3D Printed vs Ready-to-Wear Insoles for Diabetic Neuropathy

Comparative Effect of 3D Printed Customized Insoles and Ready to Wear Insoles on Plantar Pressure Changes in Patients With Diabetic Neuropathy

Diabetic neuropathy is a condition caused by chronic high blood glucose levels that damage nerves over time, frequently causing abnormal plantar pressure and increasing the risk of foot ulcers and impaired mobility. Insoles are widely used to redistribute pressure and improve comfort. This study compares the effect of 3D printed customized insoles versus ready-to-wear insoles on plantar pressure changes in patients with diabetic neuropathy. The study is a randomized controlled trial with 22 participants randomly allocated to two groups: one receiving 3D printed customized insoles and the other receiving ready-to-wear insoles. Plantar pressure is measured using piezoresistive sensors and an Arduino Nano Unit. Secondary outcomes include foot health status (FSHQ questionnaire), satisfaction with assistive technology (QUEST 2.0), and neuropathy severity (NSS and NDS questionnaires). Assessments occur at baseline, 4 weeks, and 8 weeks.

This is a single-blind, parallel-group randomized controlled trial conducted at DHQ-1 and DHQ-2 hospitals in Okara, Pakistan. Participants are adults aged 35-65 years with diagnosed diabetic neuropathy who can walk independently without aids. Exclusion criteria include foot ulcers, external wounds, recent surgery, major limb amputation, foot drop, peripheral vascular disease, neuromuscular diseases, and Charcot arthropathy. A consecutive sampling technique is used to recruit 22 participants. Randomization is performed using a computer-generated sequence. Participants are blinded to their group allocation. Group A receives 3D printed customized insoles tailored to individual foot morphology using 3D scanning and printing technology. These insoles provide arch support and gait alignment. Group B receives ready-to-wear insoles providing general cushioning and basic support. Both groups follow an 8-week intervention protocol: participants wear insoles for a minimum of 6 hours per day, 5 days per week, and perform level walking on a 28-meter pathway at self-selected speed. The protocol is divided into phases: weeks 1-2 for acclimatization and footwear assessment using Semmes-Weinstein 10g monofilament; weeks 3-4 for pressure adaptation and skin monitoring; weeks 5-6 for enhanced foot function and balance improvement; weeks 7-8 for final assessment. Primary outcome: plantar pressure measured via piezoresistive sensors and Arduino Nano Unit. Secondary outcomes: Foot Health Status Questionnaire (FSHQ), Quebec User Evaluation of Satisfaction with Assistive Technology (QUEST 2.0), Neuropathy Symptom Score (NSS), and Neuropathy Deficit Score (NDS). Data are collected at baseline, week 4, and week 8. Statistical analysis uses SPSS version 22.

Inclusion Criteria:

• Age 35 to 65 years
• Diagnosed with diabetes mellitus
• Clinical diagnosis of diabetic peripheral neuropathy
• Ability to walk independently without walking aids
• Normal cognitive function
• Corrected or uncorrected vision sufficient for safe ambulation
• Willingness to provide written informed consent

Exclusion Criteria:

• Presence of active foot ulcer
• External wound on lower extremity
• History of lower limb surgery within past 6 months
• Major lower limb amputation
• Foot drop
• Peripheral vascular disease
• Neuromuscular diseases (e.g., stroke, Parkinson's disease, multiple sclerosis)
• Charcot arthropathy
• Inability to comply with study protocol