Is your neck pain affecting your balance?

Chronic neck pain, standing balance, and suboccipital muscle atrophy--a pilot study

 McPartland JM, Brodeur RR, Hallgren RC, JMPT 1997 Jan;20(1):24-9

This study was completed at the University of Michigan and looked at 7 chronic neck pain patients and 7 controls.

The purpose of the study was to examine the relationship between chronic neck pain, standing balance and sub-occipital (the base of the skull) muscle atrophy. 

Palpation was used to determine any somatic dysfunction (misalignment) of the upper cervical spine (top of the neck), a force platform was used to measure standing balance, and MRI was used to examine fatty infiltration (evidence of injury and disfunction) of the sub-occipital muscles.

The study found that chronic neck pain patients have almost twice the amount of somatic dysfunction (tenderness, asymmetry of joint position, restriction in range of motion, and tissue texture abnormality) as compared to normal subjects. 

The greatest changes where noted at C0-C1 (where your skull meets your neck) joints and the authors concluded that this area needed the greatest amount of consideration during evaluation.  (IE upper cervical chiropractic)

Further the study showed that chronic neck pain patients demonstrated a decrease standing balance using a force plate, and MR imaging indicated that they had increased atrophy of rectus capitus posterior minor and rectus capitus posterior major. 

The authors also have a wonderful discussion with a compelling hypothesis of the far reaching implications of chronic neck pain…

“Somatic dysfunction can cause a sustained facilitation of motor neurons and reflex contraction of muscles, which may lead to impaired circulation and localized tissue ischemia, followed by atrophic changes in muscles and fatty degeneration.  Muscle atrophy and degeneration have been associated with chronic pain.  Muscles in the cervical region also contain a high density of muscle spindles… Atrophy of these muscles might reduce proprioceptive input into the dorsal horn of the spinal cord and higher centers… A reduction of proprioceptive input might result in facilitation of neural activity which is perceived by the patient as chronic pain.”

In review:  Misalignment of the upper neck causes changes in the muscles and nerves in that area that affect your standing balance!  Standing balance influences your posture, your posture contributes to breathing, hormone production, blood pressure, and more because it’s all connected! Further, the longer you have the neck pain the more negative changes develop.  

Understanding Pain

Mechanisms of Musculoskeletal Pain

Bogduk N. The Journal of Orthopaedic Medicine 28(3) 2006

With three published texts and over 200 indexed articles , Nikolai Bogduk is one of the world’s foremost authorities on biomechanics of the spine and musculoskeletal pain, so when I came across this article I knew it would have some pertinent information that help us understand our patient’s pain.

Sample of Scalene Muscle trigger points and referred pain pattern

Key Points:

Pain transduction is ascribed to free or unencapsulated nerve endings with the following hierarchy of sensitivity; Periosteum, ligament, joint capsule, tendon, fascia, and muscle.

Reminder: that pain from a muscle is more commonly felt over the joint that that muscle moves.

How pain is created in the body: Mechanical or chemical stimuli affect free nerve endings in a peripheral nerve.  Central transmission is then the term used for propagation of action potentials from the first order neurons (free nerve endings) to the second order neurons which form tracks in the spinal cord to higher centers in the brain and thalamus.  Modulation then occurs in these tracks which involved intersegmental and descending pathways from the brainstem that inhibit and control the first synapse in this pain pathway.  Physiologically it then follows that modulation is one of the mechanisms that upper cervical chiropractic helps control pain occurring almost anywhere in the body!

Sensory (afferent) nerves and Sympathetic nerves contribute to mechanisms of inflammation in the body.  Chiropractic adjustments decrease sympathetic tone in the body, help to reduce inflammation and therefore pain.

Clinical Pearl: The next time you have an IME telling you that a patient has a ‘non-anatomical’ distribution of pain and therefore their pain is not genuine,  you can also use this article to cite that ‘Ongoing pain sensitizes the central nervous system to produce larger areas of pain’ that may not follow classic anatomical distributions.