LOWER BACK PAIN
Pain felt down the back and outer side of the thigh, leg and foot. It is usually caused by degeneration of an invertebral disc, which protrudes laterally to compress a lower lumbar or an upper sacral spinal nerve root.

The onset may be sudden, brought on by an awkward lifting or twisting movement. The back is stiff and painful. There may be numbness and weakness in the leg.

SCIATIC NERVE
The major nerve of the leg with the largest diameter. It runs down behind the thigh from the lower end of the spine. Above the knee joint it divides into two main branches, the tibial and common peroneal nerves, which are distributed to the muscles and skin of the lower leg.

ABDOMEN
The part of the body cavity below the chest. The abdomen contains the organs of digestion and excretion. In women it also contains the uterus and ovaries.

BACKBONE (SPINAL COLUMN. SPINE. VERTEBRAL COLUMN)
The flexible bony column extending from the base of the skull to the small of the back. It encloses and protects the spinal cord. It provides attachment for the muscles of the back. It is made up of individual bones (vertebra) connected by discs of fibrocartilage, and bound together by ligaments.

The adult backbone consists of 7 cervical (neck), 12 thoracic (chest), 5 lumbar (lower back), 1 sacral (hip or sacrum) and 1 coccygeal (tail or coccyx) bones.

LESION
An area of tissue with impaired function as a result of damage by disease or wounding. Secondary lesions such as crusts or scars can also be derived from primary lesions.

LIGAMENTS
Tough band of white fibrous connective tissue, that links two bones together at a joint. Ligaments are inelastic but flexible. They both strengthen the joint and limit its movements to certain directions.

LUMBAR VERTEBRAE
The 5 bones of the backbone that are situated between the thoracic vertebrae and the sacrum in the lower part of the back. They have stout processes for attachment of the strong muscles of the lower back.

LUMBOSACRAL
Relating to part of the spine composed of the lumbar vertebrae and the sacrum.

MUSCLES
Tissue, whose cells have the ability to contract, producing movement or force. Muscles possess mechanisms for converting energy derived from chemical reactions into mechanical energy.

The major functions of muscles are to produce movements of the body, to maintain the position of the body against the force of gravity, to produce movements of structures within the body and to alter pressures or tensions of structures within the body.

There are three types of muscle. Striated muscle, attached to the skeleton. Smooth muscle, found in tissues such as the stomach, and cardiac muscle which forms the wall of the heart.

PROLAPSE
The downward displacement of an organ or tissue. Usually the result of the weakening of the supporting tissues.

SPINAL CORD
The portion of the central nervous system enclosed in the vertebral column, consisting of nerve cells and bundles of nerves connecting all parts of the body with the brain.

STENOSIS
The abnormal narrowing of a passage or opening.