Adductor Longus

Introduction

Introduction to Adductor Longus

The adductor longus is the most anteriorly placed muscle of the medial thigh compartment and is a powerful adductor of the hip joint. It is a flat, triangular muscle that arises from the body of the pubis and inserts along the linea aspera of the femur. The adductor longus is an important anatomical landmark, forming the medial border of the femoral triangle, and its tendon is readily palpable in the groin. It is frequently involved in groin strains ('rider's strain'), especially in athletes who engage in rapid changes of direction and kicking. Its innervation by the anterior division of the obturator nerve provides a clinical test for the L2–L4 nerve roots.

Study

1. Origin and Insertion

The adductor longus originates by a strong, round tendon from the anterior surface of the body of the pubis, just inferior to the pubic crest and lateral to the pubic symphysis. The muscle belly expands into a broad, flat aponeurosis that inserts onto the middle third of the linea aspera of the femur.

2. Relations

The adductor longus forms the medial boundary of the femoral triangle, where it lies deep to the femoral vessels and the saphenous nerve. Its medial border is in contact with the gracilis. The anterior surface is covered by the fascia lata. Deep to the adductor longus lie the adductor brevis (proximally) and the adductor magnus (distally). The profunda femoris artery lies on the posterior surface of the adductor longus, separating it from the adductor brevis.

3. Nerve Supply

The adductor longus is innervated by the anterior division of the obturator nerve (L2, L3, L4). The nerve enters the muscle on its deep surface.

4. Blood Supply

The muscle receives its blood supply from the obturator artery and the medial circumflex femoral artery, along with perforating branches of the profunda femoris artery.

5. Actions

The primary action of the adductor longus is adduction of the hip joint. It also assists in flexion and medial rotation of the thigh. When the lower limb is fixed, it helps stabilise the pelvis.

6. Clinical Relevance

Adductor longus strains ('rider's strain') are common in athletes, particularly soccer players and horseback riders, caused by forceful resisted adduction. The proximal tendon is susceptible to tendinopathy and avulsion fractures. The muscle is a key surgical landmark in femoral triangle and groin surgeries. Obturator nerve entrapment or injury leads to weakened adduction and medial thigh wasting.

Summary

Summary of Adductor Longus

The adductor longus is a major hip adductor, originating from the pubis and inserting on the linea aspera. It is innervated by the obturator nerve (L2–L4) and forms the medial border of the femoral triangle. It is commonly injured in groin strains and serves as an important clinical and surgical landmark.