest toe and the inside of the shoe) vary depending on the footwear guidance referred to but no research to date has assessed their effectiveness in minimising in-shoe pressures.
We will carry out a pilot study in 60 people with diabetes and loss of sensation in their feet (neuropathy). In this study, we will measure in-shoe pressures whilst participants walk at the same pace to the beat of a metronome. An insole placed inside their shoes will measure in-shoe pressures. They will wear the same (standardised) type of footwear. The study is designed to detect a difference in pressure within this made-to-measure footwear between shoes whose fit conforms to Standard 1 guidance compared with those whose fit conforms to Standard 2 guidance. Differences between Standards 1 and 2 with Standard 3 will be considered secondary analyses. Standards are simplified to three non-overlapping recommended toe gap ranges of 0.5-1.0cm; 1.5-2.0cm and 1.0-1.5cm.
We will also analyse the heat images taken with a thermographic camera before and after walking in standardised footwear whose fit confirms to these standards. Footwear fit will be determined by measuring the dimensions of participants’ feet and that of their footwear and comparing the two.We will also measure footwear fit and associated in-shoe pressure/plantar thermal stress response in participants’ habitual footwear during walking at paced and self-selected speeds.
Lay summary of study results
Background: Footwear fit advice for people with diabetes often varies – especially appropriate ranges for toe gaps within footwear. Toe gaps are the difference between the length inside the shoe available to the foot and the length of the foot itself (the space at the end of the longest toe. The study involved looking at how toe gaps affect pressures inside footwear measured with a special insole and foot temperatures measured with a camera that measures heat. There are three different standards for toe gap, each with a different range: Standard 1 (recommending 0.5-1.0 centimetres of wiggle room – a gap at the end of the longest toe), Standard 2 (1.5-2.0 centimetres) and Standard 3 (1.0-1.5 centimetres). We wanted to know how these recommended toe gaps affect pressure under the foot and forefoot, midfoot and rearfoot temperature.
Recruitment: A total of 36 people with diabetes consented to take part in the study and were screened. 10 were ineligible to take part (for example, they needed walking sticks or crutches which meant pressures might be affected on one side or they had foot swelling that might affect footwear fit and so on). 26 participants were recruited to the study. However, one participant had to leave the study when no longer satisfying the inclusion criteria (absent foot pulses). 25 participants therefore completed both first and second visits comprising the study with no-one dropping out.
There were also numerous other people who wanted to take part, but who didn’t meet the criteria to be able to take part when we spoke to them during telephone or in person assessment during visits to community centres.
Expressions of interest in the study were gathered through proactive recruitment strategies that included engagement with five public libraries, eight community centres, twelve places of worship, four sports centres, four social networks/community online groups, three community groups and one radio station interview based on five substantial study amendments to attempt to increase recruitment.Study data: We got less data (study information) than we were hoping for some outcomes due either to technical difficulties with equipment or given a diverse group of people with diabetes with unexpectedly large foot sizes for example (up to size 13), sensitivity to new footwear or difficulties with required pace. (Pressures inside shoes and foot temperatures within standardised footwear were available for 17 and 19 participants respectively). (In-shoe pressures and temperatures within habitual footwear were available for 17 and 20 participants for paced and self-selected speed walking respectively) We removed steps where participants were speeding up or slowing down from the steps we were measuring and checked variation during steps and differences in pressure between feet as part of our quality assurance. We checked for errors including any measurements outside the anticipated range.
Originality: This remains the first and only study to have investigated how recommended footwear fit (toe gap) affects in-shoe pressures and temperatures in people with diabetes, providing completely new data.Results: Average pressures inside shoes at the right big toe during walking were higher in standardised footwear with long toe gaps (Standard 2: 1.5-2.0 centimetres) as compared with short toe gaps (Standard 1: 0.5-1.0 centimetres). Average pressures within shoes were 142.2 kilopascals of pressure in short toe gap footwear as compared with 236.3 kilopascals of pressure in longer toe gap footwear – a statistically significant difference. Differences in pressures at other foot regions and in foot temperatures were not statistically significant.
REC name
East Midlands - Nottingham 2 Research Ethics Committee
REC reference
22/EM/0210
Date of REC Opinion
18 Oct 2022
REC opinion
Further Information Favourable Opinion