Adductor Magnus Muscle Anatomy

Location & Overview

The adductor magnus muscle is a large, triangular muscle situated on the inner side of the thigh and it is an important member of the adductor muscle group, which helps move the thigh towards the body’s midline ^{[1] [2] [3]}. This muscle comprises two unique parts: the ‘pubofemoral’ or ‘adductor part’, originating from the ischiopubic ramus (a bone structure connecting the pubic bone and the ischium in the pelvic region), and the ‘ischiocondylar’ or ‘hamstring part’, arising from the ischium (the lower and back portion of the hip bone). The hamstring part exhibits similarities in structure, proximal attachment, and innervation to the hamstring muscles, although it is not an official member of that muscle group, which includes the biceps femoris, semitendinosus, and semimembranosus muscles ^{[4] [5]}. The medial compartment of the thigh houses the pubofemoral or adductor section, while the ischiocondylar or hamstring portion is part of the posterior compartment ^[6].

The adductor magnus muscle is susceptible to pathologies such as strains, tears, and tightness, which can lead to groin pain or limited hip mobility ^{[7] [8]}. Example exercises that target the adductor magnus muscle include sumo squats, wide-stance leg presses, and lateral lunges ^[9] . However, the ‘Copenhagen adduction exercise’ is recognised as one of the most effective ways to strengthen the adductors. One of the reasons for its popularity is its versatility, as it can be performed nearly anywhere using just your bodyweight and an object to support your leg ^{[10] [11] [12]}.

Here we can see the adductor magnus muscle in isolation.

Here we can see the adductor magnus muscle from a superficial view.

Origin & Insertion

The adductor magnus muscle has two distinct portions with different origins and insertions. The ‘pubofemoral’ or ‘adductor’ portion and the ‘ischiocondylar’ or ‘hamstring’ portion ^{[13] [14]}.

The pubofemoral/adductor portion originates from the inferior pubic ramus and the ischial ramus. The inferior pubic ramus is a part of the pubic bone, one of the three bones that make up the pelvis, and the ischial ramus is a thin, flat bone that extends from the ischium, the lower and back part of the hip bone. The pubofemoral/adductor portion of the adductor magnus then inserts onto the linea aspera and medial supracondylar line of the femur. The linea aspera is a long, rough, vertical ridge on the back of the femur, and the medial supracondylar line is a ridge that extends from the linea aspera down to the medial condyle (the rounded prominence at the end of the femur). The portion of the adductor magnus connecting onto the linea aspera also blends with the proximal attachment of the biceps femoris muscle’s short head, allowing the two muscles to work together to stabilise the pelvis and femur[7] ^{[15] [16] [17]}.

The ischiocondylar/hamstring portion of the adductor magnus originates from the ischial tuberosity, a rough, bony projection on the lower and back part of the hip bone. This portion inserts at the adductor tubercle of the femur, a small and bony prominence located on the medial condyle of the femur. The insertion also connects through fibrous attachments to the supracondylar line of the femur ^{[18] [19] [20]}.

Here we can see the origin of the adductor magnus highlighted in red.

Here we can see the proximal insertion of the adductor magnus on the linea aspera and medial supracondylar line of the femur.

Here we can see the distal insertion of the adductor magnus on the adductor tubercle of the femur.

Actions

The adductor magnus muscle has two distinct portions with different actions, the adductor portion, and the hamstring portion. Both parts contribute to the overall function of the muscle ^{[21] [22]}.

The adductor and hamstring portions of the muscle are both involved in hip adduction, which is the action of bringing the leg toward the midline of the body. This movement is useful for activities such as walking, running, or maintaining balance when standing on one leg. The adductor portion of the muscle has an additional role in hip flexion, which is the action of lifting the leg upward in front of the body, as in climbing stairs or kicking a football ^{[23] [24]}. The hamstring portion of the adductor magnus can extend the hip joint, which involves moving the leg backward, away from the body. A good example of hip extension would be skateboarding, where the leg pushes back the ground below to propel the skateboard forwards ^{[25] [26]}.

This image shows an example of hip adduction, which involves moving the towards the body (medially). The opposite of hip abduction is hip abduction. Hip adduction is an action of both the the adductor portion and the hamstring portion of the adductor magnus.

In this image, you can see an example of hip flexion and extension. Hip flexion is the action of raising your leg up in front of you and causing your hip to bend. If both legs are fixed, the torso will lean forward towards the legs. The opposite movement of hip flexion is hip extension. Hip extension is the movement of the thigh or the upper leg backward, away from the body, in the sagittal plane. This action involves increasing the angle between the thigh and the pelvis, causing the hip joint to straighten or extend. Hip flexion is an action of the adductor portion of the adductor magnus, whereas hip extension is an action of the hamstring portion of the adductor magnus.

Innervation

The adductor magnus muscle has a unique innervation pattern because it is composed of two separate portions with distinct functions, each receiving innervation from different nerves ^{[27] [28]}.

The adductor portion (also known as the pubofemoral part) is innervated by the posterior branch of the obturator nerve. The obturator nerve arises from the lumbar plexus, which is formed by the anterior divisions of spinal nerves L2, L3, and L4. This part of the adductor magnus muscle primarily contributes to hip adduction and flexion ^{[29] [30]}.

The hamstring portion (also known as the ischiocondylar part) receives innervation from the tibial division of the sciatic nerve. The sciatic nerve is the largest nerve in the body and originates from the lumbosacral plexus, composed of spinal nerves L4 through S3. This portion of the adductor magnus muscle primarily contributes to hip adduction and extension ^{[31] [32]}.

The dual innervation of the adductor magnus muscle allows it to perform its various actions effectively, as each portion has a specialized function that is controlled by a specific nerve ^{[33] [34] [35]}.

Blood Supply

The primary blood supply source from the adductor magnus is the perforating branches of the profunda femoris artery. The medial femoral circumflex artery supplies the superior portion of the muscle. The femoral artery, genicular arteries and popliteal artery supply the inferior portion of the muscle. The adductor magnus receives a vascular supply from both is posterior and anterior surfaces^[36].