Comparison of Lower Extremity Parameters in Monofin and Bi-fin Swimmers.

Comparison of Lower Extremity Muscle Biomechanical Properties, Joint Range of Motion, and Performance Parameters in Monofin and Bi-fin Swimmers

The purpose of this study is to compare the leg muscle features and joint movements of swimmers who use a single large fin (monofin) versus those who use two fins (bi-fins). Different types of fins change how legs move in the water. This may affect the muscle structure and swimming performance. The researchers want to find out the differences between these two groups of swimmers.

During the study, the researchers will do the following:

Record the age, height, and weight of healthy swimmers who train regularly. Measure the stiffness and flexibility of the leg muscles using MyotonPro device.

Check how well the hips, knees, and ankles can move using digital goniometer.

The findings from this study will help create safer training programs for swimmers. Coaches will use the results to improve swimming performance and lower the risk of leg injuries.

Study Overview

• Status: Active, not recruiting
• Conditions: Lower Extremity Muscles Biomechanical Properties and Joint Range of Motion in Swimmers
• Intervention / Treatment: Device: Measuring of the biomechanical properties of muscles with MyotonPro; Device: Measurement of the length of the lower extremity with a tape measure.; Device: Measuring the range of motion of the lower extremity joints with a digital goniometer

• Study Type: Observational
• Enrollment (Estimated): 42

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Avcılar
    • Istanbul, Avcılar, Turkey (Türkiye), 34310
      • İstanbul Gelisim University

Participation Criteria

Eligibility Criteria

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

• Sampling Method: Probability Sample

Study Population

Young healthy swimmers

Description

Inclusion Criteria:

• Inclusion Criteria:
• Being between 12-18 years old
• Having been involved in at least one swimming style for at least 3 years
• Having participated in at least one competition
• Obtaining parental consent. Obtaining parental consent.

Exclusion Criteria:

• - Having undergone any surgery on the shoulder girdle muscles.
• Having any orthopedic or physical disorder in the shoulder girdle muscles (e.g., frozen shoulder).
• Participating in another sport besides swimming.

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Monofin swimmers	Device: Measuring of the biomechanical properties of muscles with MyotonPro; MyotonPro is used to utilize the biomechanical properties of the muscle. During measurements, the patient will be seated in a chair with back support; the biomechanical properties of the rectus femoris, tibialis anterior, medial gastrocnemius, and hamstring muscles (F - Natural Oscillation Frequency [Hz], Tone or Tension ranges, S - Dynamic Stiffness [N/m], D - Logarithmic Decrease [relative unit], Elasticity increase, R - Mechanical Stress Relaxation Time [ms], C - Relaxation and Deformation Time Ratio [relaxation and deformation time ratio [N/m]) will be measured bilaterally using Myoton PRO. All measurements will be tracked according to the mileage.; Device: Measurement of the length of the lower extremity with a tape measure.; Swimmers' right and left leg lengths (cm) will be measured. All measurements will be tracked in terms of kilometers covered. All measurements will be compared statistically according to pallet types.; Device: Measuring the range of motion of the lower extremity joints with a digital goniometer; Passive range of motion of the lower extremity shoulder joint (flexion, extension, adduction, abduction, external rotation, and internal rotation) will be measured using a digital goniometer. Results will be recorded in degrees (°). All measurements will be compared statistically according to pallet types.
Bi-fin swimmers	Device: Measuring of the biomechanical properties of muscles with MyotonPro; MyotonPro is used to utilize the biomechanical properties of the muscle. During measurements, the patient will be seated in a chair with back support; the biomechanical properties of the rectus femoris, tibialis anterior, medial gastrocnemius, and hamstring muscles (F - Natural Oscillation Frequency [Hz], Tone or Tension ranges, S - Dynamic Stiffness [N/m], D - Logarithmic Decrease [relative unit], Elasticity increase, R - Mechanical Stress Relaxation Time [ms], C - Relaxation and Deformation Time Ratio [relaxation and deformation time ratio [N/m]) will be measured bilaterally using Myoton PRO. All measurements will be tracked according to the mileage.; Device: Measurement of the length of the lower extremity with a tape measure.; Swimmers' right and left leg lengths (cm) will be measured. All measurements will be tracked in terms of kilometers covered. All measurements will be compared statistically according to pallet types.; Device: Measuring the range of motion of the lower extremity joints with a digital goniometer; Passive range of motion of the lower extremity shoulder joint (flexion, extension, adduction, abduction, external rotation, and internal rotation) will be measured using a digital goniometer. Results will be recorded in degrees (°). All measurements will be compared statistically according to pallet types.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Measuring the biomechanical properties of muscles with MyotonPro	Bilaterally Biomechanical properties (F - Natural Oscillation Frequency [Hz], characterizing Tone or Tension, S - Dynamic Stiffness [N/m], D - Logarithmic Decrement [relative unit], characterizing Elasticity, R - Mechanical Stress Relaxation Time [ms], C - Ratio of Relaxation and Deformation time [relative unit], characterizing Creep) of the rectus femoris, tibialis anterior, medial gastrocnemius and hamstring muscles were measured using Myoton PRO. Because the MyotonPRO assessment yields a single-session composite outcome by presenting all relevant units concurrently on the screen, these variables were treated as a whole rather than being documented separately.	From enrollment to the end of treatment at 6 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Measuring the length of lower extremity using a tape measure.	The measuring tape will be used to measure the swimmers' Right and left legs length (cm).	From enrollment to the end of measurements at 6 weeks.
Measuring the range of motion of the lower extremity using a digital goniometer	Passive range of motion of the lower extremity joints (flexion, extension, adduction, abduction, external rotation, and internal rotation) will be measured using a digital goniometer. Results will be recorded in degrees (°)	From enrollment to the end of 6 weeks.

Collaborators and Investigators

• Sponsor: Istanbul Gelisim University

Study record dates

Study Major Dates

• Study Start (Actual): May 2, 2026
• Primary Completion (Estimated): June 15, 2026
• Study Completion (Estimated): June 30, 2026

Study Registration Dates

• First Submitted: May 20, 2026
• First Submitted That Met QC Criteria: June 1, 2026
• First Posted (Actual): June 2, 2026

Study Record Updates

• Last Update Posted (Actual): June 2, 2026
• Last Update Submitted That Met QC Criteria: June 1, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: 27.04.2026-2026/04

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

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