Effects of Whole-Body Vibration With Foot Core Exercises: A Randomized Controlled Trial (FoCo-WBV)

Effects of Whole-Body Vibration Combined With Foot Core Exercise Training on Muscle Strength, Balance, and Proprioception in Overweight and Obese Young Adults: A Randomized Controlled Single-Blind Trial

This randomized, single-blind clinical trial investigates whether adding whole-body vibration (WBV) to a supervised foot core exercise program improves ankle muscle strength, balance, and proprioception in overweight and obese young adults (BMI 25.0-39.9 kg/m²). Participants attended 24 face-to-face sessions over 8 weeks (3×/week) under physiotherapist supervision. Outcomes included isometric inversion/eversion strength (hand-held dynamometry) and instrumented balance/proprioception tests (Limits of Stability, mCTSIB, single-leg balance, single-leg proprioception) recorded by a computerized balance analysis system.

Study Overview

• Status: Completed
• Conditions: Obesity & Overweight; Foot and Ankle Disorders
• Intervention / Treatment: Behavioral: Supervised Foot Core Exercise Training (No Vibration); Device: Whole-Body Vibration via DKN Technology Xg-10 Pro

Detailed Description

Design: randomized controlled, single-blind, parallel-group trial conducted at İstinye University Physiotherapy and Rehabilitation Practice & Research Center. Eligible adults (18-35 years; BMI 25-39.9 kg/m²) able to stand barefoot ≥15 s single-leg and perform 5 repetitions of 60° knee-flexion squats without rest were enrolled. Stratified randomization (sex, BMI) with computer sequence (Research Randomizer) and sealed opaque envelopes allocated participants to: (1) Exercise Group (EG): progressive foot core exercises performed on a vibration platform with vibration OFF; (2) WBV-Combined Exercise Group (TEG): identical exercises WITH synchronous whole-body vibration (20-50 Hz; 15-60 s bouts) using a DKN Technology Xg-10 Pro device. Both groups completed 24 supervised sessions across 8 weeks (3×/week). A standardized warm-up/self-massage of the foot/ankle preceded exercises; progression targeted repetitions, active time, and (in TEG) vibration frequency.

Assessments were performed pre- and post-intervention in fixed order with rest intervals. Ankle inversion/eversion strength was measured using a J-Tech Commander Echo digital handheld dynamometer (kg-force). Balance and proprioception were quantified on the PROKIN computerized system (Limits of Stability; mCTSIB; single-leg balance; single-leg proprioception metrics including trunk total standard deviation and mean tracking error).

Statistical plan: normality by Shapiro-Wilk; parametric tests for normally distributed variables (paired t-test within groups; independent t-test between groups), Mann-Whitney U for non-normal age, chi-square for categorical variables; Cohen's d for effect size where within-group change was significant. Analyses in IBM SPSS 25.0. Sample size was estimated a priori for large effect (d=0.8), α=0.05, power=0.80 (planned n=26; 13/group). Post-hoc power for Limits of Stability change in TEG yielded d=0.96, power=0.87. No funding; no conflicts declared.

• Study Type: Interventional
• Enrollment (Actual): 26
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Zeytinburnu
    • Istanbul, Zeytinburnu, Turkey (Türkiye), 3410
      • Istinye University Physiotherapy and Rehabilitation Practice & Research Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• • Age 18-35 years; BMI 25.0-39.9 kg/m².

  • Ability to stand barefoot on a firm surface ≥15 seconds single-leg (one attempt).
  • Ability to perform 5 repetitions of 60° knee-flexion squat without needing rest.
  • Turkish language proficiency for written and verbal communication.

Exclusion Criteria:

• Any medical history requiring regular physician follow-up.

  • Musculoskeletal trauma within the past 12 months.
  • Use within 48 h of medications affecting musculoskeletal performance.
  • Prior surgery or residual deficits from previous trauma.
  • Pregnancy or suspected pregnancy.
  • Any reported contraindication to use of a vibration platform.
  • During study: pain >3/10 on VAS; abnormal blood pressure responses during/after sessions; three consecutive absences; failure to meet progression criteria; incident illness/trauma; withdrawal request.

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
Active Comparator: Exercise Group (EG); Progressive foot core exercise program performed on a vibration platform with vibration disabled; supervised 3×/week for 8 weeks (24 sessions). Standardized warm-up/self-massage, then sequence including foot tapping, bilateral heel raises, arch raises with toe ab/adduction, and single-leg stance on BOSU; progression by repetitions and active time.	Behavioral: Supervised Foot Core Exercise Training (No Vibration); 24 face-to-face sessions over 8 weeks; physiotherapist-led progression in repetitions/active time; performed on DKN Xg-10 Pro with vibration off.; Device: Whole-Body Vibration via DKN Technology Xg-10 Pro; Tri-directional vibration delivered during exercises at 20-50 Hz with 15-60 s stimulus durations per set, progressing across sessions; administered concurrently with the foot core tasks under physiotherapist supervision (total 24 sessions).
Experimental: WBV-Combined Exercise Group (TEG); Identical supervised foot core exercise program performed with whole-body vibration during exercises; same schedule (3×/week, 8 weeks).	Device: Whole-Body Vibration via DKN Technology Xg-10 Pro; Tri-directional vibration delivered during exercises at 20-50 Hz with 15-60 s stimulus durations per set, progressing across sessions; administered concurrently with the foot core tasks under physiotherapist supervision (total 24 sessions).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Limits of Stability (composite score, %)	Composite score from PROKIN computerized balance analysis system; higher scores reflect better voluntary control within stability boundaries; device-generated percentage scale. Safety Issue: No.	Baseline to Week 8

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Single-Leg Balance test (device score)	PROKIN single-leg stance performance metric; device software scoring. Safety Issue: No.	Baseline to Week 8
Modified Clinical Test of Sensory Interaction on Balance (mCTSIB)	PROKIN mCTSIB composite index; lower sway indicates better stability; device software	Baseline to Week 8
Ankle Strength (kg-force)	Maximal isometric eversion and inversion measured with J-Tech Commander Echo handheld dynamometer; each limb tested in standardized position; result recorded in kg-force. Safety Issue: No.	Baseline to Week 8
Single-Leg Proprioception	ROKIN single-leg proprioception protocol; trunk sway variability (total SD) computed by device software; lower values reflect more stable proprioceptive control.PROKIN target-tracking error in single-leg proprioception task; lower is better. Safety Issue: No.	Baseline to Week 8

Collaborators and Investigators

• Sponsor: Istinye University

Study record dates

Study Major Dates

• Study Start (Actual): February 1, 2025
• Primary Completion (Actual): June 30, 2025
• Study Completion (Actual): July 30, 2025

Study Registration Dates

• First Submitted: April 22, 2026
• First Submitted That Met QC Criteria: April 22, 2026
• First Posted (Actual): April 29, 2026

Study Record Updates

• Last Update Posted (Actual): April 29, 2026
• Last Update Submitted That Met QC Criteria: April 22, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Balance; Whole Body Vibration; Proprioseption; Foot Core
• Additional Relevant MeSH Terms: Nutrition Disorders; Overnutrition; Body Weight; Pathological Conditions, Signs and Symptoms; Nutritional and Metabolic Diseases; Signs and Symptoms; Overweight; Obesity
• Other Study ID Numbers: KubraYikilmazTez 24-252

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