Patellofemoral Pain SyndromeNCT07326046
Elite Athletes: Trunk Mobility, Lower Extremity Flexibility, and Functional Balance Across Sports
An observational study of Patellofemoral Pain Syndrome and Anterior Knee Pain, run by Eastern Mediterranean University at 1 site in Cyprus.
Trial summary
This cross-sectional observational study investigated the relationships among dynamic Q angle, core muscle endurance, hip flexibility, and lower extremity functional status in elite adolescent athletes with and without patellofemoral pain syndrome (PFPS). Read more about this study
- Who is it for?
- Ages 15 to 18 yearsHealthy volunteers can take part
- Conditions the study is for
- Patellofemoral Pain Syndrome, Anterior Knee Pain
- How many people
- 0 participants
- Where
- 1 siteCyprus
- Study dates
- 1 Mar 2025to 16 Oct 2025
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 15 to 18 years
- All sexes
- Healthy volunteers accepted
- Child, Adult
Study population: Elite adolescent track-and-field athletes training within national athletic development programs.
Who may be able to join
- Elite adolescent track-and-field athletes aged 15-18 years
- Minimum 2 years of regular training participation
- Training at least 5 days per week
- Ability to complete all assessment procedures
- PFPS group: history of anterior knee pain associated with activity, positive clinical provocation tests, and AKPS score < 80
- Control group: no history of lower extremity pain or functional limitation
Who cannot join
- History of lower extremity surgery or acute injury within the past 6 months
- Neurological, rheumatological, or systemic disease
- Structural deformity of the hip, knee, or ankle
- Ongoing orthopedic rehabilitation or regular analgesic / anti-inflammatory medication use
- Any condition preventing participation in the tests or introducing measurement bias
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Adolescent Elite Athletes: A Comparative Biomechanical Study of Trunk Mobility, Lower Extremity Flexibility, and Functional Balance Across Sports Branches
This cross-sectional observational study investigated the relationships among dynamic Q angle, core muscle endurance, hip flexibility, and lower extremity functional status in elite adolescent athletes with and without patellofemoral pain syndrome (PFPS). A total of 75 track-and-field athletes aged 15-18 years were included, 42 with PFPS and 33 healthy controls. Dynamic Q angle was assessed using a digital goniometric analysis of the step-down test, core endurance was measured with the McGill endurance tests, flexibility was evaluated using the Straight Leg Raise, Modified Thomas, and Ober tests, and functional status was assessed with the Lower Extremity Functional Scale (LEFS).
The study found that athletes with PFPS demonstrated a higher dynamic Q angle, lower core extension and lateral endurance, reduced hip flexor and iliotibial band flexibility, and lower functional scores compared with controls. Regression analyses indicated that hip flexor tightness and functional capacity were significant predictors of the dynamic Q angle in the PFPS group. These findings suggest that PFPS in adolescent athletes is a multidimensional condition influenced by proximal endurance, flexibility, and dynamic alignment rather than isolated knee-level factors.
Read the detailed description
Patellofemoral pain syndrome (PFPS) is a common overuse condition in adolescent athletes and is associated with pain, performance limitations, and reduced participation in sports activities. Increasing evidence suggests that PFPS is not limited to local knee pathology, but is influenced by proximal neuromuscular control, dynamic alignment, and soft-tissue flexibility. The dynamic Q angle, which reflects frontal-plane knee alignment during functional tasks, has been proposed as a clinically meaningful indicator of patellofemoral loading; however, the interaction between dynamic alignment, core endurance, and flexibility parameters in adolescent elite athletes remains insufficiently explored.
This cross-sectional observational study was conducted to examine the relationships among dynamic Q angle, core muscle endurance, hip and lower extremity flexibility, and functional status in elite adolescent athletes with and without PFPS. A total of 75 track-and-field athletes aged 15-18 years were included. Participants were allocated into two groups: athletes diagnosed with PFPS and healthy controls. Dynamic Q angle was assessed using digital two-dimensional video analysis of the step-down test. Core endurance was evaluated using the McGill endurance test battery (flexor, extensor, and lateral plank tests). Flexibility was assessed using the Straight Leg Raise, Modified Thomas, and Ober tests. Functional status was measured with the Lower Extremity Functional Scale (LEFS). All side-dependent measurements were analyzed on the index limb (symptomatic side in the PFPS group and matched limb in controls).
Group differences and correlations among variables were examined, and multiple regression analyses were performed to identify predictors of the dynamic Q angle. The results demonstrated that athletes with PFPS exhibited a significantly higher dynamic Q angle, reduced core extension and lateral endurance, decreased hip flexor and iliotibial band flexibility, and lower functional scores compared with controls. In the PFPS group, hip flexor tightness and functional capacity were significant predictors of the dynamic Q angle, explaining a substantial proportion of its variance.
These findings indicate that PFPS in adolescent athletes represents a multidimensional biomechanical syndrome characterized by the interaction of proximal stability, flexibility restrictions, and dynamic alignment alterations. The study highlights the clinical importance of comprehensive assessment strategies that incorporate core endurance, hip flexibility, and functional performance measures, rather than focusing solely on isolated knee-level factors. The results may contribute to the development of targeted prevention and rehabilitation strategies for adolescent athletes at risk of PFPS.
- Conditions
- Patellofemoral Pain Syndrome, Anterior Knee Pain
- Keywords
- Dynamic Q Angle, ore Endurance, Lower Extremity Function, Adolescent Athletes
- Medical subject headings
- Patellofemoral Pain Syndrome
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| PFPS Group/ Cohort | Adolescent elite athletes diagnosed with patellofemoral pain syndrome. | |
| Control Group | Healthy adolescent elite athletes without anterior knee pain or lower extremity complaints. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Dynamic Q Angle
Dynamic Q angle measured on the index limb during the step-down test using 2-dimensional digital goniometric video analysis. Higher values indicate greater frontal-plane malalignment.
Measured: Single assessment at baseline (cross-sectional).
Core Muscle Endurance - Extension Test
Duration (seconds) of trunk extensor endurance test from the McGill protocol. Longer duration reflects better endurance capacity.
Measured: Single assessment at baseline.
Hip Flexor Flexibility - Modified Thomas Test
Hip flexion angle obtained during the Modified Thomas test on the index limb. Greater angles indicate muscle tightness.
Measured: Baseline, single assessment.
Core Muscle Endurance - Lateral Plank Test
Duration (seconds) of lateral plank endurance on the index limb according to the McGill protocol.
Measured: Single assessment at baseline.
Iliotibial Band / TFL Flexibility - Ober Test
Adduction angle recorded during the Ober test on the index limb. Lower adduction indicates greater tightness.
Measured: Baseline, single assessment.
Hamstring Flexibility - Straight Leg Raise Test
Hip flexion angle at the onset of pelvic compensation during passive straight leg raise. Higher angles reflect better flexibility.
Measured: Single assessment at baseline.
Functional Status - Lower Extremity Functional Scale (LEFS)
Self-reported lower-limb functional capacity scored from 0-80, with higher scores indicating better function.
Measured: Baseline, single assessment.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted8 Jan 2026
- Study start1 Mar 2025
- Primary completion15 Sep 2025
- Study completion16 Oct 2025
Why it stopped: This record was created in duplicate by administrative error. The correct and active registration for this study is NCT07395947.'
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Patellofemoral Pain SyndromeStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case-control
- Time perspective
- Cross-sectional
- Enrolment
- 0 participants (actual)
Sponsor and investigators
- Lead sponsor
- Eastern Mediterranean University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Burçin Uğur Tosun, Eastern Mediterranean University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07326046
- Sponsor's protocol ID
- TEF-BALANCE
- Status last verified
- Sep 2026
- First submitted
- 25 Dec 2025
- Last updated
- 10 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 10 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Adolescent Elite Athletes: A Comparative Biomechanical Study of Trunk Mobility, Lower Extremity Flexibility, and Functional Balance Across Sports Branches
- ClinicalTrials.gov ID
- NCT07326046
- Acronym / sponsor ID
- TEF-BALANCE
- Conditions
- Patellofemoral Pain Syndrome, Anterior Knee Pain
- Keywords
- Dynamic Q Angle, ore Endurance, Lower Extremity Function, Adolescent Athletes
- Study type
- Observational
- Recruitment status
- WithdrawnReason stopped: This record was created in duplicate by administrative error. The correct and active registration for this study is NCT07395947.'
- Enrolment
- 0 participants (actual)
- Lead sponsor
- Eastern Mediterranean UniversityUniversity, hospital or other
- Study start
- 1 Mar 2025 (actual)
- Primary completion
- 15 Sep 2025 (actual)
- Study completion
- 16 Oct 2025 (actual)
- First posted
- 8 Jan 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This cross-sectional observational study investigated the relationships among dynamic Q angle, core muscle endurance, hip flexibility, and lower extremity functional status in elite adolescent athletes with and without patellofemoral pain syndrome (PFPS). A total of 75 track-and-field athletes aged 15-18 years were included, 42 with PFPS and 33 healthy controls. Dynamic Q angle was assessed using a digital goniometric analysis of the step-down test, core endurance was measured with the McGill endurance tests, flexibility was evaluated using the Straight Leg Raise, Modified Thomas, and Ober tests, and functional status was assessed with the Lower Extremity Functional Scale (LEFS).
The study found that athletes with PFPS demonstrated a higher dynamic Q angle, lower core extension and lateral endurance, reduced hip flexor and iliotibial band flexibility, and lower functional scores compared with controls. Regression analyses indicated that hip flexor tightness and functional capacity were significant predictors of the dynamic Q angle in the PFPS group. These findings suggest that PFPS in adolescent athletes is a multidimensional condition influenced by proximal endurance, flexibility, and dynamic alignment rather than isolated knee-level factors.
Detailed description
Patellofemoral pain syndrome (PFPS) is a common overuse condition in adolescent athletes and is associated with pain, performance limitations, and reduced participation in sports activities. Increasing evidence suggests that PFPS is not limited to local knee pathology, but is influenced by proximal neuromuscular control, dynamic alignment, and soft-tissue flexibility. The dynamic Q angle, which reflects frontal-plane knee alignment during functional tasks, has been proposed as a clinically meaningful indicator of patellofemoral loading; however, the interaction between dynamic alignment, core endurance, and flexibility parameters in adolescent elite athletes remains insufficiently explored.
This cross-sectional observational study was conducted to examine the relationships among dynamic Q angle, core muscle endurance, hip and lower extremity flexibility, and functional status in elite adolescent athletes with and without PFPS. A total of 75 track-and-field athletes aged 15-18 years were included. Participants were allocated into two groups: athletes diagnosed with PFPS and healthy controls. Dynamic Q angle was assessed using digital two-dimensional video analysis of the step-down test. Core endurance was evaluated using the McGill endurance test battery (flexor, extensor, and lateral plank tests). Flexibility was assessed using the Straight Leg Raise, Modified Thomas, and Ober tests. Functional status was measured with the Lower Extremity Functional Scale (LEFS). All side-dependent measurements were analyzed on the index limb (symptomatic side in the PFPS group and matched limb in controls).
Group differences and correlations among variables were examined, and multiple regression analyses were performed to identify predictors of the dynamic Q angle. The results demonstrated that athletes with PFPS exhibited a significantly higher dynamic Q angle, reduced core extension and lateral endurance, decreased hip flexor and iliotibial band flexibility, and lower functional scores compared with controls. In the PFPS group, hip flexor tightness and functional capacity were significant predictors of the dynamic Q angle, explaining a substantial proportion of its variance.
These findings indicate that PFPS in adolescent athletes represents a multidimensional biomechanical syndrome characterized by the interaction of proximal stability, flexibility restrictions, and dynamic alignment alterations. The study highlights the clinical importance of comprehensive assessment strategies that incorporate core endurance, hip flexibility, and functional performance measures, rather than focusing solely on isolated knee-level factors. The results may contribute to the development of targeted prevention and rehabilitation strategies for adolescent athletes at risk of PFPS.
Study design
- Observational model
- Case-control
- Time perspective
- Cross-sectional
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| PFPS Group/ Cohort | – | –Adolescent elite athletes diagnosed with patellofemoral pain syndrome. |
| Control Group | – | –Healthy adolescent elite athletes without anterior knee pain or lower extremity complaints. |
Who may qualify
- Ages
- 15 to 18 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult
- Study population
- Elite adolescent track-and-field athletes training within national athletic development programs.
Key inclusion criteria (6 listed)
- Elite adolescent track-and-field athletes aged 15-18 years
- Minimum 2 years of regular training participation
- Training at least 5 days per week
- Ability to complete all assessment procedures
- PFPS group: history of anterior knee pain associated with activity, positive clinical provocation tests, and AKPS score < 80
Key exclusion criteria (5 listed)
- History of lower extremity surgery or acute injury within the past 6 months
- Neurological, rheumatological, or systemic disease
- Structural deformity of the hip, knee, or ankle
- Ongoing orthopedic rehabilitation or regular analgesic / anti-inflammatory medication use
- Any condition preventing participation in the tests or introducing measurement bias
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Dynamic Q Angle
Time frame: Single assessment at baseline (cross-sectional).
Dynamic Q angle measured on the index limb during the step-down test using 2-dimensional digital goniometric video analysis. Higher values indicate greater frontal-plane malalignment.
Core Muscle Endurance - Extension Test
Time frame: Single assessment at baseline.
Duration (seconds) of trunk extensor endurance test from the McGill protocol. Longer duration reflects better endurance capacity.
Hip Flexor Flexibility - Modified Thomas Test
Time frame: Baseline, single assessment.
Hip flexion angle obtained during the Modified Thomas test on the index limb. Greater angles indicate muscle tightness.
Core Muscle Endurance - Lateral Plank Test
Time frame: Single assessment at baseline.
Duration (seconds) of lateral plank endurance on the index limb according to the McGill protocol.
Iliotibial Band / TFL Flexibility - Ober Test
Time frame: Baseline, single assessment.
Adduction angle recorded during the Ober test on the index limb. Lower adduction indicates greater tightness.
Hamstring Flexibility - Straight Leg Raise Test
Time frame: Single assessment at baseline.
Hip flexion angle at the onset of pelvic compensation during passive straight leg raise. Higher angles reflect better flexibility.
Functional Status - Lower Extremity Functional Scale (LEFS)
Time frame: Baseline, single assessment.
Self-reported lower-limb functional capacity scored from 0-80, with higher scores indicating better function.
Results and safety
The study was withdrawn before enrolling participants, so there are no results.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 10 Sep 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Patellofemoral Pain Syndrome and Anterior Knee Pain, run by Eastern Mediterranean University at 1 site in Cyprus.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: withdrawn, as of the sponsor's last update on 10 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Cyprus. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study was withdrawn before enrolling participants, so there are no results.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Dynamic Q Angle (time frame: Single assessment at baseline (cross-sectional).). The study lists 7 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 10 Sep 2026; AzTrials last refreshed its copy on 26 Oct 2026.