This observational, cross-sectional study aimed to compare dynamic Q-angle, trunk/core endurance, and lower-extremity flexibility between elite adolescent female and male sprinters with and without patellofemoral pain syndrome (PFPS). Participants were classified according to sex and PFPS status. Dynamic Q-angle was assessed during a standardized step-down task, trunk endurance was evaluated using McGill flexion, extension, and lateral endurance tests, and lower-extremity flexibility was assessed using the Straight Leg Raise, Modified Thomas, and Ober tests. The study also examined whether sex and PFPS status were independently associated with dynamic Q-angle. No therapeutic or experimental intervention was administered.
Who can participate
Age range
15 Years – 17 Years
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion Criteria:
Female or male adolescent elite sprinters aged 15-17 years Minimum of two years of regular athletic training Participation in athletic training at least four days per week Possession of a valid track and field license Active participation in sprint events at the national or international level Ability to complete all clinical and biomechanical assessments Written informed consent from the participant and a parent or legal guardian
PFPS Group-Specific Criteria:
Diagnosis of patellofemoral pain syndrome by a sports medicine physician Anterior knee pain localized to the patellofemoral region Positive patellar compression and grind test Anterior Knee Pain Scale score below 80 Visual Analog Scale pain score of at least 3
Control Group-Specific Criteria:
No current anterior knee pain No clinical findings consistent with patellofemoral pain syndrome
Exclusion Criteria:
History of lower-extremity surgery Acute lower-extremity injury within the previous six months Notable musculoskeletal deformity Arthritis or chronic pain affecting the knee, hip, or ankle Neurological or systemic disease that could affect movement or physical performance Inability to complete the assessments because of excessive pain or insufficient cooperation Incomplete assessment data
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
Dynamic Q-Angle During the Step-Down Test (degrees)
Timeframe: Baseline (single assessment at study enrollment)