What Is Chiropractic?

The simple explanation and what most people know

Chiropractic is a health care profession concerned with diagnosis, treatment, and prevention of injuries and disorders of the neuromusculoskeletal systems (nerves, muscles, bones). The chiropractic profession emphasizes the natural power of the body to heal itself (homeostasis), and therefore chiropractic practice does not include the use of drugs and surgery. Patients requiring these invasive interventions are referred to medical specialists. All patients receive an extensive consultation, history, and examination to help determine the specifics of their injury. After a differential diagnosis is provided, treatment options are discussed.

The natural, or non-invasive, treatment approaches used by chiropractors include the following: manual treatments, physical therapy modalities, exercise programs, nutritional advice, orthotics, lifestyle modifications, and patient education. Because of its proven effectiveness, there is an emphasis on adjusting the joints of the body, especially the spine.

Approximately 95% of chiropractic patients complain of musculoskeletal pain (e.g. back pain, neck pain, headaches, pain in the shoulder, carpal tunnel syndrome, strain/sprain injuries of almost any joint or muscle group). The other 5% of chiropractic patients are treated for conditions caused by spinal dysfunction. The effect of this dysfunction may be expressed through the nervous system. Such conditions often include dysmenorrhea, asthma and other respiratory dysfunctions, colic, constipation and other digestive dysfunctions, etc. 1

Please be aware that this does NOT mean that Chiropractic treats or cures asthma, for example, or any other systemic pathology directly.  However, if through chiropractic treatment and spinal adjustments these conditions appear to improve, such as requiring less frequent use of inhalers, then it might be beneficial for patients to receive this type of treatment.  Although it is unusual for patients to visit our office with a request for treating these “non-chiropractic” conditions, some patients do report an improvement of these conditions when we treat their primary issue, which may be neck pain or low back pain.

Most people are aware of the benefits of chiropractic treatment for musculoskeletal conditions including back pain, strain/sprain injuries, headaches, etc.  But few patients or medical doctors know of the benefits that chiropractic adjustments can provide through the influence of adjustments on the central nervous system, specifically the Autonomic nervous system which consists of the sympathetic and parasympathetic nervous systems.   It all starts with proprioception…  See below.

The scientific explanation and what most people don’t know

Chiropractic adjustments have a direct effect on musculoskeletal structures, including muscles, ligaments, joints, joint capsules and surrounding myofascial tissues, and reduce pain while increasing joint motion. (as stated above)  As a side benefit, chiropractic adjustments have an indirect effect on the autonomic nervous system by down regulating the sympathetic nervous system (fight or flight system) and promote the para-sympathetic nervous system (rest and repair system).  This is done through the effects the chiropractic adjustments have on the joint capsules and the body’s proprioception mechanism through the mechanoreceptors in the joints and periarticular tissues.   As such, some chiropractic patients report non-musculoskeletal benefits, or improvement in organic function.  This is not to state that chiropractic adjustments treat systemic pathology, but does suggest that some patients who have systemic type symptoms may benefit from chiropractic care even in the absence of pain.  Below is research to support this statement.

To better understand the above statement, below are some definitions and an explanation as to what is happening at the joint being adjusted.

Proprioception: The body’s ability to know where it is in space.  This information is provided by the mechanoreceptors, Types 1, 2, 3, & 4.

Mechanoreceptors: Types 1, 2, & 3 receptors are at the joints and provide the following information to the brain:

Types 1, 2, & 3 mechanoreceptors adapt rapidly and will stop firing.  (For example, that’s why you don’t “feel” your watch after having put in on. The body adapts to the sensation.)

Encapsulated mechanoreceptors and free nerve endings have been identified in the periarticular tissues of all major joints of the body, and in every articular tissue except cartilage. 2,3,4,5

The last mechanoreceptors, Type 4, are free nerve ending (nociceptors) or pain receptors that DO NOT adapt. The pain fibers keep firing when stimulated.

Restricted joint motion causes an increase firing in nociceptive axons…and a decrease firing of large diameter mechanoreceptor axons. 6  Therefore, decrease joint motion causes an increase in the perception of pain.  One of the functions of chiropractic adjustment is to increase joint motion in fixated joints and therefore decreasing Type 4 free nerve endings from firing and registering as pain.

Type 4 mechanoreceptors (nociceptor or pain receptors) reflexively activates the sympathetic nervous system. 7  Nociceptive input can cause symptoms such as sweating, pallor, nausea, vomiting, abdominal pain, sinus congestions, dyspnea, cardiac palpitations, and chest pain. 8  These are symptoms often associated with systemic or visceral problems.  If a chiropractic adjustments can reduce the firing of the nociceptor or free nerve ending then as a side benefit, the adjustment may also reduce the symptoms caused by the stimulation of the sympathetic nervous system.  The sensory cortex of the brain is bombarded with 1 trillion conscious impulses every second (pain is a conscious impulse), but we are aware of only about 50 bits of information per second. 9  Chiropractic adjustments decrease the nociceptor input to the spinal cord and decreases the “hyperexcitable central state”. 10 

About 1 in 4 (23%) of adult patients experienced positive non-musculoskeletal benefits after chiropractic adjustments.11  The study included 1509 patients who reported unexpected positive non-musculoskeletal benefits to include:

 

Footnotes

  1. Chapman-Smith, David, The Chiropractic Profession. NCMIC Group 2000; 1-2
  2. Freeman, M.A.R. and Wyke, B.D.: The Innervation of the Knee Joint: An Anatomical and Histological Study in the Cat. J. Anat., 101:505-532, 1967.
  3. O'Connor, B.L.: The Mechanoreceptor Innervation of the Posterior Attachments of the Lateral Meniscus of the Dog Knee Capsule. J. Neurophysiol., 47:41-54, 1982.       
  4. O'Connor, B.L. and Gonzales, J.: Mechanoreceptors of the Medial Collateral Ligament of the Cat Knee Joint. J. Anat., 129:719-729, 1979.
  5. Ramcharan, J.E. and Wyke, B.D.: Articular Reflexes in the Knee Joint; An Electromyographic Study. Am. J. Physiol., 223:1276-1280, 1972.
  6. Hooshmand H. Chronic: reflex sympathetic dystrophy, prevention and management.  Boca Raton, FL CRS press: 1993 p33-35.
  7. Kabell J. Sympathetically maintained pain.In:  Willis W. ed.  Hyperalgesia and Allodynia.  Raven Press. NY:1992
  8. Nansel D. SzlazakM.  Somatic dysfunction and the phenomena of visceral disease simulation:  A probable explanation for the apparent effectiveness of somatic therapy in patients presumes to be suffering from visceral disease.  J. Manipulative Physiol Ther. 1995: 118:379-97.
  9. Furman and Gallo.  The neurophysicos of Human Behavior. CRC press, 2000 Pg 274.
  10. Patterson M. The spinal cord: participant disorders. J Spinal Manip: 1993:9(3) 2-11.
  11. Lebeuff-Yde C, Axen I et al.  Types & Frequencies of Improved nonmusculoskeletal symptoms reported after Chiropractic spinal manipulative therapy.  JMPT 1999; 22(9):559-564.