The thoracic portion of the spine the longest part of the spine and is made up of twelve vertebrae (T1-T12), which lies between the cervical spine (C1-C7) and the lumbar spine (L1-L5). The thoracic spine protects the very important spinal cord that begins in the brain and runs down to approximately T12 where the cord turns into what looks like a horse’s tail (the cauda equina). The spinal nerves then travel into the lumbar spine and sacrum (tailbone) and innervate the low back, pelvis, legs, and feet. Nerve roots exit at each vertebral level of the spine innervating the upper (cervical), middle (thoracic) and lower (lumbar) portions of the body.
Looking closer at the T1-T12 nerves, T1-T2 nerves innervate (motor/muscle and sensory/feeling) the top of the chest and the inner arms and hands (providing strength to the deep, intrinsic hand muscles). Nerves T3-T5 innervate the chest wall and help control the rib cage, lungs, and diaphragm (the breathing muscle that separates the chest cavity from the abdominal cavity). The T6-T12 nerves innervates the abdominal and back muscles that work with the lumbar nerves to help stabilize our core, balance, posture, and the coughing process.
The thoracic spine also supports the rib cage, which protects our lungs, heart, and its great vessels that supply our body with fresh, oxygenated (arterial) blood and trades off carbon dioxide (venous blood) for oxygen in the lungs each time we take a breath. All of this is done automatically, without effort or thinking, thanks to our autonomic nervous system (ANS— made up of sympathetic and parasympathetic nerves) of which many of the sympathetic nerves arise in the thoracic region!
Unlike the cervical and lumbar portions of the spine, which allow for a great deal of movement, the thoracic spine is much more rigid and stable, which leads to a lower risk for injury. Potential causes of mid-back pain include poor posture; prolonged sitting; or conditions like scoliosis (curvature) or hyper-kyphosis (increased “humping” of the TS); sprain of the ligaments that hold bones firmly together (usually by a sudden, unexpected movements or trauma); bruising, cracking, or fracturing of the ribs or thoracic vertebrae; compression fracturing due to osteoporosis; and overuse injuries from repetitive lifting, bending, and twisting.
Doctors of chiropractic are trained to evaluate and treat patients with MBP utilizing various forms of manual therapies (including spinal manipulation, mobilization, and massage), exercise training, posture retraining, and more.