The human leg, in the general word sense, is the entire lower limb of the human body, including the foot, thigh or sometimes 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.
A spinal nerve is a mixed nerve, which carries motor, sensory, and autonomic signals between the spinal cord and the body. In the human body there are 31 pairs of spinal nerves, one on each side of the vertebral column. These are grouped into the corresponding cervical, thoracic, lumbar, sacral and coccygeal regions of the spine. There are eight pairs of cervical nerves, twelve pairs of thoracic nerves, five pairs of lumbar nerves, five pairs of sacral nerves, and one pair of coccygeal nerves. The spinal nerves are part of the peripheral nervous system.
Lordosis is historically defined as an abnormal inward curvature of the lumbar spine. However, the terms lordosis and lordotic are also used to refer to the normal inward curvature of the lumbar and cervical regions of the human spine. Similarly, kyphosis historically refers to abnormal convex curvature of the spine. The normal outward (convex) curvature in the thoracic and sacral regions is also termed kyphosis or kyphotic. The term comes from the Greek lordōsis, from lordos.
In vertebrate anatomy, hip refers to either an anatomical region or a joint.
The psoas major 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 animals, this muscle is equivalent to the tenderloin.
The abdomen is the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the front part of the abdominal segment of the torso. The area occupied by the abdomen is called the abdominal cavity. In arthropods it is the posterior tagma of the body; it follows the thorax or cephalothorax.
In human anatomy, the muscles of the hip joint are those muscles that cause movement in the hip. Most modern anatomists define 17 of these muscles, although some additional muscles may sometimes be considered. These are often divided into four groups according to their orientation around the hip joint: the gluteal group; the lateral rotator group; the adductor group; and the iliopsoas group.
The lumbar plexus is a web of nerves in the lumbar region of the body which forms part of the larger lumbosacral plexus. It is formed by the divisions of the first four lumbar nerves (L1-L4) and from contributions of the subcostal nerve (T12), which is the last thoracic nerve. Additionally, the ventral rami of the fourth lumbar nerve pass communicating branches, the lumbosacral trunk, to the sacral plexus. The nerves of the lumbar plexus pass in front of the hip joint and mainly support the anterior part of the thigh.
The lumbar nerves are the five pairs of spinal nerves emerging from the lumbar vertebrae. They are divided into posterior and anterior divisions.
The erector spinae or spinal erectors is a set of muscles that straighten and rotate the back. The spinal erectors work together with the glutes to maintain stable posture standing or sitting.
The thoracolumbar fascia is a deep investing membrane throughout most of the posterior thorax and abdomen although it is a thin fibrous lamina in the thoracic region. Above, it is continuous with a similar investing layer on the back of the neck—the nuchal fascia.
The lumbar arteries are arteries located in the lower back or lumbar region. The lumbar arteries are in parallel with the intercostals.
The crest of the ilium is the superior border of the wing of ilium and the superiolateral margin of the greater pelvis.
The iliolumbar ligament is a strong ligament passing from the tip of the transverse process of the fifth lumbar vertebra to the posterior part of the inner lip of the iliac crest.
The lumbar fascia is an anatomic structure of the lumbar region. It consists of a band or sheet of connective tissue fibres, primarily collagen, that attaches, stabilizes, encloses and separates muscles not limited to the lumbar region as the name suggests, but extending upwards over the thorax to the neck and downwards over the muscles covering the sacrum. The upper thoracic portion is thin while the lumbar and sacral regions are thicker and stronger.
The following outline is provided as an overview of and topical guide to human anatomy:
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.
The pelvis is the lower part of the trunk, between the abdomen and the thighs, together with its embedded skeleton.
