The back (from Latin backsum) is the posterior face of the human body located between the shoulders and the buttocks.

Structure. The back has a complex structure (1) consisting of:

• the spine in its center, itself made up of 32 to 34 bones called vertebrae,
• intervertebral discs positioned between the vertebrae,
• ligaments connecting the vertebrae to each other,
• the posterior part of the ribs, partly attached to the spine,
• many muscles, including the deep muscles connecting the vertebrae to each other and the superficial muscles,
• tendons connecting muscles to bones,
• blood and lymphatic vessels,
• of the spinal cord, part of the central nervous system, located in the spine. (1)

Support and protection role. The spine gives the back a role of supporting the head and protecting the spinal cord.

Role in mobility and posture. All the components of the back make it possible to preserve the posture of the trunk and thus maintain the standing position. The structure of the back allows many movements such as torsion movements of the trunk, bending of the trunk or even traction.

Back pain. It is defined as a localized pain that begins most often in the spine and generally affects the muscle groups around it. Depending on their origin, three main forms are distinguished: neck pain, back pain and back pain. Sciatica, characterized by pain starting in the lower back and extending into the leg. They are common and are due to compression of the sciatic nerve. Different pathologies can be at the origin of this pain. (2)

• Degenerative pathologies. Different pathologies can lead to the progressive degradation of cellular elements. Osteoarthritis is characterized by wear of the cartilage protecting the bones of the joints. (3) The herniated disc corresponds to the expulsion behind the nucleus of the intervertebral disc, by wear of the latter. This can result in compression of the spinal cord or sciatic nerve.
• Deformation of the spine. Different deformations of the column can appear. Scoliosis is a lateral displacement of the column (4). Kyphosis develops with an excessive curvature of the back at shoulder height while lordosis is associated with an accentuated arch in the lower back. (4)
• Lumbago and stiff neck. These pathologies are due to deformations or tears in the ligaments or muscles, located respectively in the lumbar region or in the cervical region.

Drug treatments. Depending on the pathology, certain drugs may be prescribed, including painkillers.

Physiotherapy. Back rehabilitation can be carried out with physiotherapy or osteopathy sessions.

Surgical treatment. Depending on the pathology, a surgical intervention may be performed on the back.

Physical examination. The doctor’s observation of the back posture is the first step in identifying an abnormality.

Radiological examinations. Depending on the suspected or proven pathology, additional examinations may be performed such as an X-ray, an ultrasound, a CT scan, an MRI or a scintigraphy.

Published in the scientific journal Stem Cell, researchers from an Inserm unit have succeeded in transforming adipose stem cells into cells that can replace intervertebral discs. This work aims to renew the worn intervertebral discs, causing some of the lower back pain. (5)