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Trial registered on ANZCTR


Registration number
ACTRN12617000543381
Ethics application status
Approved
Date submitted
11/04/2017
Date registered
18/04/2017
Date last updated
29/03/2018
Type of registration
Prospectively registered

Titles & IDs
Public title
Do different shoe insole surfaces affect balance and walking in adults with diabetes and foot nerve damage?
Scientific title
Do different shoe insole surfaces affect balance and walking in adults with diabetic peripheral neuropathy? A randomised controlled trial
Secondary ID [1] 291610 0
Nil known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Diabetic Peripheral Neuropathy 302723 0
Type 2 Diabetes 302724 0
Balance and Walking Impairment 302734 0
Falls Risk 302735 0
Condition category
Condition code
Metabolic and Endocrine 302245 302245 0 0
Diabetes
Physical Medicine / Rehabilitation 302246 302246 0 0
Other physical medicine / rehabilitation
Neurological 302350 302350 0 0
Other neurological disorders

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Textured insoles constructed from 3.2mm poron (Poron 4000, Algeos Ltd., VIC, Australia), covered with 100% PVC material which has raised pyramidal nodules (Techno PVC covering, Black Tech, Algeos Ltd., VIC, Australia). To reduce the risk of ulceration, the textured zone will extend from the heel to just posterior to the metatarsal heads (foot region most prone to ulcers). Participants will be instructed to wear the textured insoles, in their own shoes, as much as possible over the 4-week intervention period. Participants will be followed for 4-weeks with insole-wear diaries to determine the number of hours insoles are worn. All participants will receive emergency contact details for a local podiatrist, who will provide advice and podiatry care for participants, as required.
Intervention code [1] 297684 0
Treatment: Devices
Intervention code [2] 297685 0
Prevention
Intervention code [3] 297686 0
Rehabilitation
Comparator / control treatment
Smooth, control insoles will be constructed from 3.2mm poron (no PVC top cover) (Poron 4000, Algeos Ltd., VIC, Australia), and thus have a flat surface with no indentations. Participants will be instructed to wear the smooth control insoles, in their own shoes, as much as possible over the 4-week intervention period. Participants will be followed for 4-weeks with insole-wear diaries to determine the number of hours insoles are worn. All participants will receive emergency contact details for a local podiatrist, who will provide advice and podiatry care for participants, as required.
Control group
Placebo

Outcomes
Primary outcome [1] 301657 0
Centre of Pressure Movement during Standing Balance:

Centre of pressure path velocity, range and standard deviation of centre of pressure movement in anterior-posterior and mediolateral directions during unperturbed, double-limb standing, performed on a firm and foam surface, with eyes open and eyes closed. Measured using a force platform (AMTI).
Timepoint [1] 301657 0
Baseline Assessment (Upon entry into study)
Post-Intervention Assessment (4-weeks after the commencement of insole use)
Primary outcome [2] 301658 0
Spatiotemporal Gait Parameters:

Base of support, stride length, double-limb support time, gait velocity during walking over a level-ground surface. Measured using an electronic walkway system (GAITRite).
Timepoint [2] 301658 0
Baseline Assessment (Upon entry into study)
Post-Intervention Assessment (4-weeks after the commencement of insole use)
Primary outcome [3] 301659 0
Foot Sensation and Proprioception:

Light-touch sensation, vibration sense, ankle joint position sense. Measured using monofilaments, neurothesiometer, and 2-dimensional webcam kinematic software analysis application.
Timepoint [3] 301659 0
Baseline Assessment (Upon entry into study)
Post-Intervention Assessment (4-weeks after the commencement of insole use)
Secondary outcome [1] 333472 0
Physical Activity:

Duration/bouts of physical activity (min/day), as a measure of habitual weekly activity levels. Measured using a wireless activity monitor (activPAL, Glasgow, Scotland), worn for 7 consecutive days.
Timepoint [1] 333472 0
Baseline Assessment (Upon entry into study)
Post-Intervention Assessment (4-weeks after the commencement of insole use)
Secondary outcome [2] 333473 0
Self-Reported Foot Health:

Foot Health Status Questionnaire (a measure of self-perceived foot-health specific, quality of life before and after an intervention).
Timepoint [2] 333473 0
Baseline Assessment (Upon entry into study)
Post-Intervention Assessment (4-weeks after the commencement of insole use)
Secondary outcome [3] 333813 0
Number of Falls:

Number of self-reported falls in the previous 12 months and over the intervention period (measured using a falls diary).
Timepoint [3] 333813 0
Baseline Assessment (Upon entry into study)
Post-Intervention Assessment (4-weeks after the commencement of insole use)
Secondary outcome [4] 333814 0
Fear of Falling:

Falls Efficacy Scale-International (a questionnaire that measures fear of falling).
Timepoint [4] 333814 0
Baseline Assessment (Upon entry into study)
Post-Intervention Assessment (4-weeks after the commencement of insole use)

Eligibility
Key inclusion criteria
Men and women aged 18 years or above; with a clinical diagnosis of peripheral neuropathy secondary to Type 2 diabetes; ambulant over 20 metres with/without the use of an assistive device (cane/crutch), willing to wear shoe insoles for 4 weeks and; have adequate English communication skills.
Minimum age
18 Years
Maximum age
No limit
Gender
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
Current foot ulceration or lower limb injury
Major lower limb amputation
Currently using over-the-counter or custom-made foot orthoses/insoles
Charcot Arthropathy
Neurological disease
Cardiorespiratory conditions that limit ambulation
Cognitive impairment

Study design
Purpose of the study
Treatment
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Participants will be randomised to either the textured insole or smooth (control) insole group (in a 1:1 ratio). The concealed randomisation schedule will be managed by an independent offsite investigator, and revealed to a clinician who is only responsible for issuing the insoles. All other Chief Investigators and Research Assistants will be blinded to group allocation. Participants will be instructed not to divulge their allocation. Following Baseline Assessment, the Principal Investigator and Research Assistant will leave the gait laboratory to ensure blinding to the insole condition. The clinician will then fit the participant with their allocated insole, and provide advice regarding: frequency of wear; completion of insole wear diaries and; contact details for a local podiatrist.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
The sequence will be generated using permuted block randomisation, created by computer software (computerised sequence generation).
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?


The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint(s)
Efficacy
Statistical methods / analysis
Sample size was calculated for our primary outcome measure of centre of pressure velocity, using data from Kalron et al. (2015), who reported between-condition differences (shoes only and shoes + textured insole) that equated to an effect size of 0.72. Based on these data, 32 participants per group will provide sufficient power to detect differences in balance of a similar magnitude (a=0.05, beta=0.20). We will allow for a 10% attrition rate over the 4 week intervention period, and recruit 35 participants per group (control group and intervention group).

All analyses will be conducted in a blinded manner, on an intention-to-treat basis. Statistical analyses will be performed using SPSS version 24 (SPSS Inc, Chicago, IL 60606, USA). Data will be examined for normality and homogeneity of variance. To establish any differences between the intervention and control groups in balance, gait, physical activity, foot sensation and proprioception measures, self-reported foot heath and falls over the intervention period, a repeated measures mixed models approach will be undertaken using data at baseline and 4-weeks. Non-parametric tests will be used where data is not normally distributed or violates the assumption of sphericity. Participant characteristics (e.g. age, gender) will be included as covariates. Multiple regression modelling will be used to determine any relationships between foot sensation and proprioception, balance and gait.

Recruitment
Recruitment status
Recruiting
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
QLD

Funding & Sponsors
Funding source category [1] 296097 0
Charities/Societies/Foundations
Name [1] 296097 0
Diabetes Australia
Address [1] 296097 0
Diabetes Australia National Office
Level 1, 101 Northbourne Avenue
Turner
ACT 2612
Country [1] 296097 0
Australia
Primary sponsor type
Individual
Name
Dr Anna Hatton
Address
School of Health and Rehabilitation Sciences,
Therapies Building (84A),
The University of Queensland,
St Lucia,
QLD 4072
Country
Australia
Secondary sponsor category [1] 294992 0
Individual
Name [1] 294992 0
Professor Graham Kerr
Address [1] 294992 0
Institute of Health & Biomedical Innovation,
Queensland University of Technology
Kelvin Grove
QLD 4059
Country [1] 294992 0
Australia
Secondary sponsor category [2] 294995 0
Individual
Name [2] 294995 0
Professor Joshua Burns
Address [2] 294995 0
Sydney Children's Hospitals Network
The University of Sydney
Locked Bag 4001
Westmead
NSW 2145
Country [2] 294995 0
Australia
Secondary sponsor category [3] 294996 0
Individual
Name [3] 294996 0
Professor Keith Rome
Address [3] 294996 0
Auckland University of Technology (AUT)
90 Akoranga Drive
Northcote
Auckland 0627
Country [3] 294996 0
New Zealand
Secondary sponsor category [4] 294997 0
Individual
Name [4] 294997 0
Dr Joanne Paton
Address [4] 294997 0
Faculty of Health and Human Sciences
Peninsula Allied Health Centre, Room FF21
Derriford Road
Plymouth
Devon PL6 8BH
Country [4] 294997 0
United Kingdom

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 297354 0
University of Queensland Human Research Ethics Committee
Ethics committee address [1] 297354 0
UQ Research and Innovation
The University of Queensland
Cumbrae-Stewart Building (#72)
Brisbane
QLD 4072
Ethics committee country [1] 297354 0
Australia
Date submitted for ethics approval [1] 297354 0
27/01/2017
Approval date [1] 297354 0
10/04/2017
Ethics approval number [1] 297354 0
2017000098

Summary
Brief summary
Many people with diabetes experience problems with their balance and walking, which can make day to day activities difficult and increase the chance of sustaining a fall. Nerve damage (a common complication of diabetes) can severely disrupt the quality of the signals transmitted from the feet to the brain, which provide vital cues about the ground we stand on and the relative position of our body above, to help people remain upright. Novel footwear devices are emerging as an attractive treatment option to help alleviate balance and walking problems and reduce the risk of falling in adults with diabetic peripheral neuropathy (nerve damage). Textured shoe insoles (comprising raised nodules) are designed to enhance the signals from foot skin receptors, which is important for good balance. This randomized controlled trial will be the first to explore whether use of different shoe insole surfaces (over 4-weeks) can improve balance and walking performance in adults with diabetic peripheral neuropathy. We will also investigate whether any alterations in balance or walking are associated with underlying changes in the amount of remaining feeling in participants’ feet (measures of foot sensation and foot position awareness). Additionally, we will explore whether wearing different shoe insole surfaces lead to improvements in physical activity levels or measures of self-reported foot heath and falls in adults with diabetic peripheral neuropathy. This study will bring new perspective to our understanding of the therapeutic role of footwear interventions, as a means to address deficient postural control in adults with neuropathic changes at the feet. The findings will be used to inform the development of new rehabilitative approaches that will help advance clinical guidelines and policy, and reduce the escalating personal, societal and economic burden of falls in people with diabetes.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 73786 0
Dr Anna Hatton
Address 73786 0
School of Health and Rehabilitation Sciences
Therapies Building (84A)
The University of Queensland
St Lucia, Brisbane
QLD 4072
Country 73786 0
Australia
Phone 73786 0
+61733654590
Fax 73786 0
Email 73786 0
a.hatton1@uq.edu.au
Contact person for public queries
Name 73787 0
Dr Anna Hatton
Address 73787 0
School of Health and Rehabilitation Sciences
Therapies Building (84A)
The University of Queensland
St Lucia, Brisbane
QLD 4072
Country 73787 0
Australia
Phone 73787 0
+61733654590
Fax 73787 0
Email 73787 0
a.hatton1@uq.edu.au
Contact person for scientific queries
Name 73788 0
Dr Anna Hatton
Address 73788 0
School of Health and Rehabilitation Sciences
Therapies Building (84A)
The University of Queensland
St Lucia, Brisbane
QLD 4072
Country 73788 0
Australia
Phone 73788 0
+61733654590
Fax 73788 0
Email 73788 0
a.hatton1@uq.edu.au

No data has been provided for results reporting
Summary results
Not applicable