The Therapist Is In: When is it a Pinched Nerve?
The Therapist Is In
When is it a Pinched Nerve?
by Shannon Murphy, MPT
At some point we've all bumped a 'funny bone', twisted the wrong way, or suffered a shooting headache. Sharp and sudden pains are the body's way of alerting us to potential threats. But sometimes we develop pains that persist or radiate to other places. Why?
Nerves Are a Highway
The nervous system is a complex network that sends signals from place to place. As a result, sensation travels - up our arms, down our legs, to our brain and back out again. One can think of this like a roadmap...the spinal cord (part of the central nervous system) is similar to a highway, allowing lots of traffic to pass directly to and from the brain.
And like a highway, the spinal cord has exit ramps - small roots branch off the main cord, and form local "routes" that go to nearby muscles and tissue (peripheral nervous system). All works well when nerve-traffic flows smoothly - but accidents can happen along our internal roads just as easily as they happen on the interstate.
Cause vs. Effect
When problems arise in the peripheral nervous system, radicular pain (i.e. pain that travels a path) can develop. Many people are familiar with the leg and buttock syndrome known as sciatica (pronounced sigh AT ik uh). It is important to realize, however, that the term "sciatica" merely describes a pattern of pain - and does not inherently diagnose the reason for it. Pain in the sciatic nerve is generally an effect of some other process.
So what "causes" radicular pain? Primary factors include:
1. Bulging or herniated discs - while it is important to realize that not all disc problems cause pain (more on this in a future article), some certainly do. When pain radiates in the presence of an injured disc, this is typically because of irritation to the spinal nerve root (exit ramp) at that level. Bulges can place pressure on an already crowded area, reducing blood supply to the nerve, and creating tissue distress that we perceive as pain. In some cases, the distance that the pain travels is proportional to the amount of irritation involved (major accidents can cause major traffic jams!). But there are frequent exceptions, so it is important to keep the analogy in perspective.
2. Arthritis - degenerative changes are a normal part of aging. In some people, however, the process happens too quickly or with too much concentration in a specific area. When the spine develops arthritis (spondylosis), the amount of space surrounding the spinal cord and/or nerve roots can be reduced (stenosis). This again can compromise blood supply and cause the nerve to become irritable.
3. Muscles - muscles that are tight, or always 'turned on', can squeeze the nerves that pass through them. In some people, their specific anatomical layout makes them more susceptible to nerve entrapments than others. However, muscles themselves can refer pain down their fibers without involving the nerves, per se - trigger points seem to use a more chemical process, although the phenomenon isn't completely understood.
In summary, a "pinched nerve" really refers to any part of the peripheral nervous system that is being irritated...regardless of whether it is being truly pinched or not.
What can be done about it? Visiting a trusted healthcare professional is always good advice. And so is reading this column! Have a question you'd like answered? Email the author: smurphy@bodysensePT.com
This series of columns are by Shannon Murphy, MPT, Owner/Director of BodySense PT. 9 Saint Paul St, 3rd Floor, Boonsboro, MD 21713. 301-432-8585 phone, 301-432-1987 fax, firstname.lastname@example.org.