The term “subluxation” has caused significant confusion and controversy within the healthcare community due to two vastly different meanings. In mainstream medical and orthopedic contexts, the word describes a verifiable anatomical condition seen on imaging. Conversely, a specific philosophy within chiropractic care uses the term to describe a much more abstract concept, known as the Vertebral Subluxation Complex (VSC), which allegedly impacts overall health. This debate highlights a major divide in how spinal health is understood and treated.
The Medically Recognized Definition
Within the medical and orthopedic fields, a subluxation is consistently defined as a partial or incomplete dislocation of a joint. This means the bones forming the joint have shifted out of their normal alignment, but the joint surfaces remain in partial contact. This is a diagnosable physical injury, distinct from a full dislocation where the joint surfaces are completely separated. Medically recognized subluxations can occur in any joint, such as the shoulder, knee, or ankle, and can also result from mild trauma to the spine.
This condition is verifiable through standard diagnostic imaging techniques, including X-rays, CT scans, and Magnetic Resonance Imaging (MRI). International bodies, including the World Health Organization (WHO), recognize this definition as a structural displacement. The medical definition of subluxation is assigned specific diagnostic codes, such as those found in the ICD-10 system, often in the injury-related “S” categories. Treatment typically involves standard medical or physical therapy interventions to manually reduce the subluxation or stabilize the joint.
The Chiropractic Theory of Vertebral Subluxation Complex
A distinct and controversial definition of subluxation exists within certain sectors of the chiropractic profession, known as the Vertebral Subluxation Complex (VSC). This theory describes a subtle, sometimes asymptomatic, misalignment or altered motion of a spinal vertebra. Proponents of the VSC claim this minor misalignment interferes with nerve function, which negatively affects the nervous system’s ability to communicate with the rest of the body. This alleged nerve interference is then claimed to cause a wide range of health issues, including systemic diseases and organ dysfunction.
The VSC is often described as a complex entity with five components:
- Kinesiopathology (abnormal movement)
- Neuropathophysiology (nerve dysfunction)
- Myopathology (muscle changes)
- Histopathology (tissue changes)
- Pathophysiology (abnormal function)
This concept has been central to some chiropractic philosophies since the profession’s founding in 1895. The historical idea is that correcting this minor spinal lesion restores the body’s innate healing ability by removing neurological interference.
Scientific Consensus on Systemic Effects
The claims made by the VSC theory—that minor vertebral misalignments cause systemic disease or organ dysfunction—lack support from the broader scientific and medical communities. Major medical organizations and scientific research do not support the idea that these subtle spinal lesions have a direct, measurable effect on general health or internal organ function. A critical review of the literature found no credible evidence linking the VSC to any specific disease process or suboptimal health condition requiring intervention beyond musculoskeletal care.
The neurological hypothesis, which suggests that a slight vertebral misalignment can significantly compress a spinal nerve to cause organ dysfunction, is not supported by neuroanatomy. Spinal nerves are more commonly affected by conditions like disc herniation or bony spurs. Even severe compressions rarely cause organic disease, as involuntary organ functions are largely regulated by the autonomic nervous system outside the spinal column.
The General Chiropractic Council, the regulatory body for chiropractors in the United Kingdom, explicitly stated that the VSC is an historical concept not supported by clinical research evidence for claims of causing disease. Diagnostic tools to reliably identify the VSC as a distinct clinical entity are also lacking. The concept of VSC is considered scientifically implausible by many medical experts when used to explain non-musculoskeletal health problems.
Current Role of Chiropractic Care
Despite the controversy surrounding the VSC, modern chiropractic care remains a widely accepted, evidence-based treatment for several common musculoskeletal complaints. The profession has largely shifted its focus toward functional improvement and pain management, aligning with scientific literature. Spinal manipulation is recognized in clinical practice guidelines as an effective intervention for acute, subacute, and chronic low back pain.
Research strongly supports the use of spinal adjustments for conditions such as neck pain, certain types of headaches, and other joint-related issues. Most clinical guidelines for both low back pain and neck pain recommend spinal manipulation as a treatment option. This evidence-based approach concentrates on restoring joint mobility and function, and reducing pain. The current role of chiropractic is focused on neuromusculoskeletal disorders, a specialization that has strong scientific validation.