The adductor longus is a muscle of the groin. It originates on the pubic body just below the pubic crest, and inserts on the middle third of the linea aspera of the femur. It acts on the hip joint to cause adduction and flexion. Distal Trigger points in this muscle refer pain to the upper medial knee and down the tibia. Proximal trigger points refer pain into the anterior hip. These trigger points are the most common muscular cause of groin pain.