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

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.