For years, manual therapists have held firm to the belief that nerve root compression is the cause of pain arising from spinal misalignment. Pinched nerves are often blamed for unexplained neck and back pain. However, today most medical practitioners disregard the “pinched-nerve theory” due to the absence of neurological signs such as paresthesias, tingling, numbness, motor loss, etc.
Most researchers agree that pinched nerves do occur in extreme cases of trauma, muscle entrapments, and chronic degenerative disc disease. Some researchers dismiss the nerve root as a pain sensitive structure. To experience an example of nerve entrapment or ‘pinching’ of the nerve do this simple exercise: Lie on your side, place an arm above your head and rest on that arm for a few minutes. In a matter of time the arm will lose sensation as the nerve is stretched and compressed.
But, here’s the catch (no pun intended). Severe compression of a ‘healthy’ nerve may cause paresthesias, motor loss, sensory deficits, and loss of normal reflexes…there will be no pain. But, if the compression continues and the nerve’s dural sheath has rubbed raw, become inflamed (intraneural edema) and then is compressed…pain will be felt. This “silent nerve root compression syndrome” was first hypothesized by James E. Wilberger, MD in the Journal of Neurosurgery. His analysis indicates that time is required before functional alterations create mechanical nerve fiber deformation and associated pain.
Prolonged pressure on an inflamed sensory nerve or its adjacent capillary beds can accelerate the experience of pain (nociception) in the brain. Compression of a tethered nerve causes muscle cell contraction which leads to protective spasm, altered firing order patterns, faulty posture, wasted energy, and pain. However, it is rare for long term pain to exist as a result of a compressed nerve.
A far more common occurrence is pain caused by oxygen deprivation of the sensitive nerve tissues. This particular condition can be extremely painful, yet is a harmless and reversible process. Although chronic back pain is most commonly blamed on pathologies such as herniated discs, bone spurs, etc., the pain often results from mechanical strain on joint related tissues such as spinal ligaments, joint capsules and muscles.
Some forms of manual therapy can effectively treat both types of problems; the reduction in nerve function (tingling and numbness) as seen in piriformis and thoracic outlet syndromes, and also pain due to nerve fiber irritation. Myoskeletal Alignment (R) Techniques aim to improve joint mechanics in the affected area to allow joint and soft tissue healing.
The Myoskeletal Therapist holds the joint in a specific position with one hand and stretches the surrounding soft tissues with the other. As resistance is met, the client/patient isometrically contracts to a count of 5 and relaxes. Following the isometric muscle contraction, a pin-and-stretch articular mobilization releases motion-fixated joints. Pain is often immediately alleviated once abnormal joint position is corrected thereby allowing better movement with diminished nerve pain.
It appears that there will always be a certain amount of controversy over what symptoms qualify to be called a pinched nerve. Many nerve compression specialists will continue believing that neurological tissue can be compressed by bone only. Others maintain that a herniated disc and osteoarthritis are the primary culprits leading to reduced nerve signal.