Effects of Squat Variations on Quadriceps Muscle Thickness and Strength

September 9, 2026 updated by: FİLİZ EYÜBOĞLU, Uskudar University

The study was conducted using a randomized controlled trial design. Participants who met the inclusion criteria were randomly assigned to either the "Classic Squat Group" or the "Heel-Elevated Squat Group." Both groups completed an 8-week strength training program consisting of three sessions per week, following the resistance exercise principles recommended by the American College of Sports Medicine. The main component of the program was the assigned squat variation.

Baseline and post-intervention assessments at 8 weeks were performed according to standardized protocols. Exercise sessions were supervised by an experienced physiotherapist to ensure proper technique and minimize injury risk. Training intensity was progressively increased based on participants' adaptation and one-repetition maximum (1-RM) strength levels.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

42

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

  • Turkey (Türkiye)
    • Istanbul
      • Istanbul, Istanbul, Turkey (Türkiye)
        • Uskudar University

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

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • No musculoskeletal, neurological, or cardiopulmonary conditions that would prevent participation in exercise
  • Healthy young adults
  • No regular lower extremity training participation in the last 6 months

Exclusion Criteria:

  • History of surgery or serious injury to the knee, hip, or ankle joints within the past year
  • Presence of any neurological disorder affecting balance or motor control
  • Presence of any cardiovascular or pulmonary disease that contraindicates exercise participation

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: Other
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Tradional Squat Group
Participants performed the tradional squat exercise as part of an 8-week training program.
Other: Tradional Squat Group
Participants completed an 8-week supervised bodyweight squat program performed twice weekly, with progressive increases in training volume and intensity. Squats were performed to approximately parallel depth, using a controlled ~2-s eccentric phase followed by maximal intended concentric velocity, with 2-min rest intervals between sets.
Other Names:
  • Classic Squat Group
Experimental: Heel-Elevated Squat Exercise
Participants performed heel-elevated squat exercise as part of an 8-week training program.
Other: Heel-Elevated Squat Group
Participants in the Heel-Elevated Squat Group performed all repetitions with both heels supported on rigid 5-cm wedges. Participants completed an 8-week supervised bodyweight squat program performed twice weekly, with progressive increases in training volume and intensity. Squats were performed to approximately parallel depth, using a controlled ~2-s eccentric phase followed by maximal intended concentric velocity, with 2-min rest intervals between sets.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Muscle Strength (Isomed 2000 Isokinetic Dynamometer)
Time Frame: Baseline and 8 weeks post-intervention
Quadriceps muscle strength was assessed using a Isomed 2000 isokinetic dynamometer, which is considered a gold-standard method for evaluating muscle performance. Isokinetic testing measures maximal torque produced by the muscle throughout the range of motion at a constant angular velocity, providing reliable data on muscle function. Knee extension strength were evaluated.
Baseline and 8 weeks post-intervention

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Assessment of Muscle Thickness
Time Frame: Baseline and 8 weeks post-intervention
Before measurement, participants rested for 20 minutes, and quadriceps muscle thickness was assessed at the midpoint between the anterior superior iliac spine and the superior pole of the patella using B-mode ultrasonography. Anterior thigh muscle thickness was defined as the distance between the superficial fascia of the rectus femoris and the femoral periosteum, representing the combined thickness of the rectus femoris and vastus intermedius.
Baseline and 8 weeks post-intervention

Collaborators and Investigators

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

Sponsor

Uskudar University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Helpful Links

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)

April 27, 2026

Primary Completion (Actual)

May 4, 2026

Study Completion (Actual)

July 20, 2026

Study Registration Dates

First Submitted

June 15, 2026

First Submitted That Met QC Criteria

July 13, 2026

First Posted (Actual)

July 14, 2026

Study Record Updates

Last Update Posted (Actual)

September 14, 2026

Last Update Submitted That Met QC Criteria

September 9, 2026

Last Verified

September 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • UskudarUUU

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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