BACK

The back supports the weight of the body, allowing for flexible movement while protecting vital organs and nerve structures. The back comprises the spine and spinal nerves, as well as several different muscle groups.

 

Back pain is one of the most common reasons people go to the doctor or miss work, and it is a leading cause of disability worldwide. Most people have back pain at least once.

The causes of back pain are numerous; some are self-inflicted due to a lifetime of bad habits. Other back pain causes include accidents, muscle strains, and sports injuries. Although the causes may be different, most often they share the same symptoms.

Symptoms of back pain can include:

 

  • Persistent aching or stiffness anywhere along your spine, from the base of the neck to the tail bone

  • Sharp, localised pain in the neck, upper back, or lower back especially after lifting heavy objects or engaging in other strenuous activity; (pain in the upper back can also be a sign of a heart attack or other life-threatening conditions.)

  • Chronic ache in the middle or lower back, especially after sitting or standing for extended periods

  • Back pain that radiates from the low back to the buttock, down the back of the thigh, and into the calf and toes

  • Inability to stand straight without having pain or muscle spasms in the lower back

The muscles of the back can be divided into three groups – superficial, intermediate and deep:

  • Superficial – associated with movements of the shoulder.

  • Intermediate – associated with movements of the thoracic cage.

  • Deep – associated with movements of the vertebral column.

The superficial back muscles are situated underneath the skin and superficial fascia. They originate from the vertebral column and attach to the bones of the shoulder – the clavicle, scapula and humerus. All these muscles are therefore associated with movements of the upper limb. The muscles in this group are the trapezius, latissimus dorsi, levator scapulae and the rhomboids. The trapezius and the latissimus dorsi lie the most superficially, with the trapezius covering the rhomboids and levator scapulae.

The intermediate group contains two muscles – the serratus posterior superior and serratus posterior inferior. These muscles run from the vertebral column to the ribcage, and assist with elevating and depressing the ribs. They are thought to have a slight respiratory function.

The deep muscles of the back are well-developed, and collectively extend from the sacrum to the base of the skull. They are associated with the movements of the vertebral column, and the control of posture.

The two main ligaments in the back are the anterior longitudinal ligament and the posterior longitudinal ligament. These two ligaments connect and support the spine from the neck to the lower back.

The spine is composed of 33 bones called vertebrae, which stack together to form the spinal canal. This protects the spinal cord inside.The spinal cord is a tubular bundle of nervous tissue and supporting cells that extends from the brainstem to the lumbar vertebrae. Together, the spinal cord and the brain form the central nervous system.

The spine consists of five sections. From the top of the spine to the bottom, these sections are:

  • The cervical spine: The cervical spine is the top part of the spine. It runs from the neck to the upper back. It consists of seven vertebrae. The cervical spine protects the nerves connecting to the brain, allowing the head to move freely while supporting its weight.

  • The thoracic spine: The thoracic spine is the middle part of the spine, connecting the cervical and lumbar spine. It has 12 vertebrae. The thoracic spine helps keep the body upright and stable.

  • The lumbar spine: The lumbar spine is the lower part of the back. It is made up of five larger vertebrae. These support most of the body’s weight.

  • The sacrum: The sacrum is the bottom part of the spine, which connects to the hip bones. The sacrum has five vertebrae fused together.

  • The coccyx: The coccyx is the base, or tailbone, of the spine. This consists of four vertebrae fused together. It joins to ligaments and muscles around the pelvis.