Adductor group (medial thigh)
Musculi adductores femoris
Also known as: adductors, groin muscles, medial compartment of thigh
The muscles of the medial thigh compartment (pectineus, adductor longus, adductor brevis, adductor magnus, gracilis and obturator externus). They adduct the thigh and are supplied mainly by the obturator nerve.
Overview
The adductors fan out from the pubis and ischium to the linea aspera of the femur and the medial tibia, in three layers.
- Anterior layer: pectineus and adductor longus.
- Middle layer: adductor brevis.
- Posterior layer: adductor magnus.
- Gracilis runs the length of the medial thigh, and obturator externus lies deep at the hip.
The obturator nerve (L2–L4) leaves the pelvis through the obturator canal and divides around adductor brevis into anterior and posterior divisions. It supplies the group, with two exceptions: pectineus (femoral nerve) and the hamstring part of adductor magnus (tibial division of the sciatic nerve). The profunda femoris and obturator arteries supply them.
They adduct the thigh and are crucial for stabilising the pelvis on the femur during gait, controlling the swing limb, and for side-stepping, kicking and horse riding. Depending on hip position, several also flex or extend and rotate the thigh. The adductor canal (subsartorial canal), between vastus medialis, adductor longus/magnus and sartorius, carries the femoral vessels and saphenous nerve to the adductor hiatus in adductor magnus.
Parts & subdivisions
- Pecten pubis → pectineal line. Femoral nerve (± obturator).
- Body of the pubis → middle third of the linea aspera.
- Body and inferior ramus of the pubis → pectineal line and upper linea aspera.
- Adductor part and hamstring part. The largest adductor.
- Pubis → medial tibia (pes anserinus). Crosses the knee.
- Obturator membrane → trochanteric fossa. Lateral rotator.
Anatomy
- Origin
Body and inferior ramus of the pubis, ischial ramus and ischial tuberosity.
- Insertion
Pectineal line, linea aspera, medial supracondylar line, adductor tubercle and the medial tibia (gracilis).
- Action
Adduction of the thigh; variable flexion, extension and rotation.
- Innervation
Obturator nerve; femoral nerve (pectineus); tibial division of the sciatic nerve (hamstring part of adductor magnus).
- Nerve roots
L2–L4
- Arterial supply
Profunda femoris artery (and its perforating branches), obturator artery, medial circumflex femoral artery.
Function
- Adduct the thigh
- Stabilise the pelvis and control the limb in gait
- Assist hip flexion (pectineus, longus, brevis) or extension (hamstring part of magnus)
Clinical significance
Groin strain
Adductor longus is the commonest site of groin strain in football and ice hockey. Pain is felt at its pubic origin on resisted adduction (squeeze test).
Obturator nerve injury
Caused by pelvic surgery, tumours or childbirth. It weakens adduction, makes the gait wide-based, and causes numbness over a small area of the medial thigh.
Compiled from standard anatomy and physiology references — see the Muscular System sources. For education only; not medical advice.