The Hip Bone - Ilium - Ischium - Pubis - TeachMeAnatomy
The left and right hip bones (innominate bones, pelvic bones) are two Together , the ilium, pubis and ischium form a cup-shaped socket. Norman Edward Robinson, Kim A. Sprayberry It is well documented that young horses are predisposed to pelvic fractures: in one study, 60% of the the acetabulum: the ilium cranially, the ischium caudally, and the pubis medially. The two halves of the pelvis meet ventrally at the pubic symphysis, which is a joint that. The pelvis (plural pelves or pelvises) is either the lower part of the trunk of the human body They are attached to the sacrum posteriorly, connected to each other anteriorly, and joined with the two Each hip bone consists of 3 sections, ilium, ischium, and pubis. During puberty, they fuse together to form a single bone.
Iliopsoas flexes and externally rotates the hip joints, while unilateral contraction bends the trunk laterally and bilateral contraction raises the trunk from the supine position. Anterior view for the top-left and right diagrams. Posterior view for the bottom-left diagram, Main article: Muscles of the hip The muscles of the hip are divided into a dorsal and a ventral group.
The dorsal hip muscles are either inserted into the region of the lesser trochanter anterior or inner group or the greater trochanter posterior or outer group. Anteriorly, the psoas major and occasionally psoas minor originates along the spine between the rib cage and pelvis. The iliacus originates on the iliac fossa to join psoas at the iliopubic eminence to form the iliopsoas which is inserted into the lesser trochanter.
Maximus has a wide origin stretching from the posterior part of the iliac crest and along the sacrum and coccyx, and has two separate insertions: It is primarily an extensor and lateral rotator of the hip joint, but, because of its bipartite insertion, it can both adduct and abduct the hip.
Medius and minimus arise on the external surface of the ilium and are both inserted into the greater trochanter. Their anterior fibers are medial rotators and flexors while the posterior fibers are lateral rotators and extensors.
The piriformis has its origin on the ventral side of the sacrum and is inserted on the greater trochanter. It abducts and laterally rotates the hip in the upright posture and assists in extension of the thigh. The internal and external obturator muscles together with the quadratus femoris are lateral rotators of the hip.
Together they are stronger than the medial rotators and therefore the feet point outward in the normal position to achieve a better support.
The obturators have their origins on either sides of the obturator foramen and are inserted into the trochanteric fossa on the femur. Quadratus arises on the ischial tuberosity and is inserted into the intertrochanteric crest.
Pelvis - Wikipedia
The superior and inferior gemelliarising from the ischial spine and ischial tuberosity respectively, can be thought of as marginal heads of the obturator internus, and their main function is to assist this muscle. The extensors and flexors act on the knee joint, while the adductors mainly act on the hip joint.
The thigh adductors have their origins on the inferior ramus of the pubic bone and are, with the exception of gracilisinserted along the femoral shaft. Together with sartorius and semitendinosusgracilis reaches beyond the knee to their common insertion on the tibia. Three of the four muscles have their origins on the femur, while rectus femoris arises from the anterior inferior iliac spine and is thus the only of the four acting on two joints.
The semitendinosus and semimembranosus are inserted on the tibia on the medial side of the knee, while biceps femoris is inserted on the fibulaon the knee's lateral side. During childbirth unless by Cesarean section the fetus passes through the maternal pelvic opening. There are also different types of pelvic fracture often resulting from traffic accidents.
Pelvic pain generally, can affect anybody and has a variety of causes; endometriosis in women, bowel adhesionsirritable bowel syndromeand interstitial cystitis. There are many anatomical variations of the pelvis. In the female the pelvis can be of a much larger size than normal, known as a giant pelvis or pelvis justo majoror it can be much smaller, known as a reduced pelvis or pelvis justo minor.
Caldwell—Moloy classification[ edit ] Throughout the 20th century pelvimetric measurements were made on pregnant women to determine whether a natural birth would be possible, a practice today limited to cases where a specific problem is suspected or following a caesarean delivery. William Edgar Caldwell and Howard Carmen Moloy studied collections of skeletal pelves and thousands of stereoscopic radiograms and finally recognized three types of female pelves plus the masculine type.
In and they published their typology, including the Greek names since then frequently quoted in various handbooks: Gynaecoid gyne, womananthropoid anthropos, human beingplatypelloid platys, flatand android aner, man.
Hip Bone Anatomy or Pelvic Bone[Ilium-Pubis-Ischium]
Its inlet is either slightly oval, with a greater transverse diameter, or round. The interior walls are straight, the subpubic arch wide, the sacrum shows an average to backward inclination, and the greater sciatic notch is well rounded.
Because this type is spacious and well proportioned there is little or no difficulty in the birth process. Caldwell and his co-workers found gynaecoid pelves in about 50 per cent of specimens.
The platypelloid pelvis has a transversally wide, flattened shape, is wide anteriorly, greater sciatic notches of male type, and has a short sacrum that curves inwards reducing the diameters of the lower pelvis. Ilium When you place your hands on your waist, you can feel the arching, superior margin of the ilium along your waistline see Figure 8.
Hip Bone Anatomy or Pelvic Bone[Ilium-Pubis-Ischium] | Bone and Spine
This curved, superior margin of the ilium is the iliac crest. The rounded, anterior termination of the iliac crest is the anterior superior iliac spine. This important bony landmark can be felt at your anterolateral hip.
Inferior to the anterior superior iliac spine is a rounded protuberance called the anterior inferior iliac spine. Both of these iliac spines serve as attachment points for muscles of the thigh. Posteriorly, the iliac crest curves downward to terminate as the posterior superior iliac spine.
More inferiorly is the posterior inferior iliac spine.
This is located at the inferior end of a large, roughened area called the auricular surface of the ilium. The auricular surface articulates with the auricular surface of the sacrum to form the sacroiliac joint.
Both the posterior superior and posterior inferior iliac spines serve as attachment points for the muscles and very strong ligaments that support the sacroiliac joint. The shallow depression located on the anteromedial internal surface of the upper ilium is called the iliac fossa. The inferior margin of this space is formed by the arcuate line of the ilium, the ridge formed by the pronounced change in curvature between the upper and lower portions of the ilium.
The large, inverted U-shaped indentation located on the posterior margin of the lower ilium is called the greater sciatic notch. Ischium The ischium forms the posterolateral portion of the hip bone see Figure 8. The large, roughened area of the inferior ischium is the ischial tuberosity. This serves as the attachment for the posterior thigh muscles and also carries the weight of the body when sitting.
You can feel the ischial tuberosity if you wiggle your pelvis against the seat of a chair. Projecting superiorly and anteriorly from the ischial tuberosity is a narrow segment of bone called the ischial ramus.
The slightly curved posterior margin of the ischium above the ischial tuberosity is the lesser sciatic notch. The bony projection separating the lesser sciatic notch and greater sciatic notch is the ischial spine. The central body of the ischium connects the ischial tuberosity, the acetabulum and the ischial spine. Pubis The pubis forms the anterior portion of the hip bone see Figure 8. The enlarged medial portion of the pubis is the pubic body. Located superiorly on the pubic body is a small bump called the pubic tubercle.
The superior pubic ramus is the segment of bone that passes laterally from the pubic body to join the ilium. The narrow ridge running along the superior margin of the superior pubic ramus is the pectineal line of the pubis. The pubic body is joined to the pubic body of the opposite hip bone by the pubic symphysis.
Extending downward and laterally from the body is the inferior pubic ramus. The pubic arch is the bony structure formed by the pubic symphysis, and the bodies and inferior pubic rami of the adjacent pubic bones. The inferior pubic ramus extends downward to join the ischial ramus. Together, these form the single ischiopubic ramus, which extends from the pubic body to the ischial tuberosity. The transversus abdominis muscle attaches to the pubic crest and pecten pubis via a conjoint tendon Back muscles The multifidus muscle in the sacral region attaches to the medial surface of posterior superior iliac spinethe posterior sacroiliac ligaments and several places to the sacrum.
Gluteal muscles The gluteus maximus muscle arises from the posterior gluteal line of the inner upper ilium, and the rough portion of bone including the iliac crest, the fascia covering the gluteus medius gluteal aponeurosisas well as the sacrum, coccyx, the erector spinae lumbodorsal fasciathe sacrotuberous ligament.
The gluteus medius muscle: The gluteus medius also originates from the gluteal aponeurosis that covers its outer surface. Gluteus minimus muscle originates between the anterior and inferior gluteal linesand from the margin of the greater sciatic notch. Lateral rotator group The piriformis muscle originates from the superior margin of the greater sciatic notch as well as the sacroiliac joint capsule and the sacrotuberous ligament and part of the spine and sacrum.
The superior gemellus muscle arises from the outer surface of the ischial spine The obturator internus muscle arises from the inner surface of the antero-lateral wall of the hip bone, where it surrounds the greater part of the obturator foramenbeing attached to the inferior rami of the pubis and ischium, and at the side to the inner surface of the hip bone below and behind the pelvic brimreaching from the upper part of the greater sciatic foramen above and behind to the obturator foramen below and in front.
It also arises from the pelvic surface of the obturator membrane except in the posterior part, from the tendinous archand to a slight extent from the obturator fasciawhich covers the muscle.