Biofeedback-Assisted Short Foot Exercises in Flexible Flatfoot

Evaluation of the Effectiveness of Biofeedback-Assisted Short Foot Exercises in Individuals With Flexible Pes Planus: A Randomized Controlled Trial

The goal of this clinical trial is to compare the effects of biofeedback-assisted short foot exercises and traditional short foot exercises in individuals with flexible pes planus. The study aims to determine whether adding biofeedback to short foot exercises leads to greater improvements in foot biomechanics, balance, and functional ability.

The main questions it aims to answer are:

Does biofeedback-assisted short foot exercise improve plantar pressure distribution and foot posture more than traditional short foot exercise? Does the use of biofeedback result in greater improvements in balance and functional ability? Researchers will compare a biofeedback-assisted short foot exercise program to a traditional short foot exercise program to evaluate their effects on plantar pressure distribution, foot posture, balance, ankle range of motion, and functional outcomes.

Participants will:

Be randomly assigned to either a traditional short foot exercise group or a biofeedback-assisted short foot exercise group Participate in a supervised exercise program twice per week for 6 weeks Complete pre- and post-intervention assessments, including plantar pressure analysis, balance tests, foot posture evaluation, and self-reported functional questionnaires

Study Overview

• Status: Recruiting
• Conditions: Pes Planus
• Intervention / Treatment: Other: Biofeedback assisted exercises; Other: Supervised exercises

Detailed Description

Study Design and Objective

This randomized controlled trial aims to compare the effects of biofeedback-assisted short foot exercises and traditional short foot exercises on plantar pressure distribution, foot posture, balance, and functional ability in individuals with flexible pes planus.

Participants

Voluntary participants aged 10 to 35 years, diagnosed with flexible pes planus, with no history of foot or ankle surgery, fracture, or psychiatric disorder, will be included in the study.

Individuals diagnosed with rigid pes planus, those younger than 10 or older than 35 years, or those with a history of psychiatric illness or lower extremity trauma will be excluded.

Randomization and Groups

Participants will be randomly assigned to two equal groups using a simple randomization method:

Group 1: Short Foot Exercise (SFE) group (without biofeedback)

Group 2: Biofeedback-Assisted Short Foot Exercise (SFE) group

Exercise Intervention

Both groups will participate in a structured 6-week exercise program, performed twice per week, for a total of 12 sessions.

Each session will begin with a 5-minute warm-up period, including:

Towel curl exercises

Resisted ankle movements using a theraband (dorsiflexion, plantar flexion, inversion)

Ball-grasping exercises with the foot

The main intervention, the short foot exercise (SFE), aims to activate the medial longitudinal arch by drawing the first metatarsal head toward the heel without toe flexion. Exercise intensity and body positions will be progressively adjusted throughout the intervention period.

Outcome Measures

Assessments will be conducted before and after the 6-week intervention period using the following outcome measures:

Pedobarographic Analysis: Measurement of plantar pressure distribution (g/cm²) and contact area (cm²) to evaluate plantar load during static stance.

Navicular Drop Test: Measurement of the change in navicular tuberosity height between sitting and standing positions to assess medial longitudinal arch collapse.

Foot Posture Index (FPI-6): Assessment of static foot posture based on six clinical observations, scored from -12 (highly supinated) to +12 (highly pronated).

Y-Balance Test: Evaluation of dynamic balance performance in three directions: anterior, posteromedial, and posterolateral.

Foot and Ankle Ability Measure (FAAM): Self-reported assessment of functional ability using the Activities of Daily Living (ADL) and Sports subscales.

Ankle Range of Motion (ROM): Measurement of ankle dorsiflexion and plantar flexion angles using a goniometer.

Data Analysis

Statistical analyses will be performed using SPSS version 20.0.

Data normality will be assessed using the Shapiro-Wilk test.

Parametric data will be presented as mean ± standard deviation.

Categorical variables will be reported as frequency and percentage.

Between-group comparisons will be conducted using the Independent Samples t-test or the Mann-Whitney U test, depending on data distribution.

Within-group comparisons will be analyzed using the Paired Samples t-test or the Wilcoxon signed-rank test.

Categorical variables will be analyzed using the Pearson chi-square test.

A p-value < 0.05 will be considered statistically significant.

Sample Size Calculation

Sample size and power analysis were performed using the PS-Power and Sample Size program. For the primary outcome measure, the Foot and Ankle Ability Measure (FAAM) score, the minimum clinically important difference (MCID) was set at 8 points, with a standard deviation of 7, based on previously published studies.

Calculations were performed with a 95% confidence level, 80% statistical power, and a significance level of 0.05. The analysis indicated that at least 13 participants per group were required. Considering a potential 20% dropout rate, a total of at least 30 participants (15 per group) will be included in the study.

• Study Type: Interventional
• Enrollment (Estimated): 30
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Taner Alparslan, Physiotherapist; Phone Number: 00902128663700; Email: babaknavid@ogr.iuc.edu.tr
• Study Contact Backup: Name: Sezen KARABÖRKLÜ ARGUT, Asst. Prof. Dr.; Phone Number: 00902128663700; Email: s.karaborkluargut@iuc.edu.tr

Study Locations

• Turkey (Türkiye)
  • Büyükçekmece
    • Istanbul, Büyükçekmece, Turkey (Türkiye), 34500
      • Not yet recruiting
      • Istanbul University-Cerrahpasa
      • Contact: Taner ALPARSLAN; Phone Number: 00905448022480; Email: babaknavid@ogr.iuc.edu.tr
  • Fatih
    • Istanbul, Fatih, Turkey (Türkiye), 34104
      • Recruiting
      • Department of Orthopedics and Traumatology, Istanbul Faculty of Medicine, Istanbul University
      • Contact: Mehmet Demirel, Assistant Professor; Phone Number: (0212) 414 20 00; Email: mehmet.demirel@istanbul.edu.tr

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Voluntary participants aged 18 to 45 years
• Diagnosis of flexible pes planus
• No history of surgery, fracture, or psychiatric disorder

Exclusion Criteria:

• Diagnosis of rigid pes planus
• Age younger than 18 years or older than 45 years
• History of psychiatric disorder or lower extremity trauma

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: BF Group	Other: Biofeedback assisted exercises; Biofeedback-assisted short foot exercise group
Active Comparator: Exerc Group	Other: Supervised exercises; Short foot exercise only group

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The Foot and Ankle Ability Measure (FAAM)	The Foot and Ankle Ability Measure (FAAM) is a validated, self-reported questionnaire designed to assess functional limitations associated with foot and ankle conditions. It consists of two subscales: Activities of Daily Living (ADL) and Sports. Each item is scored on a 5-point Likert scale, ranging from 0 (unable to perform) to 4 (no difficulty). The total score for each subscale is converted to a percentage, with higher scores indicating better functional ability. The FAAM has been shown to be reliable, valid, and responsive to clinical change in individuals with musculoskeletal impairments of the foot and ankle.	Baseline
The Foot and Ankle Ability Measure (FAAM)	The Foot and Ankle Ability Measure (FAAM) is a validated, self-reported questionnaire used to assess functional limitations associated with foot and ankle conditions. It consists of two subscales: Activities of Daily Living (ADL) and Sports. Each item is scored on a 5-point Likert scale, ranging from 0 (unable to perform) to 4 (no difficulty). Total scores for each subscale are converted to percentage scores, with higher values indicating better functional performance. The FAAM has demonstrated good reliability, validity, and responsiveness to clinical change in individuals with musculoskeletal impairments of the foot and ankle.	6 week
Pedobarographic Analysis	Pedobarographic analysis is an objective method used to assess plantar pressure distribution and contact area during static standing or walking. Measurements are obtained using a computerized pressure platform that records static and dynamic foot loading patterns in real time. During the assessment, participants stand or walk barefoot on the pedobarographic platform. The system measures the magnitude and distribution of plantar pressures and contact area across different regions of the foot, including the heel, midfoot, and forefoot. This analysis provides quantitative data on load symmetry, pressure distribution, and medial-lateral balance, which are key indicators of foot biomechanics and medial longitudinal arch function.	Baseline
Pedobarographic Analys	Pedobarographic analysis is an objective method used to assess plantar pressure distribution and contact area during static standing and walking. Measurements are obtained using a computerized pressure platform that records static and dynamic foot-loading patterns in real time. During the assessment, participants stand or walk barefoot on the pedobarographic platform. The system measures the magnitude and distribution of plantar pressures and contact area across different regions of the foot, including the heel, midfoot, and forefoot. This analysis provides quantitative data on load symmetry, pressure concentration, and medial-lateral balance, which are important indicators of foot biomechanics and medial longitudinal arch function.	6 Week

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Active Range of Motion	Active ankle range of motion, including plantarflexion and dorsiflexion, will be measured according to the guidelines described by the American Academy of Orthopaedic Surgeons (AAOS) using a digital goniometer.	Baseline
Active Range of Motion	Active ankle range of motion, including plantarflexion and dorsiflexion, will be measured in accordance with the guidelines of the American Academy of Orthopaedic Surgeons (AAOS) using a digital goniometer.	6 week
FPI-6 (Foot Posture Index-6)	The Foot Posture Index (FPI-6) is a clinical assessment tool used to evaluate static foot posture. It consists of six observational criteria: talar head palpation, curvature above and below the lateral malleolus, calcaneal position in the frontal plane, prominence of the talonavicular joint, height and congruence of the medial longitudinal arch, and forefoot abduction/adduction. Each item is scored on a 5-point scale ranging from -2 (indicating supination) to +2 (indicating pronation), resulting in a total score ranging from -12 to +12. Lower scores indicate a more supinated foot posture, whereas higher scores indicate a more pronated foot posture. A score close to zero represents a neutral foot alignment. Interpretation of Scores; 12 to -5: Highly supinated; 4 to -1: Slightly supinated0 to +5: Neutral6 to +9: Pronated10 to +12: Highly pronated	6 Week
Navicular Drop Test	The Navicular Drop Test is a clinical assessment used to evaluate the degree of medial longitudinal arch collapse by measuring the difference between non-weight-bearing and weight-bearing positions of the foot. During the test, the vertical height of the navicular tuberosity from the floor is measured in both a seated (non-weight-bearing) and a standing (weight-bearing) position using a ruler or digital caliper. The difference between these two measurements, expressed in millimeters (mm), represents the navicular drop value. A greater navicular drop value indicates increased pronation and lowering of the medial longitudinal arch, whereas smaller values suggest a more neutral or supinated foot posture. Outcome Metric Difference in navicular height (mm) between seated and standing positions Interpretation of Results < 5 mm: Minimal or no arch drop (supinated tendency) 5-9 mm: Normal range ≥ 10 mm: Excessive pronation / flatfoot tendency	Baseline
FPI-6 (Foot Posture Index-6)	The Foot Posture Index (FPI-6) is a clinical assessment tool used to evaluate static foot posture. It consists of six observational criteria: talar head palpation, curvature above and below the lateral malleolus, calcaneal position in the frontal plane, prominence of the talonavicular joint, height and congruence of the medial longitudinal arch, and forefoot abduction/adduction. Each item is scored on a 5-point scale, ranging from -2 (indicating supination) to +2 (indicating pronation), resulting in a total score ranging from -12 to +12. Lower scores indicate a more supinated foot posture, whereas higher scores indicate a more pronated foot posture. A score close to zero represents a neutral foot alignment. Interpretation of Scores; 12 to -5: Highly supinated; 4 to -1: Slightly supinated0 to +5: Neutral6 to +9: Pronated10 to +12: Highly pronated	Baseline
Navicular Drop Test	The Navicular Drop Test is a clinical measurement used to assess the degree of medial longitudinal arch collapse by comparing the foot in non-weight-bearing and weight-bearing positions. During the test, the vertical height of the navicular tuberosity from the floor is measured in both a seated (non-weight-bearing) and a standing (weight-bearing) position using a ruler or digital caliper. The difference between these two measurements, expressed in millimeters (mm), represents the navicular drop value. A greater navicular drop value indicates increased pronation and lowering of the medial longitudinal arch, whereas smaller values suggest a more neutral or supinated foot posture. Outcome Metric Difference in navicular height (mm) between seated and standing positions Interpretation of Results < 5 mm: Minimal or no arch drop (supinated tendency) 5-9 mm: Normal range ≥ 10 mm: Excessive pronation / flatfoot tendency	6 week
Y-Balance Test	The Y-Balance Test is a dynamic balance assessment tool used to evaluate an individual's ability to maintain postural control while reaching in multiple directions. The participant stands on one leg at the center of a Y-shaped grid and reaches as far as possible with the contralateral leg in three directions: anterior, posteromedial, and posterolateral. The maximum reach distance for each direction is measured in centimeters (cm) and normalized to leg length to reduce inter-individual variability. The test is performed on both lower extremities, and the mean of three successful trials in each direction is recorded. Greater reach distances indicate better dynamic balance performance, whereas shorter reach distances or asymmetry between limbs may indicate balance deficits. Outcome Metrics: Reach distance (cm) in the anterior, posteromedial, and posterolateral directions Composite Y-Balance Score (%) = [(Anterior + Posteromedial + Posterolateral) / (3 × Limb length)] × 100	Baseline
Y-Balance Test	The Y-Balance Test is a dynamic balance assessment tool used to evaluate an individual's ability to maintain postural control while reaching in multiple directions. The participant stands on one leg at the center of a Y-shaped grid and reaches as far as possible with the contralateral leg in three directions: anterior, posteromedial, and posterolateral. The maximum reach distance for each direction is measured in centimeters (cm) and normalized to leg length to reduce inter-individual variability. The test is performed on both lower extremities, and the mean of three successful trials in each direction is recorded. Greater reach distances indicate better dynamic balance performance, whereas shorter reach distances or asymmetry between limbs may indicate balance deficits. Outcome Metrics Reach distance (cm) in the anterior, posteromedial, and posterolateral directions Composite Y-Balance Score (%) = [(Anterior + Posteromedial + Posterolateral) / (3 × Limb length)] × 100	6 Week

Collaborators and Investigators

• Sponsor: Istanbul University - Cerrahpasa
• Investigators: Principal Investigator: Taner ALPARSLAN, PT, Master's student, Istanbul University - Cerrahpasa; Principal Investigator: Sezen KARABÖRKLÜ ARGUT, Asst. Prof. Dr., Istanbul University - Cerrahpasa

Study record dates

Study Major Dates

• Study Start (Actual): December 22, 2025
• Primary Completion (Estimated): September 22, 2026
• Study Completion (Estimated): October 22, 2026

Study Registration Dates

• First Submitted: December 3, 2025
• First Submitted That Met QC Criteria: December 3, 2025
• First Posted (Actual): December 16, 2025

Study Record Updates

• Last Update Posted (Actual): February 6, 2026
• Last Update Submitted That Met QC Criteria: February 4, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: Short Foot Exercise; Biofeedback Training; Flexible Flatfoot
• Additional Relevant MeSH Terms: Talipes; Musculoskeletal Diseases; Musculoskeletal Abnormalities; Congenital Abnormalities; Lower Extremity Deformities, Congenital; Limb Deformities, Congenital; Foot Deformities; Foot Deformities, Acquired; Foot Deformities, Congenital; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Flatfoot
• Other Study ID Numbers: 0a747ZHs - 2025/689

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No