This study aims to investigate the effects of custom-designed insoles produced using Computer Numerical Control (CNC) and 3D printers on plantar pressure distribution analysis, foot posture, plantar force distribution, foot pain, and satisfaction in patients diagnosed with pes planus.

This randomized controlled trial evaluates the impact of custom-designed insoles, created using Computer Numerical Control (CNC) and 3D printing technologies, on plantar pressure distribution, foot posture, pain, and user satisfaction in individuals with flexible pes planus. The study targets adults aged 18-55, with specific clinical and postural inclusion criteria, and excludes individuals with biomechanical or neurological confounders.

Participants are randomly assigned to one of two intervention groups using a simple randomization method: one receiving CNC-produced insoles and the other 3D-printed insoles. Assessments are conducted before and after 8 weeks of insole use, employing standardized tools such as the Foot Posture Index, subtalar angle measurement, plantar pressure analysis, and satisfaction/function questionnaires. The primary aim is to explore comparative biomechanical and subjective outcomes to inform best practices in orthotic design and application.

Inclusion Criteria:

• Individuals aged between 18 and 55 years
• Diagnosed with flexible pes planus (flat feet)
• No prior use of custom orthotic insoles within the past 6 months
• Able to walk independently without assistive devices
• Voluntarily agree to participate and provide informed consent

Exclusion Criteria:

• History of lower limb or foot surgery
• Presence of neurological, rheumatologic, or musculoskeletal disorders affecting gait
• Presence of severe foot deformities (e.g., rigid pes planus, cavus foot)
• Use of medications that affect muscle or joint function
• Pregnancy