(Redirected from Back)
:''"Back" redirects here. For other uses, please see
Back (disambiguation).''
The 'human back' is the large
posterior area of the
human body, rising from the top of the
buttocks to the back of the
neck and the shoulders. It is the surface opposite to the
chest, its height being defined by the
vertebral column (commonly referred to as the ''spine'' or ''backbone'') and its breadth being supported by the
ribcage and
shoulders. The
spinal canal runs through the spine and provides nerves to the rest of the body.
Anatomy of the back
Skeletal structure of the back

'Figure 3 :' Posterior view of the thorax and shoulder girdle. (Morris.)
The central feature of the human back is the
vertebral column, specifically the length from the top of the
thoracic vertebrae to the bottom of the
lumbar vertebrae, which houses the
spinal cord in its
spinal canal, and which generally has some curvature that gives shape to the back. The ribcage extends from the spine at the top of the back (with the top of the ribcage corresponding to the T1
vertebra), more than halfway down the length of the back, leaving an area with less protection between the bottom of the ribcage and the hips. The width of the back at the top is defined by the
scapula, the broad, flat bones of the shoulders.
Muscles of the back
The spine is bordered by several groups of
muscles, including the
intertransversarii muscle which facilitate movement between the individual
vertabrae, and the
multifidus spinae, which facilitate the movement of the spine as a whole.
Other muscles in the back are associated with the movement of the neck and shoulders. The
trapezius muscle, which is named from its
trapezium-like shape, runs between the
neck, the
anterior chain, the two
shoulders, and the thoracic vertebra, T12. The large
latissimus dorsi make a triangle from the shoulder to the hip. The significant mass of muscles in the back can be developed through
back exercises.
Function of the back
The intricate anatomy of the back is designed to both provide support for the head and trunk of the body, strength in the trunk of the body, as well as a great deal of flexibility and movement. The upper back has the most structural support, with the ribs attached firmly to each level of the thoracic spine and very limited movement. The lower back allows for flexibility and movement in all directions.
Back pain
Main articles: Back pain
The back comprises interconnecting nerves, bones, muscles, ligaments and tendons, all of which can be a source of pain.
Back pain is one of the most common types of pain in adults. By far the most common cause of back pain is muscle strain. The back muscles can usually heal themselves within a couple of weeks, but the pain can be intense and debilitating. Other common sources of back pain include disc problems, such as
degenerative disc disease or a
lumbar disc herniation, many types of fractures, such as
spondylolisthesis or an osteoporotic fracture, or
osteoarthritis [1].

Back of an obese male.
Organs of the back
The
lungs are within the ribcage, and extend to the back of the ribcage, making it possible for them to be listened into through the back. The
kidneys are situated beneath the muscles in the area below the end of the ribcage, loosely connected to the
peritoneum. A strike to the lower back can damage the kidneys of the person being hit.
Surface of the back
The
skin of the human back is thicker and has fewer nerve endings than the skin on any other part of the torso. With some notable exceptions (see, e.g.
George "The Animal" Steele), it tends to have less hair than the chest on men. The upper-middle back is also the one area of the body which a typical human under normal conditions might be unable to physically touch. When this area is
itchy, a backscratcher can be used to ease the discomfort.
Significance in human society

A tattoo on the lower back.
The curvature of the female back is a frequent theme in paintings, because the sensibilities of many cultures permit the back to be shown nude - implying full nudity without actually displaying it. Indeed, the practice of showing explicitness on the lower back has been performed for centuries. Certain articles of clothing, such as the
haltertop and the
backless dress, are designed to expose the back in this manner. The back also serves as the largest
canvas for
body art on the human body. Because of its size and the relative lack of hair, the back presents an ideal canvas on the human body for
Lower back tattoos. Indeed, some individuals have
tattoos that cover the entirety of the back. Others have smaller tattoos at significant locations, such as the shoulder blade or the bottom of the back.
Many
English idioms mention the back, usually highlighting it as an area of vulnerability; one must "watch one's back", or one may end up "with one's back up against the wall"; worse yet, someone may "stab one in the back", but hopefully a friend "has got one's back". The back is also a symbol of strength and hard work, with those seeking physical labor looking for "strong backs", and workers being implored to "put their back into it".
References
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Spinal anatomy and back pain