Manually-applied movement and mobilization of body parts as a healing activity has been used for centuries. Spinal manipulation (chiropractic) is most commonly used by chiropractors, but other healthcare practitioners including osteopaths and physiotherapists also perform spinal manipulation. In spinal manipulation, a relatively high velocity and low amplitude force is applied to the vertebral column.
Spinal manipulation is believed to restore normal motion and normalize physiology of the neuro-musculoskeletal system in particular and potentially other physiological systems affected by the dysfunction. Spinal manipulation is typically applied when dysfunctional areas of the vertebral column are found. Clinicians identify these areas based upon changes in the texture and tone of paraspinal soft tissues, the ability to elicit pain and/or tenderness from these tissues, asymmetries in hard or soft tissue landmarks, and restrictions in spinal joint motion (Chiropractic; 2012).
The concept of joint subluxation (a partial dislocation) in spinal manipulation proposes a biomechanical model of spinal pain that emphasizes normal function in the active, passive, and neural integration systems of the spine as a prerequisite for stability .
Spinal manipulation may produce a sustained change in the synaptic efficacy of central neurons by evoking a high frequency, bursting discharge from several types of dynamically-sensitive, mechanosensitive paraspinal primary afferent neurons.
Spinal manipulation could affect the nervous system by activating paraspinal sensory neurons during the maneuver itself and/or by altering spinal biomechanics. Biomechanical changes which follow the manipulation would, in turn, modulate paravertebral sensory neuron signal (Manipulation; 2012).