What clinical finding is most strongly suggested by gradually worsening hip pain in an athlete with no significant trauma?

Gradually worsening hip pain in an athlete, particularly when not associated with any significant trauma, is most commonly indicative of femoroacetabular impingement (FAI). FAI occurs when there is abnormal contact between the femoral head and the acetabulum, often due to structural issues in the hip joint like a cam or pincer deformity. This condition leads to pain and stiffness over time, especially with certain activities, and is frequently observed in athletes who engage in repetitive hip motions.

The gradual nature of the symptoms aligns closely with FAI, as athletes often experience increasing discomfort that can significantly affect their performance. Unlike acute injuries where trauma is evident, FAI can develop insidiously, making it particularly relevant in the context of the scenario described. The hip pain associated with femoroacetabular impingement typically targets the groin area and may worsen with flexion or internal rotation of the hip, which is common in sports-related movements. Hence, the chronic nature of the pain in this athlete strongly points towards femoroacetabular impingement as the most likely diagnosis.