The spine is an important structure for everyday human functions. It allows us to stand upright and carries the spinal cord and nerves that help to control walking and many other important bodily functions that we take for granted.
The spine is made up of 3 main sections – cervical, thoracic, lumbar. The sacrum and coccyx sit below the lumbar spine. Each part of the spine has a slight curve that when pieced together allows the overall alignment of the spine to remain neutral. Each segment of spine is made up of individual vertebrae (bones), intervertebral discs (shock absorbers), ligaments and muscles. These all function together to protect the spinal cord and individual nerves, as well as allow for movement of the spine without having instability.
To allow for movement, a pair of facet joints sit at the back of the spine, and are oriented in a particular direction that allows for movement. Together with the intervertebral disc, supporting ligaments and muscles, these are the crucial stabilising factors of each individual spinal motion segment.
At each level of the spine a pair of nerve roots exit through their dedicated neural foramen. In the cervical spine the majority of these nerves enter the brachial plexus, and are then divided into their respective nerves to control the functions of the upper limb. In the thoracic spine these nerves mostly control sensation of the body wall. In the lumbar and sacral spine, these nerves mostly enter the lumbar plexus and then divide into their respective nerves to control the functions of the leg as well as other important bodily functions.