Anatomy of Spinal Stenosis


Spinal stenosis is a disorder which results in persistent pain in the lower back and lower extremities. Difficulty in walking and decreased sensation in the lower extremities may also be seen in people suffering from this condition. Learn more about the anatomy of the spine below:

Bony Structures

The bony spine is naturally positioned so that individual vertebrae provide a flexible support structure while also protecting the spinal cord.

Vertebral Discs

The numerous discs have been created to be soft as well as be strong enough to provide necessary support. Also, they have a tendency to herniate backward through the outer disc segment and ligaments. This can cause irritation to the spinal cord and adjacent nerves.

Spinal Ligaments and Muscles

The nerves happen to attached to the spinal cord and then exit the spine to innervate the person's skin, muscles, and other surrounding structures that make up the back and lower extremities. These muscles and ligaments also have a tendency to become strained or irritated during activities that involve strenuous lifting and even excessive exercise.


In spinal stenosis, the exhibited symptoms are due to the complications that arise from the narrowing of the spinal canal. This sort of constriction also produces symptoms that involve impingement on the spinal cord, even the spinal vasculature, and the surrounding peripheral nerves.

Also, disc bulging and herniation along with arthritic changes of the vertebrae can cause narrowing of the spinal canal. The accompanying pain and decreased mobility that is produced due to such a condition have a chance to cause disability that can lead to a significant impairment of a patient's lifestyle.

Another common complication of chronic pain that arises due to spinal stenosis happens to be central sensitization. This can be defined as a condition involving both the peripheral nervous system (PNS) and the central nervous system of a patient (CNS).

Also, local tissue injury and inflammation play a role in activating PNS. This then sends signals through the spinal cord directly to the brain. In simple words, central sensitization is the condition that occurs when there is an increase in the overall excitability of a person's neurons present within the CNS.

This can be at the level of their spinal cord and even higher. Eventually, the normal inputs from the PNS are able to produce abnormal responses in the person. Also, low-threshold sensory fibers activated by a light touch of the patient's skin tend to activate neurons in the spinal cord. Take note that low-threshold sensory fibers normally only respond to painful stimuli. As a result, an input that would normally produce a harmless sensation will now produce significant pain.


Coming to its diagnosis, a physician performs physical examinations analyzing the tenderness or sensitivity present in certain areas of the patient's spine as well as assessing the various limitations in movement of the lower extremities.

A physician will most likely order radiological imaging, such as a CT scan or even an MRI, to visualize the level of stenosis. Currently, MRIs (Magnetic Resonance Imaging) happen to be the standard of care to visualize chronic back pain.