The Effect of Insoles in Plantar Fasciitis (Insoles)

August 26, 2026 updated by: Hande YAZICI, Medipol University

Effects of Custom Made EVA and 3D-Printed TPU Insoles on Gastrocnemius Muscle Activation and Static Pedobarographic Parameters in Plantar Fasciitis

This randomized active-comparator clinical trial compared changes over 12 weeks between customized computer numerical control (CNC)-milled ethylene-vinyl acetate (EVA) and fused deposition modelling (FDM) 3D-printed thermoplastic polyurethane (TPU) insoles with plantar fasciitis. The primary outcome was bilateral gastrocnemius medialis and lateralis muscle activation recorded using surface electromyography during a standardized 10-meter walking task. Secondary outcomes included static plantar loading, pain, foot-related function, and user satisfaction. Because both groups received custom-made insoles as active interventions, the trial was designed to compare the two orthosis types rather than to determine the absolute efficacy of insoles.

Study Overview

Detailed Description

Plantar fasciitis is a common cause of plantar heel pain that may limit weight-bearing activities and reduce foot-related function. Custom-made insoles are frequently used in conservative management; however, direct evidence comparing orthoses produced using different materials and manufacturing methods remains limited.

This study was designed as an exploratory, parallel-group, randomized active-comparator trial. Forty-one participants with plantar fasciitis were randomly allocated to receive either a custom-made ethylene-vinyl acetate (EVA) insole manufactured using computer numerical control (CNC) milling or a custom-made thermoplastic polyurethane (TPU) insole manufactured using fused deposition modelling (FDM) three-dimensional printing. Participants were assessed at baseline and after 12 weeks of orthosis use.

The primary objective was to compare the effects of the two orthosis types on static plantar loading characteristics and gastrocnemius muscle activation. Static plantar loading was evaluated using pedobarography. Surface electromyography was used to record the activity of the bilateral gastrocnemius medialis and lateralis muscles during a standardized 10-metre walking task. Electromyographic measurements were normalized to maximum voluntary contraction recordings obtained during standardized plantar-flexion and dorsiflexion tasks. The 10-metre walk was used as the standardized task during which electromyographic data were collected and was not evaluated as a walking-performance outcome.

Secondary assessments included pain intensity, pressure pain threshold, foot-related function and participant satisfaction with the assigned orthosis. Pain intensity was evaluated under different symptom-provoking conditions, including first-step morning pain, pain during palpation and pain associated with prolonged standing.

Because both groups received custom-made insole as active interventions and the study did not include a sham, usual-care or untreated control group, the trial was designed to compare the two orthosis types rather than to determine the absolute efficacy of insoles. Accordingly, the findings were intended to describe between-group differences between CNC-milled EVA and FDM 3D-printed TPU insoles over the 12-week follow-up period.

Study Type

Interventional

Enrollment (Actual)

41

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • Istanbul
      • Beykoz, Istanbul, Turkey (Türkiye), 34815
        • Istanbul Medipol University, Prosthetics and Orthotics Center (POMER)

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Aged between 18 and 65 years
  • Clinical diagnosis of plantar fasciitis by a specialist physician
  • Clinical indication or prescription for custom-made foot orthoses
  • Plantar fasciitis symptoms lasting for at least 3 months
  • Heel pain localized to the plantar-medial calcaneal tubercle
  • First-step pain in the morning or pain during the first steps after a period of rest
  • Roles and Maudsley score of 3 or 4 at the baseline assessment
  • Ability and willingness to provide written informed consent and comply with the study procedures

Exclusion Criteria:

  • Body mass index greater than 30 kg/m²
  • Presence of a clinically relevant cardiopulmonary, dermatological, neurological or musculoskeletal condition other than plantar fasciitis that could affect walking, plantar loading, pain assessment or participation in the study
  • History of foot or ankle surgery
  • Requirement for a walking assistive device during the study assessments
  • Inability or unwillingness to wear footwear compatible with the assigned foot orthoses
  • Cognitive or psychiatric condition that could prevent understanding of the study instructions, provision of informed consent or completion of the assessments
  • Pregnancy

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: CNC-Milled EVA Insole
Participants assigned to this active-comparator arm received a custom-made ethylene-vinyl acetate (EVA) insole manufactured using computer numerical control (CNC) milling and were instructed to use the assigned orthosis for 12 weeks.
A custom-made insole was individually manufactured from ethylene-vinyl acetate (EVA) using computer numerical control (CNC) milling. Participants used the assigned insole for 12 weeks.
Experimental: FDM 3D-Printed TPU Insole
Participants assigned to this experimental arm received a custom-made thermoplastic polyurethane (TPU) insole manufactured using fused deposition modelling (FDM) three-dimensional printing and were instructed to use the assigned orthosis for 12 weeks.
A custom-made insole was individually manufactured from thermoplastic polyurethane (TPU) using fused deposition modelling (FDM) three-dimensional printing. Participants used the assigned insole for 12 weeks.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change From Baseline in Gastrocnemius Muscle Activation During a Standardized 10-Metre Walking Task
Time Frame: Baseline and Week 12
Surface electromyography was recorded bilaterally from the gastrocnemius medialis and gastrocnemius lateralis muscles during a standardized 10-metre walking task. The processed parameters included maximum EMG envelope amplitude and mean-maximum, minimum-peak and maximum-peak activation values normalized to maximum voluntary contraction (%MVC). MVC recordings were obtained during standardized plantar-flexion and dorsiflexion tasks. Higher %MVC values indicate greater muscle activation relative to MVC. The 10-metre walk was used solely as the standardized task for EMG recording and was not evaluated as a walking-performance outcome.
Baseline and Week 12

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change From Baseline in Affected Foot Loading Assessed by Static Pedobarography
Time Frame: Baseline and Week 12
Static pedobarography was performed during quiet standing to quantify plantar load distribution. Rearfoot loading of the affected foot was expressed as a percentage of the total plantar load for that foot, ranging from 0% to 100%, with higher values indicating greater relative rearfoot loading. Affected and unaffected feet were coded before analysis. Because forefoot and rearfoot loading percentages are mathematically complementary, forefoot loading was not treated as a separate independent endpoint.
Baseline and Week 12
Change From Baseline in Foot-Related Function Assessed by the Foot Function Index
Time Frame: Baseline and Week 12
Foot-related function was evaluated using the 23-item Foot Function Index, comprising pain, disability and activity-limitation subscales. Subscale and total scores are expressed on a scale from 0 to 100, with higher scores indicating greater pain, disability or activity limitation.
Baseline and Week 12
Change From Baseline in Pain Intensity Assessed by the Visual Analogue Scale
Time Frame: Baseline and Week 12
Pain intensity was assessed using a 10-cm Visual Analogue Scale ranging from 0 to 10, where 0 indicates no pain and 10 indicates the worst imaginable pain. First-step morning pain, pain during palpation of the plantar heel and pain associated with prolonged standing were recorded and analyzed as separate pain scores.
Baseline and Week 12
Change From Baseline in Plantar Heel Pressure Pain Threshold
Time Frame: Baseline and Week 12
Pressure pain threshold at the plantar heel was measured using a pressure algometer and expressed in kg/cm². Higher values indicate a greater pressure pain threshold and lower pressure sensitivity.
Baseline and Week 12
Participant Satisfaction With the Assigned Insoles Assessed by Quebec User Evaluation of Satisfaction with Assistive Technology (QUEST-2.0).
Time Frame: Week 12
Participant satisfaction was assessed at Week 12 using the Quebec User Evaluation of Satisfaction with Assistive Technology (QUEST 2.0). The 12-item instrument comprises eight items evaluating satisfaction with the assistive device and four items evaluating satisfaction with related services. Each item is scored from 1 (not satisfied at all) to 5 (very satisfied). Device, service and total QUEST scores are calculated by averaging the applicable item scores, with higher scores indicating greater satisfaction. Participants also identify the three satisfaction items they consider most important; these responses were summarized descriptively.
Week 12

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

December 16, 2024

Primary Completion (Actual)

January 6, 2025

Study Completion (Actual)

July 21, 2026

Study Registration Dates

First Submitted

August 19, 2024

First Submitted That Met QC Criteria

August 19, 2024

First Posted (Actual)

August 20, 2024

Study Record Updates

Last Update Posted (Actual)

August 31, 2026

Last Update Submitted That Met QC Criteria

August 26, 2026

Last Verified

August 1, 2026

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

No formal plan was established to share de-identified individual participant data with other researchers.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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