The human leg, in the general word sense, is the entire lower limb of the human body, including the foot, thigh and even the hip or gluteal region. However, the definition in human anatomy refers only to the section of the lower limb extending from the knee to the ankle, also known as the crus or, especially in non-technical use, the shank. Legs are used for standing, and all forms of locomotion including recreational such as dancing, and constitute a significant portion of a person's mass. Female legs generally have greater hip anteversion and tibiofemoral angles, but shorter femur and tibial lengths than those in males.
The sacrum, in human anatomy, is a large, triangular bone at the base of the spine that forms by the fusing of the sacral vertebrae (S1–S5) between ages 18 and 30.
The internal pudendal artery is one of the three pudendal arteries. It branches off the internal iliac artery, and provides blood to the external genitalia.
The piriformis muscle is a muscle in the gluteal region of the lower limbs. It is one of the six 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.
The internal iliac artery is the main artery of the pelvis.
The ischium forms the lower and back region of the hip bone.
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.
The superior gluteal artery is the largest and final branch of the internal iliac artery. It is the continuation of the posterior division of that vessel. It is a short artery which runs backward between the lumbosacral trunk and the first sacral nerve. It divides into a superficial and a deep branch after passing out of the pelvis above the upper border of the piriformis muscle.
The inferior gluteal artery, the smaller of the two terminal branches of the anterior trunk of the internal iliac artery, is distributed chiefly to the buttock and back of the thigh.
The lesser sciatic foramen is an opening between the pelvis and the back of the thigh. The foramen is formed by the sacrotuberous ligament which runs between the sacrum and the ischial tuberosity and the sacrospinous ligament which runs between the sacrum and the ischial spine.
The greater sciatic foramen is an opening in the posterior human pelvis. It is formed by the sacrotuberous and sacrospinous ligaments. The piriformis muscle passes through the foramen and occupies most of its volume. The greater sciatic foramen is wider in women than in men.
The wing of ilium is the large expanded portion which bounds the greater pelvis laterally. It presents for examination two surfaces—an external and an internal—a crest, and two borders—an anterior and a posterior.
The internal iliac vein begins near the upper part of the greater sciatic foramen, passes upward behind and slightly medial to the internal iliac artery and, at the brim of the pelvis, joins with the external iliac vein to form the common iliac vein.
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 opening, the greater sciatic foramen.
Below the ischial spine is a small notch, the lesser sciatic notch; it is smooth, coated in the recent state with cartilage, the surface of which presents two or three ridges corresponding to the subdivisions of the tendon of the Obturator internus, which winds over it.
The following outline is provided as an overview of and topical guide to human anatomy:
The hip bone is a large irregular bone, constricted in the center and expanded above and below. In some vertebrates it is composed of three major regions: the ilium, ischium, and the pubis.
The pelvis is the lower part of the trunk, between the abdomen and the thighs, together with its embedded skeleton.
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.
