Ischial tuberosity

Last updated

Ischial tuberosity
Gray343.png
Capsule of hip-joint (distended). Posterior aspect. (Ischial tuberosity visible at bottom left.)
Details
Identifiers
Latin tuber ischiadicum, tuberositas ischiadica
TA98 A02.5.01.204
TA2 1342
FMA 17010
Anatomical terms of bone

The ischial tuberosity (or tuberosity of the ischium, tuber ischiadicum), also known colloquially as the sit bones or sitz bones, [1] or as a pair the sitting bones, [2] is a large posterior bony protruberance on the superior ramus of the ischium. It marks the lateral boundary of the pelvic outlet.

Contents

When sitting, the weight is frequently placed upon the ischial tuberosity. [3] The gluteus maximus provides cover in the upright posture, but leaves it free in the seated position. [4] The distance between a cyclist's ischial tuberosities is one of the factors in the choice of a bicycle saddle.

Divisions

The tuberosity is divided into two portions: a lower, rough, somewhat triangular part, and an upper, smooth, quadrilateral portion.

Additional images

See also

Notes

  1. M.D, John R. Schultz (October 28, 2019). "Sit Bones Pain (aka Sitz Bone)". Centeno-Schultz Clinic. Retrieved April 12, 2020.
  2. Sills, Franklyn (2004). Craniosacral Biodynamics: The Primal Midline and the Organization of the Body (revised, illustrated ed.). Berkeley, CA: North Atlantic Books. p. 99. ISBN   1-55643-390-5.
  3. Goossens (2005), pp 895–982
  4. Platzer (2004), p 236

Related Research Articles

<span class="mw-page-title-main">Human leg</span> Lower extremity or limb of the human body (foot, lower leg, thigh and hip)

The leg is the entire lower limb of the human body, including the foot, thigh or sometimes even the hip or buttock region. The major bones of the leg are the femur, tibia, and adjacent fibula. The thigh is between the hip and knee, while the calf (rear) and shin (front) are between the knee and foot.

<span class="mw-page-title-main">Levator ani</span> Broad, thin muscle group, situated on either side of the pelvis

The levator ani is a broad, thin muscle group, situated on either side of the pelvis. It is formed from three muscle components: the pubococcygeus, the iliococcygeus, and the puborectalis.

<span class="mw-page-title-main">Radius (bone)</span> One of the two long bones of the forearm

The radius or radial bone is one of the two large bones of the forearm, the other being the ulna. It extends from the lateral side of the elbow to the thumb side of the wrist and runs parallel to the ulna. The ulna is longer than the radius, but the radius is thicker. The radius is a long bone, prism-shaped and slightly curved longitudinally.

<span class="mw-page-title-main">Gluteus maximus</span> Largest and most superficial of the three gluteal muscles

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 the human body. Its thick fleshy mass, in a quadrilateral shape, forms the prominence of the buttocks. The other gluteal muscles are the medius and minimus, and sometimes informally these are collectively referred to as the glutes.

<span class="mw-page-title-main">Obturator internus muscle</span> One of six small hip muscles in the lateral rotator group

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.

<span class="mw-page-title-main">Hip</span> Anatomical region between the torso and the legs, holding the buttocks and genital region

In vertebrate anatomy, the hip, or coxa(pl.: coxae) in medical terminology, refers to either an anatomical region or a joint on the outer (lateral) side of the pelvis.

The biceps femoris is a muscle of the thigh located to the posterior, or back. As its name implies, it consists of two heads; the long head is considered part of the hamstring muscle group, while the short head is sometimes excluded from this characterization, as it only causes knee flexion and is activated by a separate nerve.

<span class="mw-page-title-main">Iliacus muscle</span> Flat, triangular muscle which fills the iliac fossa

The iliacus is a flat, triangular muscle which fills the iliac fossa. It forms the lateral portion of iliopsoas, providing flexion of the thigh and lower limb at the acetabulofemoral joint.

<span class="mw-page-title-main">External obturator muscle</span> One of six small hip muscles in the lateral rotator group

The external obturator muscle, obturator externus muscle is a flat, triangular muscle, which covers the outer surface of the anterior wall of the pelvis.

<span class="mw-page-title-main">Quadratus femoris muscle</span> One of six small hip muscles in the lateral rotator group

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 quadratus femoris is used in Meyer's muscle pedicle grafting to prevent avascular necrosis of femur head.

<span class="mw-page-title-main">Adductor magnus muscle</span> Muscle in the thigh

The adductor magnus is a large triangular muscle, situated on the medial side of the thigh.

The semimembranosus muscle is the most medial of the three hamstring muscles in the thigh. It is so named because it has a flat tendon of origin. It lies posteromedially in the thigh, deep to the semitendinosus muscle. It extends the hip joint and flexes the knee joint.

<span class="mw-page-title-main">Gluteal muscles</span> Group of three muscles which make up the buttocks

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, gluteus medius and gluteus minimus. The three muscles originate from the ilium and sacrum and insert on the femur. The functions of the muscles include extension, abduction, external rotation, and internal rotation of the hip joint.

<span class="mw-page-title-main">Ischium</span> Lower and back region of the hip bone

The ischium forms the lower and back region of the hip bone.

<span class="mw-page-title-main">Pubis (bone)</span> Most forward-facing of the three main regions making up the os coxa

In vertebrates, the pubis or pubic bone forms the lower and anterior part of each side of the hip bone. The pubis is the most forward-facing of the three bones that make up the hip bone. The left and right pubic bones are each made up of three sections, a superior ramus, inferior ramus, and a body.

<span class="mw-page-title-main">Sacrotuberous ligament</span>

The sacrotuberous ligament is situated at the lower and back part of the pelvis. It is flat, and triangular in form; narrower in the middle than at the ends.

<span class="mw-page-title-main">Sacrospinous ligament</span>

The sacrospinous ligament is a thin, triangular ligament in the human pelvis. The base of the ligament is attached to the outer edge of the sacrum and coccyx, and the tip of the ligament attaches to the spine of the ischium, a bony protuberance on the human pelvis. Its fibres are intermingled with the sacrotuberous ligament.

<span class="mw-page-title-main">Pelvic outlet</span>

The lower circumference of the lesser pelvis is very irregular; the space enclosed by it is named the inferior aperture or pelvic outlet. It is an important component of pelvimetry.

<span class="mw-page-title-main">Hip bone</span> Bone of the pelvis

The hip bone is a large flat bone, constricted in the center and expanded above and below. In some vertebrates it is composed of three parts: the ilium, ischium, and the pubis.

<span class="mw-page-title-main">Pelvis</span> Lower torso of the human body

The pelvis is the lower part of the trunk, between the abdomen and the thighs, together with its embedded skeleton.

References

PD-icon.svgThis article incorporates text in the public domain from page 235 of the 20th edition of Gray's Anatomy (1918)