What are the key components of a diabetic shoe prescription?

Diabetic Shoe Prescription Components

A diabetic shoe prescription must be risk-stratified: patients with healed plantar ulcers require therapeutic footwear with documented ≥30% plantar pressure reduction or peak pressure <200 kPa, while those with foot deformities need extra-depth or custom-made shoes with custom insoles, and low-risk patients need properly fitting footwear that accommodates foot shape. 1

Risk-Based Prescription Algorithm

IWGDF Risk 1-3 WITHOUT Foot Deformity or Ulcer History

• Prescribe properly fitting footwear with adequate length, width, and depth that accommodates the foot shape 1
• Educate patient to check inside shoes for foreign objects before wearing 1
• Instruct patient never to walk barefoot, in socks only, or in thin-soled slippers indoors or outdoors 1

IWGDF Risk 2-3 WITH Foot Deformity or Pre-ulcerative Lesions

• Consider prescribing extra-depth shoes (minimum 5mm additional depth compared to standard footwear) to accommodate claw/hammer toes and thick insoles 1
• Add custom-made insoles molded under semi-weight-bearing conditions for optimal pressure redistribution, particularly at metatarsal heads 2, 3
• Include toe orthoses for digital deformities with pre-ulcerative signs 1
• Custom-made footwear may be necessary depending on deformity severity 1

IWGDF Risk 3 WITH Healed Plantar Foot Ulcer

This is the most critical prescription requiring objective pressure measurement: 1

• Mandatory therapeutic footwear with demonstrated plantar pressure relief defined as either:
  • ≥30% reduction in peak in-shoe pressure at high-risk locations compared to standard therapeutic footwear, OR
  • In-shoe peak pressure <200 kPa during walking 1
• Measure with validated, reliable, calibrated in-shoe pressure system with 2 cm² sensors 1
• Rocker-bottom sole modification reduces forefoot peak pressures by approximately 30% at medial/central forefoot and toes 4, 2
• Custom-made insoles with metatarsal additions and maximum foot contact area 2, 3
• Emphasize continuous wear indoors and outdoors as adherence is critical for effectiveness 1

Essential Prescription Components

Footwear Specifications

• Extra-depth construction for accommodating insoles and deformities 1
• Multiple width fittings available 1
• Modified soles (rocker-bottom design preferred for plantar ulcer history) 4, 2
• Smooth internal linings without rough edges or uneven seams 1, 5
• Appropriate fastenings that allow adjustment 1

Insole Requirements

• Custom-molded using foot impressions or molds under semi-weight-bearing conditions for optimal pressure distribution 1, 3
• Contoured design significantly superior to flat insoles for peak pressure reduction 3
• Semi-rigid orthotic devices may be needed for specific biomechanical correction 1

Hosiery Recommendations

• Natural material/thread composition (cotton, wool) 1
• Seamless construction to prevent irritation 1
• Light color preferred so blood stains from pre-ulcerative lesions become visible 1
• Change at least once daily 6

Critical Patient Education Points

Daily Footwear Inspection Protocol

• Inspect inside of shoes daily for foreign objects, rough areas, or worn linings before donning 1, 5
• Palpate shoe interior to detect potential irritants 6, 5
• Never wear shoes without socks to prevent moisture buildup 6

Prohibited Footwear

• No barefoot walking indoors or outdoors 1, 5
• No walking in socks only 1
• No thin-soled slippers or flip-flops 1
• Avoid tight shoes or knee-high socks 6

Common Prescription Pitfalls

Inadequate pressure measurement: Prescribing "therapeutic footwear" for healed plantar ulcers without objective pressure verification fails to meet the standard of care 1. Where pressure measurement technology is unavailable, use state-of-the-art scientific knowledge on effective offloading designs (rocker soles, custom insoles with metatarsal bars) 1, 2.

Ignoring adherence factors: Even optimal footwear fails if not worn consistently 1. Address cultural considerations, comfort, and aesthetics during prescription 1.

One-size-fits-all approach: The significant inter-patient variability in offloading response requires individualized pressure assessment rather than standardized prescriptions 7.

Neglecting follow-up: Footwear effectiveness must be re-evaluated, particularly since 40% of ulcers recur within one year despite appropriate footwear 5.

Documentation Requirements

The prescription should specify:

• IWGDF risk category (1,2, or 3) 1
• Specific foot deformities present 1
• Ulcer history and location if applicable 1
• Required pressure reduction targets for healed ulcers 1
• Custom modifications needed (rocker sole angle, insole specifications) 4, 2
• Follow-up schedule: every 1-3 months for ulcer history 5