vertebrate Vertebrates () are animals with a vertebral column (backbone or spine), and a cranium, or skull. The vertebral column surrounds and protects the spinal cord, while the cranium protects the brain. The vertebrates make up the subphylum Vertebra ...

anatomy Anatomy () is the branch of morphology concerned with the study of the internal structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old scien ...

, the hip, or coxaLatin ''coxa'' was used by

Celsus Celsus (; , ''Kélsos''; ) was a 2nd-century Greek philosopher and opponent of early Christianity. His literary work '' The True Word'' (also ''Account'', ''Doctrine'' or ''Discourse''; Greek: )Hoffmann p.29 survives exclusively via quotati ...

in the sense "hip", but by

Pliny the Elder Gaius Plinius Secundus (AD 23/24 79), known in English as Pliny the Elder ( ), was a Roman Empire, Roman author, Natural history, naturalist, and naval and army commander of the early Roman Empire, and a friend of the Roman emperor, emperor Vesp ...

in the sense "hip bone" (Diab, p 77) (: ''coxae'') in

medical terminology Medical terminology is a language used to precisely describe the human body including all its components, processes, conditions affecting it, and procedures performed upon it. Medical terminology is used in the field of medicine. Medical terminolo ...

, refers to either an anatomical region or a

joint A joint or articulation (or articular surface) is the connection made between bones, ossicles, or other hard structures in the body which link an animal's skeletal system into a functional whole.Saladin, Ken. Anatomy & Physiology. 7th ed. McGraw- ...

on the outer (lateral) side of the

pelvis The pelvis (: pelves or pelvises) is the lower part of an Anatomy, anatomical Trunk (anatomy), trunk, between the human abdomen, abdomen and the thighs (sometimes also called pelvic region), together with its embedded skeleton (sometimes also c ...

. The hip region is located

lateral Lateral is a geometric term of location which may also refer to: Biology and healthcare * Lateral (anatomy), a term of location meaning "towards the side" * Lateral cricoarytenoid muscle, an intrinsic muscle of the larynx * Lateral release ( ...

and

anterior Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position pro ...

to the

gluteal region The gluteal muscles, often called glutes, are a group of three muscles which make up the gluteal region commonly known as the buttocks: the gluteus maximus muscle, gluteus maximus, gluteus medius muscle, gluteus medius and gluteus minimus muscl ...

, inferior to the

iliac crest The crest of the ilium (or iliac crest) is the superior border of the wing of ilium and the superolateral margin of the greater pelvis. Structure The iliac crest stretches posteriorly from the anterior superior iliac spine (ASIS) to the posterio ...

, and lateral to the

obturator foramen The obturator foramen is the large, Bilateral symmetry, bilaterally paired opening of the bony pelvis. It is formed by the pubis and ischium. It is mostly closed by the obturator membrane except for a small opening, the obturator canal, through wh ...

, with

muscle tendon A tendon or sinew is a tough band of dense fibrous connective tissue that connects muscle to bone. It sends the mechanical forces of muscle contraction to the skeletal system, while withstanding tension. Tendons, like ligaments, are made of ...

s and

soft tissue Soft tissue connective tissue, connects and surrounds or supports internal organs and bones, and includes muscle, tendons, ligaments, Adipose tissue, fat, fibrous tissue, Lymphatic vessel, lymph and blood vessels, fasciae, and synovial membranes.� ...

s overlying the

greater trochanter The greater trochanter of the femur is a large, irregular, quadrilateral eminence and a part of the skeletal system. It is directed lateral and medially and slightly posterior. In the adult it is about 2–4 cm lower than the femoral head.Sta ...

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 ...

. In adults, the three pelvic bones ( ilium,

ischium The ischium (; : is ...

and pubis) have fused into one

hip bone The hip bone (os coxae, innominate bone, pelvic bone or coxal bone) is a large flat bone, constricted in the center and expanded above and below. In some vertebrates (including humans before puberty) it is composed of three parts: the Ilium (bone) ...

, which forms the superomedial/deep wall of the hip region. The hip joint, scientifically referred to as the acetabulofemoral joint (''art. coxae''), is the

ball-and-socket joint The ball-and-socket joint (or spheroid joint) is a type of synovial joint in which the ball-shaped surface of one rounded bone fits into the cup-like depression of another bone. The distal bone is capable of motion around an indefinite number of ...

between the pelvic

acetabulum The acetabulum (; : acetabula), also called the cotyloid cavity, is a wikt:concave, concave surface of the pelvis. The femur head, head of the femur meets with the pelvis at the acetabulum, forming the Hip#Articulation, hip joint. Structure The ...

and the

femoral head The femoral head (femur head or head of the femur) is the highest part of the thigh bone (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 ...

. Its primary function is to support the weight of the

torso The torso or trunk is an anatomical terminology, anatomical term for the central part, or the core (anatomy), core, of the body (biology), body of many animals (including human beings), from which the head, neck, limb (anatomy), limbs, tail an ...

in both static (e.g.

standing Standing, also referred to as orthostasis, is a position in which the body is held in an upright (orthostatic) position and supported only by the feet. Although seemingly static, the body rocks slightly back and forth from the ankle in the ...

) and dynamic (e.g.

walking Walking (also known as ambulation) is one of the main gaits of terrestrial locomotion among legged animals. Walking is typically slower than running and other gaits. Walking is defined as an " inverted pendulum" gait in which the body vaults o ...

running Running is a method of terrestrial locomotion by which humans and other animals move quickly on foot. Running is a gait with an aerial phase in which all feet are above the ground (though there are exceptions). This is in contrast to walkin ...

) postures. The hip joints have very important roles in retaining balance, and for maintaining the pelvic inclination angle. Pain of the hip may be the result of numerous causes, including nervous, osteoarthritic, infectious, traumatic, and genetic.

Structure

Region

The hip joint, also known as a ball and socket joint, is formed by the acetabulum of the pelvis and the femoral head, which is the top portion of the thigh bone (femur). It allows for a wide range of movement and stability in the lower body. The proximal femur is largely covered by muscles and, as a consequence, the

is often the only palpable bony structure in the hip region.''Thieme Atlas of Anatomy'' (2006), p 381

Articulation

The

hip joint In vertebrate anatomy, the hip, or coxaLatin ''coxa'' was used by Celsus in the sense "hip", but by Pliny the Elder in the sense "hip bone" (Diab, p 77) (: ''coxae'') in medical terminology, refers to either an anatomical region or a joint o ...

or coxofemoral joint is a ball and socket

synovial joint A synovial joint, also known as diarthrosis, joins bones or cartilage with a fibrous joint capsule that is continuous with the periosteum of the joined bones, constitutes the outer boundary of a synovial cavity, and surrounds the bones' articulati ...

formed by the articulation of the rounded head of the femur and the cup-like

of the pelvis. The socket of the acetabulum is pointing downwards and anterolaterally. The socket is also turned such that the outer edge of its roof is more lateral than outer edge of the floor. It forms the primary connection between the bones of the lower limb and the

axial skeleton The axial skeleton is the core part of the endoskeleton made of the bones of the head and trunk of vertebrates. In the human skeleton, it consists of 80 bones and is composed of the skull (28 bones, including the cranium, mandible and the midd ...

of the trunk and pelvis. Both joint surfaces are covered with a strong but lubricated layer called articular hyaline

cartilage Cartilage is a resilient and smooth type of connective tissue. Semi-transparent and non-porous, it is usually covered by a tough and fibrous membrane called perichondrium. In tetrapods, it covers and protects the ends of long bones at the joints ...

. The cuplike acetabulum forms at the union of three pelvic bones — the ilium, pubis, and

ischium The ischium (; : is ...

.Faller (2004), pp 174-175 The Y-shaped growth plate that separates them, the

triradiate cartilage The triradiate cartilage (in Latin cartilago ypsiloformis) is the Y-shaped epiphyseal plate between the ilium, ischium and pubis to form the acetabulum of the os coxae. Human development In children, the triradiate cartilage closes at an appr ...

, is fused definitively at ages 14–16.''Thieme Atlas of Anatomy'' (2006), p 365 It is a special type of spheroidal or

ball and socket joint The ball-and-socket joint (or spheroid joint) is a type of synovial joint in which the ball-shaped surface of one rounded bone fits into the cup-like depression of another bone. The distal bone is capable of motion around an indefinite number of ...

where the roughly spherical femoral head is largely contained within the acetabulum and has an average radius of curvature of 2.5 cm.''Thieme Atlas of Anatomy'' (2006), p 378 The acetabulum grasps almost half the femoral ball, a grip deepened by a ring-shaped fibrocartilaginous lip, the

acetabular labrum The acetabular labrum (glenoidal labrum of the hip joint or cotyloid ligament in older texts) is a fibrocartilaginous ring which surrounds the circumference of the acetabulum of the hip, deepening the acetabulum. The labrum is attached onto the bo ...

, which extends the joint beyond the equator. The centre of the acetabulum (fovea) does not articulate to anything. Instead, it is lined with fat pad and attached to ligamentum teres. The acetabular labrum is horse-shoe shaped. Its inferior notch is bridged by transverse acetabular ligament. The joint space between the femoral head and the superior acetabulum is normally between 2 and 7 mm. The head of the femur is attached to the shaft by a thin neck region that is often prone to fracture in the elderly, which is mainly due to the degenerative effects of

osteoporosis Osteoporosis is a systemic skeletal disorder characterized by low bone mass, micro-architectural deterioration of bone tissue leading to more porous bone, and consequent increase in Bone fracture, fracture risk. It is the most common reason f ...

. The acetabulum is oriented inferiorly, laterally and anteriorly, while the femoral neck is directed superiorly, medially, and slightly anteriorly.

Articular angles

Acetabular angle (or Sharp's angle) is the angle between the horizontal line passing through the inferior aspects of triradiate cartilages (

Hilgenreiner's line Hilgenreiner's line is a horizontal line drawn on an AP radiograph of the pelvis running between the inferior aspects of both triradiate cartilages of the acetabulum The acetabulum (; : acetabula), also called the cotyloid cavity, is a wikt:co ...

) and another line passing through the inferior angle of triradiate cartilage to superior acetabular rim. The angle measures 35 degrees at birth, 25 degrees at one year of age, and less than 10 degrees by 15 years of age. In adults the angle can vary from 33 to 38 degrees. The sagittal angle of the acetabular inlet is an angle between a line passing from the anterior to the posterior acetabular rim and the sagittal plane. It measures 7° at birth and increases to 17° in adults. Wiberg's centre-edge angle (CE angle) is an angle between a vertical line and a line from the centre of the femoral head to the most lateral part of the acetabulum,Page 131
in: as seen on an

anteroposterior Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position provi ...

radiograph Radiography is an imaging technique using X-rays, gamma rays, or similar ionizing radiation and non-ionizing radiation to view the internal form of an object. Applications of radiography include medical ("diagnostic" radiography and "therapeu ...

.
The vertical-centre-anterior margin angle (VCA) is an angle formed from a vertical line (V) and a line from the centre of the femoral head (C) and the anterior (A) edge of the dense shadow of the subchondral bone slightly posterior to the anterior edge of the acetabulum, with the radiograph being taken from the ''false angle'', that is, a lateral view rotated 25 degrees towards becoming frontal. The articular cartilage angle (AC angle, also called ''acetabular index'' or Hilgenreiner angle) is an angle formed parallel to the weight bearing dome, that is, the acetabular '' wikt:sourcil, sourcil'' or "roof", and the horizontal plane, or a line connecting the corner of the triangular cartilage and the lateral acetabular rim. In normal hips in children aged between 11 and 24 months, it has been estimated to be on average 20°, ranging between 18° and 25°. It becomes progressively lower with age. Suggested cutoff values to classify the angle as abnormally increased include: :*30° up to 4 months of age.Page 942
in: :*25° up to 2 years of age.

Femoral neck angle

The angle between the longitudinal axes of the femoral neck and shaft, called the caput-collum-diaphyseal angle or CCD angle, normally measures approximately 150° in newborn and 126° in adults (''coxa norma'').''Thieme Atlas of Anatomy'' (2006), p 367 An abnormally small angle is known as ''

coxa vara Coxa vara is a deformity of the hip, whereby the angle between the head and the shaft of the femur is reduced to less than 120 degrees. This results in the leg being shortened and the development of a limp. It may be congenital and is commonly ...

'' and an abnormally large angle as ''

coxa valga Coxa valga is a deformity of the hip where the angle formed between the head and neck of the femur and its shaft is increased, usually above 135 degrees. The deformity may develop in children with neuromuscular disorders (i.e. cerebral palsy, spi ...

''. Because changes in shape of the femur naturally affects the knee, ''coxa valga'' is often combined with ''

genu varum Genu varum (also called bow-leggedness, bandiness, bandy-leg, and tibia vara) is a varus deformity marked by (outward) bowing at the knee, which means that the lower leg is angled inward ( medially) in relation to the thigh's axis, giving th ...

'' (bow-leggedness), while ''coxa vara'' leads to ''

genu valgum Genu valgum, commonly called "knock-knee", is a condition in which the knees angle in and touch each other when the human leg, legs are straightened. Individuals with severe valgus deformity, valgus deformities are typically unable to touch thei ...

'' (knock-knees). Coxa-valga-norma-vara-000

Changes in the CCD angle is the result of changes in the stress patterns applied to the hip joint. Such changes, caused for example by a dislocation, change the

trabecula A trabecula (: trabeculae, from Latin for 'small beam') is a small, often microscopic, biological tissue, tissue element in the form of a small Beam (structure), beam, strut or rod that supports or anchors a framework of parts within a body or ...

r patterns inside the bones. Two continuous trabecular systems emerging on the auricular surface of the

sacroiliac joint The sacroiliac joint or SI joint (SIJ) is the joint between the sacrum and the ilium bones of the pelvis, which are connected by strong ligaments. In humans, the sacrum supports the spine and is supported in turn by an ilium on each side. The ...

meander and criss-cross each other down through the hip bone, the femoral head, neck, and shaft. * In the hip bone, one system arises on the upper part of the auricular surface to converge onto the posterior surface of the

greater sciatic notch The greater sciatic notch is a notch in the ilium, one of the bones that make up the human pelvis. It lies between the posterior inferior iliac spine (above), and the ischial spine (below). The sacrospinous ligament changes this notch into an ope ...

, from where its trabeculae are reflected to the inferior part of the acetabulum. The other system emerges on the lower part of the auricular surface, converges at the level of the

superior gluteal line The gluteal lines are three curved lines outlined from three bony ridges on the exterior surface of the ilium in the gluteal region. They are the anterior gluteal line; the inferior gluteal line, and the posterior gluteal line. The gluteus mi ...

, and is reflected laterally onto the upper part of the acetabulum. * In the femur, the first system lines up with a system arising from the lateral part of the femoral shaft to stretch to the inferior portion of the femoral neck and head. The other system lines up with a system in the femur stretching from the medial part of the femoral shaft to the superior part of the femoral head.Palastanga (2006), p 353 On the lateral side of the hip joint the

fascia lata The fascia lata is the deep fascia of the thigh. It encloses the thigh muscles and forms the outer limit of the fascial compartments of thigh, which are internally separated by the medial intermuscular septum and the lateral intermuscular sept ...

is strengthened to form the

iliotibial tract The iliotibial tract or iliotibial band (ITB; also known as Maissiat's band or the IT band) is a longitudinal fibrous reinforcement of the fascia lata. The action of the muscles associated with the ITB ( tensor fasciae latae and some fibers of g ...

which functions as a tension band and reduces the bending loads on the proximal part of the femur.

Capsule

Proximally, capsule of the hip joint is attached to the edge of the acetabulum, acetabular labrum, and transverse acetabular ligament. Distally, it is attached to the trochanters of the femur and intertrochanteric line anteriorly. Posteriorly, it is attached to a junction between medial two-thirds and lateral one-third of the femoral neck, one finger breadth away from the intertrochanteric crest. From its attachment at the femoral neck, the fibres of the capsule reflected backwards towards the acetabulum, carrying retinacula vessels supplying the femoral head. The part of femoral neck outside the capsule is shorter in front than posteriorly. The strong but loose fibrous capsule of the hip joint permits the hip joint to have the second largest range of movement (second only to the

shoulder The human shoulder is made up of three bones: the clavicle (collarbone), the scapula (shoulder blade), and the humerus (upper arm bone) as well as associated muscles, ligaments and tendons. The articulations between the bones of the shoulder m ...

) and yet support the weight of the body, arms and head. The capsule has two sets of fibers: longitudinal and circular. * The circular fibers form a collar around the femoral neck called the

zona orbicularis The zona orbicularis or annular ligament is a ligament on the neck of the femur formed by the circular fibers of the articular capsule of the hip joint In vertebrate anatomy, the hip, or coxaLatin ''coxa'' was used by Celsus in the sense "hi ...

. * The longitudinal retinacular fibers travel along the neck and carry blood vessels.

Ligaments

The hip joint is reinforced by four ligaments, of which three are extracapsular and one intracapsular. The extracapsular ligaments are the iliofemoral, ischiofemoral, and

pubofemoral ligament The pubofemoral ligament (or pubocapsular ligament) is a ligament which reinforces the inferior and anterior portions of the joint capsule of the hip joint. The ligament attaches superiorly at the superior ramus of pubis, and the iliopubic emine ...

s attached to the bones of the pelvis (the ilium,

ischium The ischium (; : is ...

, and pubis respectively). All three strengthen the capsule and prevent an excessive range of movement in the joint. Of these, the Y-shaped and twisted iliofemoral ligament is the strongest ligament in the human body. It has a tensile strength of 350 kg. Iliofemoral ligament is a thickening of the anterior capsule extending from

anterior inferior iliac spine The anterior inferior iliac spine (AIIS) is a bony eminence on the anterior border of the hip bone, or, more precisely, the wing of the ilium. Structure The AIIS is a bony eminence on the anterior border of the ilium. It is below the anterior ...

intertrochanteric line The intertrochanteric line is a line upon the anterior aspect of the proximal end of the femur, extending between the lesser trochanter and the greater trochanter. It is a rough, variable ridge. Structure The intertrochanteric line marks the bound ...

. Ischiofemoral ligament is the thickening of posterior capsule of the hip and pubofemoral ligament is the thickening of the inferior capsule. In the upright position, iliofemoral ligament prevents the trunk from falling backward without the need for muscular activity, thus preventing excessive hyperextension. In the sitting position, it becomes relaxed, thus permitting the pelvis to tilt backward into its sitting position. Ischiofemoral prevents excessive extension and the pubofemoral ligament prevents excess abduction and extension. The

, which lies like a collar around the most narrow part of the

femoral neck The femoral neck (also femur neck or neck of the femur) is a flattened pyramidal process of bone, connecting the femoral head with the femoral shaft, and forming with the latter a wide angle opening medialward. Structure The neck is flattene ...

, is covered by the other ligaments which partly radiate into it. The zona orbicularis acts like a buttonhole on the femoral head and assists in maintaining the contact in the joint. All three ligaments become taut when the joint is extended - this stabilises the joint, and reduces the energy demand of muscles when standing. The intracapsular ligament, the ligamentum teres, is attached to a depression in the acetabulum (the acetabular notch) and a depression on the femoral head (the fovea of the head). It is only stretched when the hip is dislocated, and may then prevent further displacement. It is not that important as a ligament but can often be vitally important as a conduit of a small artery to the head of the femur, that is, the . This artery is not present in everyone but can become the only blood supply to the bone in the head of the femur when the neck of the femur is fractured or disrupted by injury in childhood.''Thieme Atlas of Anatomy'' (2006), pp 383, 440

Blood supply

The hip joint is supplied with blood from the medial circumflex femoral and lateral circumflex femoral arteries, which are both usually branches of the

deep artery of the thigh The deep femoral artery also known as the deep artery of the thigh, or profunda femoris artery, is a large branch of the femoral artery. It travels more deeply ("profoundly") than the rest of the femoral artery. It gives rise to the lateral circ ...

(profunda femoris), but there are numerous variations and one or both may also arise directly from the

femoral artery The femoral artery is a large artery in the thigh and the main arterial supply to the thigh and leg. The femoral artery gives off the deep femoral artery and descends along the anteromedial part of the thigh in the femoral triangle. It enters ...

. There is also a small contribution from the foveal artery, a small vessel in the ligament of the head of the femur which is a branch of the posterior division of the obturator artery, which becomes important to avoid

avascular necrosis Avascular necrosis (AVN), also called osteonecrosis or bone infarction, is death of bone tissue due to interruption of the blood supply. Early on, there may be no symptoms. Gradually joint pain may develop, which may limit the person's abilit ...

of the head of the femur when the blood supply from the medial and lateral circumflex arteries are disrupted (e.g. through fracture of the neck of the femur along their course). The hip has two anatomically important

anastomoses An anastomosis (, : anastomoses) is a connection or opening between two things (especially cavities or passages) that are normally diverging or branching, such as between blood vessels, leaf#Veins, leaf veins, or streams. Such a connection may be ...

, the cruciate and the trochanteric anastomoses, the latter of which provides most of the blood to the head of the femur. These anastomoses exist between the femoral artery or profunda femoris and the gluteal vessels.Clemente (2006), p 227

Muscles and movements

The hip muscles act on three mutually perpendicular main axes, all of which pass through the center of the

, resulting in three

degrees of freedom In many scientific fields, the degrees of freedom of a system is the number of parameters of the system that may vary independently. For example, a point in the plane has two degrees of freedom for translation: its two coordinates; a non-infinite ...

and three pair of principal directions:

Flexion Motion, the process of movement, is described using specific anatomical terminology, anatomical terms. Motion includes movement of Organ (anatomy), organs, joints, Limb (anatomy), limbs, and specific sections of the body. The terminology used de ...

and

extension Extension, extend or extended may refer to: Mathematics Logic or set theory * Axiom of extensionality * Extensible cardinal * Extension (model theory) * Extension (proof theory) * Extension (predicate logic), the set of tuples of values that ...

around a transverse axis (left-right);

lateral rotation Motion, the process of movement, is described using specific anatomical terms. Motion includes movement of organs, joints, limbs, and specific sections of the body. The terminology used describes this motion according to its direction relativ ...

and

medial rotation Motion, the process of movement, is described using specific anatomical terminology, anatomical terms. Motion includes movement of Organ (anatomy), organs, joints, Limb (anatomy), limbs, and specific sections of the body. The terminology used de ...

around a longitudinal axis (along the thigh); and abduction and

adduction Motion, the process of movement, is described using specific anatomical terms. Motion includes movement of organs, joints, limbs, and specific sections of the body. The terminology used describes this motion according to its direction relativ ...

around a sagittal axis (forward-backward);''Thieme Atlas of Anatomy'' (2006), p 386 and a combination of these movements (i.e. circumduction, a compound movement in which the leg describes the surface of an irregular cone). Some of the hip muscles also act on either the vertebral joints or the knee joint, that with their extensive areas of origin and/or insertion, different part of individual muscles participate in very different movements, and that the range of movement varies with the position of the hip joint. Additionally, the inferior and Superior gemelli muscles assist the

obturator internus The internal obturator muscle or obturator internus muscle originates on the medial surface of the obturator membrane, the ischium near the membrane, and the rim of the pubis (bone), pubis. It exits the pelvis, pelvic cavity through the lesser sc ...

and the three muscles together form the three-headed muscle known as the triceps coxae. The movements of the hip joint is thus performed by a series of muscles which are here presented in order of importance with the range of motion from the neutral zero-degree position indicated: * Lateral or external rotation (30° with the hip extended, 50° with the hip flexed):

gluteus maximus The gluteus maximus is the main extensor muscle of the hip in humans. It is the largest and outermost of the three gluteal muscles and makes up a large part of the shape and appearance of each side of the hips. It is the single largest muscle in ...

;

quadratus femoris The quadratus femoris is a flat, quadrilateral skeletal muscle. Located on the posterior side of the hip joint, it is a strong external rotator and adductor of the thigh, but also acts to stabilize the femoral head in the acetabulum. The quad ...

;

; dorsal fibers of

gluteus medius The gluteus medius, one of the three gluteal muscles, is a broad, thick, radiating muscle. It is situated on the outer surface of the pelvis. Its posterior third is covered by the gluteus maximus, its anterior two-thirds by the gluteal aponeuros ...

and

minimus The Minimus books are a series of school textbooks, written by Barbara Bell, illustrated by Helen Forte, and published by the Cambridge University Press, designed to help children of primary school age to learn Latin. The books espouse some of th ...

;

iliopsoas The iliopsoas muscle (; ) refers to the joined psoas major and the iliacus muscles. The two muscles are separate in the abdomen, but usually merge in the thigh. They are usually given the common name ''iliopsoas''. The iliopsoas muscle joins t ...

(including

psoas major The psoas major ( or ; from ) is a long fusiform muscle located in the lateral lumbar region between the vertebral column and the brim of the lesser pelvis. It joins the iliacus muscle to form the iliopsoas. In other animals, this muscle is e ...

from the vertebral column);

obturator externus The external obturator muscle or obturator externus muscle (; OE) is a flat, triangular muscle, which covers the outer surface of the anterior wall of the pelvis. It is sometimes considered part of the medial compartment of thigh, and sometime ...

;

adductor magnus 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 ramu ...

longus Longus, sometimes Longos (), was the author of an ancient Greek novel or romance, '' Daphnis and Chloe''. Nothing is known of his life; it is assumed that he lived on the isle of Lesbos (setting for ''Daphnis and Chloe'') during the 2nd centu ...

, brevis, and

;

piriformis The piriformis muscle () is a flat, pyramidally-shaped muscle in the gluteal region of the lower limbs. It is one of the six muscles in the lateral rotator group. The piriformis muscle has its origin upon the front surface of the sacrum, and in ...

; and sartorius. The

iliofemoral ligament The iliofemoral ligament is a thick and very tough triangular capsular ligament of the hip joint situated anterior to this joint. It attaches superiorly at the inferior portion of the anterior inferior iliac spine and adjacent portion of the marg ...

inhibits lateral rotation and extension, this is why the hip can rotate laterally to a greater degree when it is flexed. * Medial or internal rotation (40°): anterior fibers of

and

;

tensor fasciae latae The tensor fasciae latae (or tensor fasciæ latæ or, formerly, tensor vaginae femoris) is a muscle of the thigh. Together with the gluteus maximus, it acts on and is continuous with the iliotibial band, which attaches to the tibia. The muscle as ...

; the part of

inserted into the

adductor tubercle Adductor may refer to: * Adductor muscle (disambiguation) * Adductor canal See also * Adduction, a motion that pulls towards the midline of the body or limb {{disambiguation {{Authority control Bones of the lower limb *Hip