The adductor magnus is a big muscle shaped like a triangle and located on the medial section of the thigh. It contracts and forces the hip towards the midline of the body, thereby facilitating activities like sprinting, walking, and other bipedal movements. The muscle also plays a role in hip extension.
The adductor magnus muscle is made up of 2 parts. The section which arises from the ischium’s tuberosity is known as the hamstring section or ischiocondylar portion, while the section arising from the ischiopubic ramus is referred to as adductor minimus, or pubofemoral portion, or adductor portion. Because of the common action, innervation, embryonic origin, the ischiocondylar section is usually regarded as part of the group of hamstring muscles. The pubofemoral section of the adductor magnus is regarded as medial compartment muscle of the thigh, while the ischiocondylar portion is regarded as posterior compartment muscle.
Adductor magnus – Structure and Function
- The Ischiocondylar section: It is mainly made up of fibers that arise from the ischium’s tuberosity. The medial section of the adductor magnus forms a fleshy thick mass made up of rough muscle bundles that go downwards almost vertically and finish in a circular tendon in the inferior third section of the thigh. The tendon inserts into the adductor tubercle present on the femur’s medial condyle and attaches via a fibrous extension to the line which ascends to the linea aspera from the tubercle.
- Pubofemoral section: The fibers of the pubofemoral portion of the adductor magnus muscle, arising from pubis ramus are horizontally directed, short, and inserted into the femur’s coarse line, running medially to the gluteus maximus, to the linea aspera from the greater trochanter. The fibers originating from the ischium’s ramus run in the downward direction and laterally with varied angles of obliquity. They then get inserted via a wide aponeurosis, into the linea aspera as well as the superior section of its medial prolongation occurring below.
- Innervation of the adductor magnus: The hamstring and adductor sections of the adductor magnus muscle are innervated by 2 varied nerves thereby making it a composite nerve. The latter is innervated by the obturator nerve’s posterior division, while the tibial nerve innervates the former.
- Relations of the adductor magnus: On its back surface, the adductor magnus muscle has connections with the semimembranosus, semitendinosus, gluteus maximus, and biceps muscle.
- On its front surface, it has connections with the adductor brevis, pectineus, adductor longus, profunda vein and artery, femoral vein and artery, and with their branches, as well as with the back branches of the obturator vein, obturator artery, and obturator nerve.
- With the quadratus femoris and the obturator externus on its upper margins.
- With the sartorius and gracilis on its inner margins.
- Osseoaponeurotic openings: There are many osseoaponeurotic orifices at the insertion point of the adductor magnus muscle which develop due to attachment of the tendinous arches to the bone. The anterior 4 openings are tiny and act as a passageway for the profunda femoris artery’s perforating branches. The adductor hiatus, or the lowest opening, is big and allows the passage of the femoral vessels into the popliteal fossa.
- Function: The adductor magnus muscle becomes active, especially when the legs are spread and moved into a wide position wherein the legs lie parallel to one another. The section connect to the linea aspera functions as a side rotator. When the leg is flexed and rotated outwards, then the section of the adductor magnus which connects to the medial epicondyle functions as a medial rotator as well as helps extend the joint of the hips.
Adductor magnus – Pain and other problems
Abductor pain and other problematic symptoms usually occur due to a tear or rupture in the muscle or a groin pull or groin strain. The associated pain can be mild or severely debilitating, dull or sharp.
- Causes: Adductor magnus muscles rupture or tear typically occurs when suddenly changing walking directions, sprinting, or quick leg motion against resistance, like kicking a soccer ball. The tear is more likely to occur is a person has not performed sufficient warm up exercises before playing the sport. Recurrent overuse of the muscles in the groin can cause the adductor magnus muscles to become inflamed and develop into adductor tendinopathy.
- Symptoms: Depending on the severity of the groin strain, patients may experience a sudden sharp pain in the groin area, either in the abdominal muscles or higher. There may also be rapid inflammation and swelling and eventually development of bruising.
- Trigger points in the upper section of the muscle can cause pain within the pelvic area. Such pain may be muted or it may be an explosion of sharp pain in the pubic bone, rectum, vagina, bladder, or prostate.
- Trigger points in the middle section of the muscle can cause pain in inner thigh region extending from the groin to nearly the knee. Outward spreading of the thigh can intensify the pain.
- Increased tightness of the adductor magnus trigger points can lead to entrapment of the femoral vein and artery as well as the saphenous nerve, thereby adversely affected the blood flow to the lower limbs and causing neurological difficulties.
- Patients may also experience reduced flexibility and weakness, which in turn can affect the femur stabilization functions of the adductor magnus muscle. Subsequently, the legs tend to deviate laterally or buckle, thereby causing the muscles present on the outer section of the thigh and hip to shorten and contract and finally resulting in pain in these areas.
- Treatment: Sudden onset acute adductor magnus pain need to be promptly treated, as non-treatment can result in recurrence of the tear or rupture, eventually resulting in long-term and chronic groin pain.
- Adductor magnus muscle pain and injury needs to be initially managed via P.R.I.C.E., i.e., protection, rest, ice, compression, and elevation. Patients need to avoid activities that cause pain. Doctors may suggest the use of crutches for the first few days to ease pain. Steroid injections as a treatment option for tendon rupture should be avoided.
- Some common treatment options include cold therapy, wearing a compression bandage or a groin support, strapping or taping the groin with an elastic adhesive bandage, sports massage by a therapist, and strengthening and stretching exercises.
- Surgical repair of the adductor magnus muscle tear or rupture is tried only after the above mentioned traditional methods fail to heal it.