The adductor magnus is a large triangular muscle, situated on the medial side of the thigh. It consists of two parts. The portion which arises from the ischiopubic ramus (a small part of the inferior ramus of the pubis, and the inferior ramus of the ischium) is called the pubofemoral portion, adductor portion, or adductor minimus, and the portion arising from the

tuberosity of the ischium The ischial tuberosity (or tuberosity of the ischium, tuber ischiadicum), also known colloquially as the sit bones or sitz bones, or as a pair the sitting bones, is a large posterior (anatomy), posterior bone, bony protuberance on the superior r ...

is called the ischiocondylar portion, extensor portion, or "hamstring portion". Due to its common embryonic origin, innervation, and action the ischiocondylar portion (or hamstring portion) is often considered part of the

hamstring A hamstring () is any one of the three posterior thigh muscles in human anatomy between the hip and the knee: from medial to lateral, the semimembranosus, semitendinosus and biceps femoris. Etymology The word " ham" is derived from the Old ...

group of muscles. The ischiocondylar portion of the adductor magnus is considered a muscle of the posterior compartment of the thigh while the pubofemoral portion of the adductor magnus is considered a muscle of the medial compartment.

Structure

Pubofemoral (adductor) portion

Those fibers which arise from the ramus of the pubis are short, horizontal in direction, and are inserted into the rough line of the

femur The femur (; : femurs or femora ), or thigh bone is the only long bone, bone in the thigh — the region of the lower limb between the hip and the knee. In many quadrupeds, four-legged animals the femur is the upper bone of the hindleg. The Femo ...

leading from the greater trochanter to the linea aspera, medial to the gluteus maximus. Those fibers from the ramus of the ischium are directed downward and laterally with different degrees of obliquity, to be inserted, by means of a broad aponeurosis, into the linea aspera and the upper part of its medial prolongation below.

Ischiocondylar (hamstring) portion

The medial portion of the muscle, composed principally of the fibers arising from the tuberosity of the ischium, forms a thick fleshy mass consisting of coarse bundles which descend almost vertically, and end about the lower third of the thigh in a rounded tendon which is inserted into the adductor tubercle on the medial condyle of the femur, and is connected by a fibrous expansion to the line leading upward from the tubercle to the linea aspera.

Relations

By its anterior surface the adductor magnus is in relation with the pectineus, adductor brevis, adductor longus, femoral artery and vein, profunda artery and vein, with their branches, and with the posterior branches of the obturator artery, obturator vein and obturator nerve. By its posterior surface with the semitendinosus, semimembranosus,

biceps The biceps or biceps brachii (, "two-headed muscle of the arm") is a large muscle that lies on the front of the upper arm between the shoulder and the elbow. Both heads of the muscle arise on the scapula and join to form a single muscle bel ...

, and gluteus maximus muscle. By its inner border with the gracilis and sartorius. By its upper border with the obturator externus, and quadratus femoris.

Nerve supply

It is a composite muscle as the adductor and hamstring portions of the muscle are innervated by two different nerves. The adductor portion is innervated by the posterior division of the obturator nerve while the hamstring portion is innervated by the sciatic nerve.

Osseoaponeurotic openings

At the insertion of the muscle, there is a series of osseoaponeurotic openings, formed by tendinous arches attached to the bone. The upper four openings are small, and give passage to the perforating branches of the profunda femoris artery. The lowest (often referred to as the adductor hiatus) is large, and transmits the femoral vessels to the popliteal fossa.

Variation

The upper, lateral part of the adductor magnus is an incompletely separated division often considered a separate muscle — the adductor minimus. These two muscles are frequently separated by a branch of the superior perforating branch of the profunda femoris artery.Bergman, Ronald A.; Afifi, Adel K.; Miyauchi, Ryosuke (2010)
''Adductor Minimus (Henle, Günther)''
Anatomy Atlases

Function

The adductor magnus is a powerful adductor of the thigh, made especially active when the legs are moved from a wide spread position to one in which the legs parallel each other. The part attached to the '' linea aspera'' acts as a lateral rotator. The part which reaches the medial epicondyle acts as a medial rotator when the leg is rotated outwards and flexed, and also acts to extend the hip joint.Platzer, Werner (2004),
Color Atlas of Human Anatomy, Vol. 1, Locomotor System
', Thieme, 5th ed, p 242

Other animals

In other

tetrapods A tetrapod (; from Ancient Greek τετρα- ''(tetra-)'' 'four' and πούς ''(poús)'' 'foot') is any four- limbed vertebrate animal of the clade Tetrapoda (). Tetrapods include all extant and extinct amphibians and amniotes, with the lat ...

, the adductor magnus crosses the knee joint and inserts into the tibia. In humans, the distal part of the tendon detaches and becomes the medial collateral ligament of the knee. Because of this, the medial collateral ligament of the knee in humans may contain a few muscle fibres as an atavistic variation.Norman Eizenberg et al., ''General Anatomy: Principles and Applications'' (2008), p 53.

Additional images

File:Gray430.png, Muscles of the iliac and anterior femoral regions. File:Gray432 color.png, Cross-section through the middle of the thigh. File:Gray433.png, Deep muscles of the medial femoral region. File:Gray544.png, The arteries of the gluteal and posterior femoral regions. File:Slide4rrr.JPG, Adductor magnus muscle File:Slide4WWWW.JPG, Adductor magnus muscle File:Slide1BOUA.JPG, Muscles of thigh. Anterior views. File:Slide1DEEA.JPG, Muscles of thigh. Anterior views.

References

External links

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PTCentral
{{Authority control Hip adductors Thigh muscles Medial compartment of thigh