Ultrasound Examination of the VMO in Patellofemoral Pain Syndrome

February 13, 2026 updated by: Tuğba GÖNEN, Hasan Kalyoncu University

Ultrasonography Examination of the Vastus Medialis Obliquus and Vastus Medialis Longus Muscles in Patellofemoral Pain Syndrome

The aim of this study is to examine in detail the ultrasonographic characteristics of the vastus medialis obliquus and vastus medialis longus muscles in individuals with patellofemoral pain syndrome and to compare these findings with those of healthy individuals. It is anticipated that the results obtained will contribute to a better understanding of the muscle-based mechanisms of PFAS and provide a scientific basis for the development of muscle-specific assessment and intervention strategies in physical therapy and rehabilitation practices.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Detailed Description

Patellofemoral pain syndrome (PFAS) is a musculoskeletal problem characterized by pain in the front of the knee joint, commonly seen in young and physically active individuals. The etiology of PFAS is multifactorial and is associated with abnormal loading of the patella within the femoral trochlear groove, alterations in joint biomechanics, and functional deficiencies of the surrounding soft tissues. These mechanical irregularities in the patellofemoral joint can lead to pain, loss of function, and activity limitations over time. The quadriceps femoris muscle group plays a fundamental role in providing dynamic stability to the patella. The vastus medialis obliquus (VMO) and vastus medialis longus (VML) muscles within this muscle group are critical for controlling the patella medially and maintaining its proper alignment within the femoral groove. It is known that the oblique fiber structure of the VMO muscle provides medial stabilizing force to the patella, while the VML muscle contributes to force production during knee extension and overall patellar guidance with its longer fibers. In individuals with PFAS, delayed activation patterns, decreased muscle strength, and morphological changes in the vastus medialis muscle have been reported. However, it is observed in the literature that the VMO and VML muscles are treated as a single structure in most studies, and the separate morphological characteristics of these two muscles and their relationship with patellofemoral pain have not been sufficiently investigated. However, the different anatomical, biomechanical, and functional characteristics of these muscles necessitate that their roles in PFAS pathophysiology be evaluated separately. Ultrasonography is a non-invasive, reliable, and reproducible imaging method for evaluating the morphological characteristics of muscle tissue and is increasingly used in clinical research. Ultrasonographic evaluation allows for the objective examination of muscle thickness, cross-sectional area, and architectural features, thereby providing important information about structural changes in muscle function. The aim of this study is to examine in detail the ultrasonographic characteristics of the vastus medialis obliquus and vastus medialis longus muscles in individuals with patellofemoral pain syndrome and to compare these findings with healthy individuals. It is anticipated that the results will contribute to the understanding of the muscle-based mechanisms of PFAS and provide a scientific basis for the development of muscle-specific assessment and intervention strategies in physical therapy and rehabilitation practices.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
40

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Turkey (Türkiye)
    • Şahinbey
      • Gaziantep, Şahinbey, Turkey (Türkiye), (505) 090-5846
        • Hasan Kalyoncu 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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Sampling Method

Non-Probability Sample

Study Population

The study will include individuals aged 18-65 who have been diagnosed with patellofemoral pain syndrome, as well as healthy volunteers with similar characteristics in terms of age and gender. The study group will consist of individuals who have applied to a physical therapy and rehabilitation clinic or who have been referred to relevant units. The control group will be selected from healthy volunteers who do not have any knee pain or lower extremity musculoskeletal problems.

Description

Inclusion Criteria:

  • Between the ages of 18 and 65
  • Have had localized pain in the front of the knee for at least the past 3 months
  • Experience pain during activities that require stair climbing, squatting, prolonged sitting, or knee flexion
  • Have been diagnosed with patellofemoral pain syndrome based on clinical evaluation
  • Volunteer to participate in the study and sign the informed consent form

Exclusion Criteria:

  • History of previous surgery on the knee joint
  • History of significant trauma to the knee region within the last 6 months
  • Diagnosis of meniscus, ligament injuries, knee osteoarthritis, or inflammatory rheumatic disease
  • Neurological diseases or systemic diseases affecting the musculoskeletal system
  • Presence of other lower extremity pathologies causing pain at a level that could affect measurements

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

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Study Group
The study will include individuals aged 18-65 who have been diagnosed with patellofemoral pain syndrome, as well as healthy volunteers with similar characteristics in terms of age and gender.
Control group
The study will include individuals aged 18-65 who have been diagnosed with patellofemoral pain syndrome, as well as healthy volunteers with similar characteristics in terms of age and gender.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Ultrasonographic Measurement
Time Frame: through of the study, average 4 months
A B-mode ultrasound device with a high-frequency (7-12 MHz) linear probe will be used to evaluate muscle architecture. Ultrasound is a reliable, reproducible, and non-invasive imaging method for assessing the morphological characteristics of muscle tissue. Ultrasonographic evaluations will be performed by an experienced researcher in musculoskeletal ultrasonography, in a quiet and standard environment. A high-frequency (7-12 MHz) linear probe will be used during measurements. Participants will be placed on the evaluation table in a supine position, with the knee joint fully extended and relaxed. Before measurements, anatomical reference points will be determined using a tape measure, and temporary markings will be made on the skin. Vastus Medialis Obliquus (VMO): VMO muscle thickness measurement will be performed in the region where the oblique orientation of the muscle fibers is prominent, using the upper-medial edge of the patella as a reference. The measurement point will be determ
through of the study, average 4 months

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Hasan Kalyoncu University

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Tuğba GÖNEN, Asisst. Prof. Dr., Hasan Kalyoncu 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.

General Publications

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 (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
February 25, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
April 25, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
June 25, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
February 13, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 13, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
February 20, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
February 20, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 13, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
February 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 2025/161

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

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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