Dynamic Q Angle and Core Endurance in Adolescent Athletes With Patellofemoral Pain Syndrome

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.

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