Learn About the Spine

Understanding spine anatomy can be helpful in determining the possible source of your symptoms & educating yourself so that you can have more informed conversations with your doctors. Read on to learn about the spine & common back pain causes

About the Spine

The human spine is divided into 4 distinct sections of bones known as “vertebrae”. At the top of the spinal column, the cervical spine anatomy (or neck anatomy) is made up of 7 vertebrae. Just below with 12 vertebrae, the thoracic spine anatomy comprises the mid-torso section of the human body. Below that is the lumbar spine anatomy with 5 vertebrae. Finally, at the very bottom of the spinal column—in the area of the hips—is the sacrum, the triangular-shaped portion made up of 5 fused bones.

All voluntary movement in your body is controlled by the brain, whose main communication pathway to the muscles is a large bundle of nerves collectively known as the spinal cord. Protection for this critical pathway is provided by the bones of the spinal column.

These bones, or vertebral bodies, have a number of important functions—one is to encircle and guard the spinal cord against trauma and another is to provide the skeletal support we need to walk upright.

The Cervical Spine

( The Neck )

The Thoracic Spine

( Mid-Torso )

The Lumbar Spine

( Lower Back )

The Sacrum

( The Pelvis )

human spine

Your Spinal Discs

spinal foramen Between each pair of vertebrae is a spinal disc that acts like a shock absorber and provides flexibility during your daily activities.

The combination of the spinal disc and the attached vertebral bodies is called a spinal segment or level. At each spinal segment, nerves branch from the spinal cord and pass through openings between the vertebrae called foramen. These nerves travel to the arms and legs to control movement and relay sensation back to the brain.

spinal anatomy

Spine Pain

Degenerative Disc Disease, or "DDD", Isn't a Disease At All

Your spinal discs act as a cushion to absorb shock between the vertebrae during movement. As a result of aging or injury, sometimes the spinal disc loses its cushioning effect which may result in a loss of disc height. This loss of disc height reduces the distance between the vertebral bodies and may cause irritation or pinching of the nerves. The spinal disc may also bulge or herniate, where the disc material contained within the intervertebral disc is pushed into the spinal canal. This may cause inflammation and pressure on the local nerve.

The loss of disc height and / or bulge of the disc may result in the following symptoms.

  • Pain or discomfort in the neck or back
  • Tingling or loss of feeling in arms or legs
  • Shooting pain or discomfort in one or both legs
  • Discomfort that worsens upon standing or activity

healthy and degenerated disc

Spondylolisthesis, or "Spondy" for Short

Spondylolisthesis is a condition usually caused by a sports related injury. Genetics may play a role in the likelihood of a spondy occurring in a person that plays football, gymnastics, or a similar sport. A spondy usually occurs in the lumbar spine or low back and is described as one bone or vertebra slipping or sliding forward over the vertebra below it. This forward or anterior position may lead to the spinal cord or a nerve being compressed or squeezed.

Sometimes when a vertebra slips out of place, there maybe no symptoms or a delay in the onset of symptoms. Patients with a spondy may experience the following symptoms:

  • Pain in the low back or buttock area
  • Pain may increase with coughing or sneezing
  • Weakness, numbness or pain in one or both legs
  • Hamstrings may feel tight
  • Leg muscles may feel tight or weak
  • Patients may limp or waddle
  • Posture may change and the patient may lean forward
  • Trying to stand maybe painful or difficult to achieve
  • Loss of bladder or bowel control may occur

vertebral slip

Spinal Curvatures: Lordosis, Kyphosis, and Scoliosis

The human spine normally curves to aid in stability or balance and to assist in absorbing shock during movement. These gentle curves can be seen from the side or lateral view of the spine. When viewed from the back, the spine should run straight down the middle of the back.

When there are abnormalities or changes in the natural spinal curvature, these abnormalities are named with the following conditions and include the following symptoms.



Some lordosis is normal in the lower portion or, lumbar section, of the human spine. A decreased or exaggerated amount of lordosis that is causing spinal instability is a condition that may affect some patients.

Symptoms of Lordosis include:

  • Appearance of sway back where the lower back region has a pronounced curve and looks hollow with a pronounced buttock area
  • Difficulty with movement in certain directions
  • Low back pain


This condition is diagnosed when the patient has a rounded upper back and the spine is bent over or curved more than 50 degrees.

Symptoms of Kyphosis include:

  • Curved or hunched upper back
  • Patient’s head that leans forward
  • May have upper back pain
  • Experiences upper back discomfort after movement or exercise


The most common of the three curvatures. This condition is diagnosed when the spine looks like a “s” or “c” from the back. The spine is not straight up and down but has a curve or two running side-to-side.

Symptoms of Scoliosis include:

  • Uneven shoulders or shoulder blades causing one to sit higher than the other
  • Uneven rib cage or hips causing one to sit higher than the other
  • Misaligned head or neck that may not be centered over the spine
  • Patient’s body may lean to one side
  • May experience back pain

Spinal Instability

Spinal instability is described as the abnormal sliding or hypermobility of the bones or vertebrae of the spine. This sliding may occur during flexion (bending forward), lifting or extension (bending backward). When a disc is injured or degenerates it may lose tension or its tight grip on the vertebrae above and below it. This loss of tension allows the bones to shift or slide in abnormal directions which may irritate or pinch a nerve.

Spinal instability may not immediately cause symptoms or the onset of symptoms may occur over time. Spinal instability may be associated with the following symptoms.

  • Stabbing neck or back pain when a person stands up
  • Patient’s neck or back may lock up or get stuck during movement
  • Neck or back muscles spasm
  • Weakness or numbness in the arms or legs

spinal instability

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