Rationale: Of all individuals with diabetes, 19-34% develop a foot ulcer in their lifetime, and nearly 25% of these ulcers result in amputation. Ulcer prevention is often addressed by prescribing orthopedic shoes (OS). However, the effectiveness of OS is highly dependent on the individual shoe technician's skill and experience, and OS is frequently perceived as unattractive by users.

To overcome these limitations, the LEEF-shoe was developed. It eliminates the need for a fully individualized shoe technician approach by using a standardized protocol to determine the rocker settings. This may provide comparable plantar pressure relief, while potentially improving patient acceptance due to its more appealing design and simplified prescription process.

Objective: The primary objective is to determine whether the LEEF-shoe differs from standard-OS in terms of plantar pressure distribution. Secondary objectives are evaluation of wearing time and user acceptance of both footwear types.

Study design: This study is a randomized cross-over trial. Participants will complete pre- and post-tests for plantar pressure distribution, wearing time will be measured, and focus group sessions will assess user experience and acceptance.

Study population: A total of 30 adults (≥18 years old) with diabetes mellitus and peripheral neuropathy, at increased risk for foot ulceration, will be included.

Intervention:

All participants will receive two pairs of OS, a standard-OS and an additional OS (e.g., the LEEF-shoe), both provided through usual care channels. At handover, plantar pressure measurements will be performed. Participants will then wear each shoe model for four weeks, one after the other, with wearing time continuously monitored. Following the 8-week period, participants return for a standard control appointment with the OS-technician, during which post-test pressure measurements are taken. Subsequently, participants are allowed to wear either shoe based on personal preference for an additional four weeks, during which wearing time continues to be recorded. The study concludes with focus group sessions to explore experiences and acceptance.

Main study parameters/endpoints:

The primary outcome of the study is peak plantar pressure. It will be compared between the standard-OS and LEEF-shoe during the randomization visit. The secondary outcomes are peak plantar pressures in 7 foot regions, wearing time of the OS and user experience and acceptance, assessed through semi-structured focus groups.

Nature and extent of the burden and risks associated with participation, benefit and group relatedness: Participants will be screened for eligibility during their regular consultation with the prescribing physician and OS-technician. After inclusion, participants will follow standard care procedures, which include an initial shoe fitting, a midway fitting, the handover of both shoes, and two follow-up appointments. To minimize any potential risk associated with wearing the LEEF-shoe at home following the handover, it is required that the LEEF-shoe is at least equivalent to, or better than, the standard-OS in terms of function and safety. Since the LEEF-shoe is produced within the existing framework and standards of OS manufacturing, it is considered a variant of standard-OS and thus falls within the boundaries of standard care.

Inclusion Criteria:

• Aged 18 years or older
• Diabetes mellitus type 1 or 2
• IWGDF Risk 2 - 3
• Prescribed with fully custom-made orthopedic footwear (OS type A)
• Ability to provide informed consent

Exclusion Criteria:

• Severe foot deformities
• Active Charcot's neuroarthropathy
• Foot ulcer or open amputation site
• Severe illness, based on clinical judgment by the physician
• Not able to walk at least 10 meters uninterrupted

Data will be stored in a registry or be made available upon reasonable request.