Adductor Magnus (Groin)
Thigh · Lower Limb
The adductor magnus is the largest and deepest muscle of the medial thigh, and it is functionally two muscles in one. Its adductor part arises from the ischiopubic ramus and inserts along the gluteal tuberosity and linea aspera, while its hamstring part arises from the ischial tuberosity and inserts on the adductor tubercle of the femur. The adductor part adducts and flexes the hip, and the hamstring part extends it. This dual character is reflected in its nerve supply: the adductor part is served by the obturator nerve (L2, L3, L4), and the hamstring part by the tibial part of the sciatic nerve (L4).
Origin, Insertion, Action & Nerve
Origin
Adductor part: ischiopubic ramus; Hamstring part: ischial tuberosity
Insertion
Adductor part: gluteal tuberosity and linea aspera; Hamstring part: adductor tubercle of femur
Action
Adduction of hip; adductor part flexes hip, hamstring part extends hip
Nerve
Adductor part: obturator nerve (L2, L3, L4); Hamstring part: tibial part of sciatic nerve (L4)
Attachments explained
The Adductor Magnus (Groin) is defined first by where it attaches. Its origin is the more fixed anchor, usually the proximal or more stable end that stays put during contraction, while its insertion is the more mobile point that is pulled toward the origin when the muscle shortens.
Origin
Adductor part: ischiopubic ramus; Hamstring part: ischial tuberosity
Insertion
Adductor part: gluteal tuberosity and linea aspera; Hamstring part: adductor tubercle of femur
Action & function
When the Adductor Magnus (Groin) contracts, it produces the following movements: Adduction of hip; adductor part flexes hip, hamstring part extends hip.
As part of the Thigh group of the Lower Limb, it works alongside neighbouring muscles to generate smooth, coordinated movement and to stabilise the structures it acts on.
Nerve supply & clinical relevance
The Adductor Magnus (Groin) receives its nerve supply from the Adductor part: obturator nerve (L2, L3, L4); Hamstring part: tibial part of sciatic nerve (L4). This nerve carries fibres from spinal segment(s) L2, L3, L4.
Because a muscle can only contract when its nerve is intact, injury to the Adductor part: obturator nerve or to its spinal roots (L2, L3, L4) can weaken or paralyse the Adductor Magnus (Groin), impairing the movements it normally produces (adduction of hip). This is why knowing the innervation is central to localising nerve lesions in clinical practice.
How to study the Adductor Magnus (Groin) (the OIANS method)
Learn the adductor magnus as a hybrid split between the medial and posterior compartments, because that division explains everything else about it. The adductor part behaves like its neighbours and flexes the hip, while the hamstring part, arising from the ischial tuberosity and reaching the adductor tubercle, extends the hip just like the true hamstrings.
Use its double nerve supply as the standout fact: the obturator nerve (L2, L3, L4) drives the adductor part and the tibial part of the sciatic nerve (L4) drives the hamstring part. Remembering that one muscle straddles two nerves and two functions makes it a reliable and memorable exam point.
Frequently asked questions
Where is the Adductor Magnus (Groin) located?
The Adductor Magnus (Groin) is a muscle of the Thigh group, located in the Lower Limb.
What is the origin of the Adductor Magnus (Groin)?
Adductor part: ischiopubic ramus; Hamstring part: ischial tuberosity
What is the insertion of the Adductor Magnus (Groin)?
Adductor part: gluteal tuberosity and linea aspera; Hamstring part: adductor tubercle of femur
What movements does the Adductor Magnus (Groin) produce?
Adduction of hip; adductor part flexes hip, hamstring part extends hip
What nerve supplies the Adductor Magnus (Groin)?
Adductor part: obturator nerve (L2, L3, L4); Hamstring part: tibial part of sciatic nerve (L4)
Is the Adductor Magnus (Groin) free to study in OIANS?
The Adductor Magnus (Groin) is always free to browse. Its full origin, insertion, action and nerve details are open to everyone in the Muscle Directory. Quiz and Flashcard practice for the Lower Limb is part of the one-time Lifetime upgrade, though; only the Upper Limb decks are free to test yourself on.
Related muscles
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