The Chiropractic “subluxation” goes by a number of alternative names including joint dysfunction, segmental or somatic dysfunction, joint fixation and/or joint blockage.
Whatever the name, the Chiropractic lesion is a complex clinical pattern involving both biomechanical alterations such as stiffness and joint locking, in addition to changes to the nervous system including pain, muscle spasm and reflex increases or decreases in nerve function. Any joint in the spine and pelvis or in the extremities (hands and feet for example) can develop dysfunction.
Generally speaking there are three major processes or events in which a joint can become “subluxated” or dysfunctional. They are:
Trauma. This is the most common cause of joint dysfunction and can range from micro trauma, such as that created by poor posture or bad lifting habits
- or macro trauma, such as a whiplash injury in a car accident or hurting ones back by slipping and falling on a wet surface for example.
- Prolonged bed rest or fear avoidance behaviour whereby someone overzealously “protects” or “guards” a previously injured joint encouraging joint stiffness and contracture.
- Resolution of some more serious pathological condition (e.g. arthritis )
It appears that there is a combination of mechanisms involved in the events mentioned above that lead to the development of joint blockage. These include:
- Segmental muscle “spasm”/hyper tonicity
- Formation of adhesions or scar tissue in and/or around a joint
- Displaced disc fragments between the spinal joints
- Joint locking due to an entrapped bit of connective tissue
The joint dysfunction that develops has been described as “loss of accessory joint movement that cannot be produced by voluntary muscles”. When this accessory motion is lost, the joint can become painful. In addition to this, reflex effects can occur wherein certain muscles become hypertonic and others become inhibited. This imbalance in the activity of muscles can lead to the development of chain reactions of dysfunction throughout the body and create faulty movement patterns.
The above scenario describes how a local segmental problem, if left unchecked, can spread leading to more global or widespread dysfunction in areas not originally painful or problematic. An example is the evolution of headaches and/or neck pain arising from a chronic sacroiliac (SI) joint restriction in the pelvis.
Whatever the mechanism or event leading to joint dysfunction, the Chiropractic Adjustment aims to restore proper joint biomechanics and neurological function.