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.

Skeletal structure of the back

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.

Function of the back

The intricate anatomy of the back provides 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 (lumbar vertabrae) allows for flexibility and movement in back bending (extension) and forward bending (flexion). It does not permit twisting.

Back pain

main: 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.

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.