Adductor magnus
The largest adductor, and a serious hip extensor that most people have never heard of.
- Type
- Muscle
- Region
- Thigh
- Standard name
- m. adductor magnus
- Origin
- Inferior pubic ramus, ramus of the ischium, and the ischial tuberosity
- Insertion
- The linea aspera and medial supracondylar line of the femur, and the adductor tubercle
- Actions
- hip adductionhip extension
- Verify
- TA2 2630 TA98 A04.7.02.028
What it is
A very large, triangular muscle occupying the inner thigh, and the biggest of the adductor group. It arises across a wide span of the lower pelvis and inserts along most of the length of the back of the femur, finishing at the adductor tubercle just above the inner knee.
It is really two muscles sharing a name, and this is the key to understanding it. The larger adductor part runs from the pubic and ischial rami out to the linea aspera. The hamstring part arises from the ischial tuberosity — the same sitting bone the hamstrings come from — and runs almost vertically to the adductor tubercle. The two portions have different nerve supplies.
Near the bottom there is a gap in its insertion, the adductor hiatus, through which the femoral artery passes from the front of the thigh to the back.
What it does
Adducts the hip — draws the thigh towards the midline.
And, through its hamstring part, extends the hip powerfully. This is the part people do not expect. That portion has a line of pull and an origin much like a hamstring's, and in terms of contribution to hip extension it is a serious muscle rather than an afterthought.
What loads it
Squatting loads it substantially, particularly at depth, where hip extension demand is highest and the adductors contribute meaningfully to standing back up. The goblet squat and box squat both load it.
Anything requiring the legs to be pulled together against resistance, and lateral movements where a wide stance has to be recovered from.
What is commonly got wrong about it
That the adductors are "inner thigh" toning muscles. The hip adduction machine has done lasting damage to the reputation of a large and genuinely important muscle group. Adductor magnus is one of the larger muscles in the body and a substantial contributor to hip extension.
That squats do not train the inner thigh. They do, and this muscle is a large part of why deep squatting feels different from shallow squatting.
"Groin strain" as a single injury. Injuries around the inner thigh and pubic region involve several possible structures, and distinguishing them requires an examination.