Elite Athletes: Trunk Mobility, Lower Extremity Flexibility, and Functional Balance Across Sports

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.

Inclusion Criteria: * 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 Exclusion Criteria: * 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