The adductor magnus is the largest and most powerful adductor, a triangular muscle with two functionally distinct portions that have different nerve supplies and different actions. The adductor part is innervated by the obturator nerve and adducts and medially rotates the hip, while the hamstring part is innervated by the sciatic nerve and extends the hip. The adductor hiatus, a gap in the distal adductor magnus, transmits the femoral vessels into the popliteal fossa.
| Origin | Inferior pubic ramus and ischial ramus; Ischial tuberosity |
|---|---|
| Insertion | Linea aspera and medial supracondylar line of the femur; Adductor tubercle of the medial femoral condyle |
| Nerve Supply | Obturator nerve (L2, L3, L4) for the adductor part; Tibial division of the sciatic nerve (L4) for the hamstring part |
| Blood Supply | Deep femoral artery via perforating branches |
| Actions | Adduction and medial rotation of the hip; Extension of the hip; Together forms the most powerful adductor and a significant hip extensor |
|---|
Its hamstring portion acts effectively as a fourth hamstring, contributing meaningfully to hip extension during running and sprinting, while its adductor portion controls hip abduction eccentrically during the swing phase of gait. This dual role spans the functional territory of two separate muscle groups.
Adductor magnus strains are common in sprinters, particularly at the hamstring portion near the adductor tubercle, and can be confused with distal hamstring pathology because of the proximity of their insertions. The adductor tubercle on the medial femoral condyle is an important surgical landmark for knee approaches. Adductor magnus trigger points refer pain to the medial thigh, groin, and perineum in patterns that can be difficult to distinguish from urological or gynaecological pathology.
The adductor magnus forms the bulk of the medial thigh and is palpable throughout from the ischium to the medial condyle. The adductor tubercle at the hamstring insertion is the firm bony prominence felt at the superior medial femoral condyle.
Tear at the hamstring portion near the adductor tubercle from explosive sprinting or kicking, producing distal medial thigh pain that requires MRI to distinguish from proximal hamstring pathology.
