The adductor longus muscle is a hip abductor muscle found in the inner thigh. This muscle controls the thigh bone's ability to move inward and sideways. This muscle originates in the superior aspect of the pubis, below the pubic tubercle. It inserts at the middle third of the linea aspera of the femur along the medial lip. It adducts and flexes the thigh at the hip, and contributes to lateral and medial rotation of the thigh. All adductor muscles in the thighs pull the legs toward the middle when walking to maintain balance. The adductor longus is one of the major muscles and nerves of the lumbar plexus, along with the adductor brevis, adductor magnus, gracilis, and obturator externus muscles. The adductor longus, adductor magnus, and adductor brevis are the three most powerful muscles of the thigh and all three are ribbon-like muscles, attaching along the femur bone. This long, triangular muscle can become torn, which is commonly known as a groin pull. A strain in the adductor longus muscle can cause difficulty walking, pain at night, and pain while seated.