The Results of 47 Clinical Studies Examined in a 30-year Period


Objective: To determine the effectiveness of chiropractic treatment on patients with back or neck pain as compared to traditional allopathic treatments, a systematic review of the literature.

Reporting Sources:  A search for randomized clinical trials (RCT’s) on chiropractic therapy was conducted using a Medline search (1980-2001), citation tracking and directed reference acquisition from relevant publications.

Data Extraction:  Studies examined for this review specifically compared chiropractic manipulative therapy with traditional “mainstream” medical treatment (i.e. physiotherapy, mobilization, massage, deep heat, bed rest, prescriptive drugs, back school, corset, T. E. N. S., traction and/or placebo).  Exclusion criteria covered a wide range of diseases and conditions such as spondylolysis, root compression, osteoarthritus, psychological disturbances, pregnancy and vertebral collapse.

Data Synthesis: Three meta-analysis studies examining 35 RCT’s met the inclusion criteria for this review.  They were Assendelft, et al. (1996); Abenheim, et al. (1992); Koes, et al. (1991).

Additionally, twelve individual studies comparing the effectiveness of chiropractic manipulation to medical interventions in the treatment of musculoskeletal pain, not examined in the above-mentioned meta-analysis, were included.

Methods:  A study was ascertained to be positive, if the RCT determined that chiropractic was more effective than allopathic methodologies and/or placebos (i.e., the difference being statistically significant at a level of P<0.05).  A study was deemed negative, if the RCT reported favorable results for the non-chiropractic treatment, and neutral, if there was no discernable difference between the treatment outcomes.

Both objective and subjective outcome measures were used in the RCT’s reviewed.  The following represent the most prevalent outcome measures:  recovery rate; the amount of time required for the patient to return to work or normal activities; reductive change in the threshold of pain; and the patients’ efficacy of treatment rating.

Conclusions:  There is an obvious research need for direct attention focused upon the methodologies of design, execution, reporting, randomization (to eliminate bias), control and manipulation in future RCT’s for chiropractic.  This also should entail the development of standardized uniform guidelines for varying types of chiropractic clinical studies.  Accomplishing the above will afford subsequent statistical pooling, which is not wholly viable now.

The above notwithstanding, this review presents 47 clinical trials and studies that have been analyzed from the standpoint of their empiric outcomes.   These data strongly suggest that chiropractic manipulation offers superior results when compared to traditional allopathic treatments for musculoskeletal pain.


In the U.S., it is estimated that 85% of the population will be disabled by back pain at some point in their lives. Back pain is the most common cause of disability for people under the age of 45 in the U.S. Twelve million are considered to be back-pain impaired. Twenty percent of all military medical discharges from the U.S. armed forces are due to unresolved back pain. The costs associated with low back pain in the U.S. are estimated to be $60 billion annually. More than 30 million Americans will seek chiropractic care in 2006. Ninety percent of chiropractic users feel their treatment is effective. Chiropractic clearly is the most commonly utilized form of Complimentary Alternative Medicine (CAM) in the U.S.

Though long characterized as being a practice without scientific validation, few healthcare interventions have been assessed as extensively as spinal manipulation, both in terms of safety and effectiveness, over the last 40 years.

Yet, despite the high incidence and prevalence of back pain and the emergence of chiropractic to the forefront of CAM, its use and efficacy as a paradigm for back pain management remains controversial. A wide variety of therapeutic possibilities exist, both allopathically and in alternative healthcare, to treat back pain, thus, eliciting continuous debate regarding efficacy and safety.


Meta-analysis reviewing RCT’s addressing the efficacy of chiropractic manipulation have tended to focus primarily on the methodological quality of the studies involved, ignoring patient outcomes.


Chiropractic treatments in the RCT’s reviewed involved typically similar chiropractic techniques consisting of short lever, high velocity, low amplitude thrusts, spinal manipulative therapy and full spine adjustments.  Control group treatments included:  physiotherapy, traction, exercises, back school, soft tissue massage, transcutaneous muscle stimulation, corset, sham manipulations and medical treatment including analgesics, injections, bed rest and/or physiotherapy.

Forty-seven clinical trials and studies were analyzed from the standpoint of their empiric outcomes. Chiropractic manipulation was deemed more effective than allopathic treatment in 70% of the 47 clinical studies examined spanning a 30-year period.


Based upon the conclusions of the three meta-analyses reviewed, it is obvious that future chiropractic RCT’s must become as methodologically precise as possible. Additionally, it is important that specific studies address the comparative effectiveness of various chiropractic adjusting techniques upon pragmatic outcomes in the treatment of musculoskeletal dysfunction.

However, this author strongly believes it is imprudent to summarily discount a myriad of studies of chiropractic manipulation strictly upon the basis of the above-mentioned criticisms.  Unlike most medical maladies, which can, for example, be quantified and specifically monitored via blood tests, biopsies and other highly objective means, spine related disorders can and often have multiple origins as well as on going problems.  With drugs, we know the half-lives, thresholds, doses and interactions.  This is not the case with chiropractic manipulation.  By way of example, a certain medical protocol may mandate 5 cc’s of a specific antibiotic given in regulated doses over a defined period.  This is extremely precise, the protocol does not vary and its result can be specifically quantified with blood work.

Comparatively, a chiropractic patient could be experiencing low back pain resulting from a posterior rotated ilium.  This could be addressed by a variety of chiropractic interventions:  Gonstead/Diversified side-posture adjustment; sacral occipital technique (SOT); Thompson drop table thrust or an activator procedure, etc.  While it would be highly beneficial to have individual data on the relative degree of effectiveness of each technique, all manipulations above described can realign the ilium, relieving the associated pain to the patient.  At this point, the issue is moot as to whether the adjustment was Thompson drop or Gonstead side-posture.  What is most relevant was the fact that the pain was alleviated and the patient benefited.


There is a need for revisions in the methodologies of design, execution, reporting, randomization, control and manipulation in future RCT’s of chiropractic care.  This should entail the development of standardized, uniform guidelines for varying types of chiropractic clinical studies.  Accomplishing this will afford subsequent statistical pooling which is not entirely viable at present.  Such methodological improvements might be useful when directly addressing and, perhaps, refuting future criticism of chiropractic research. Such methodological enhancement would more effectively assess pragmatic outcomes of chiropractic therapeutics.

Specific studies and comparisons of various chiropractic manipulation techniques (i.e. Gonstead vs. Diversified, etc.) with respect to various musculoskeletal disorders treated would be of tremendous benefit to both the practicing clinician and teaching/research institutions and could establish more effective treatment protocols.  Additionally, there is a need to evaluate the long-term results of chiropractic manipulation, both in alleviating musculoskeletal disorders as well as side effect profiles.

Fundamental criticisms of chiropractic are two-fold.  First, there is an argument that there is a paucity of data to validate the effectiveness of chiropractic adjustments in the treatment of muscular/skeletal pain and second, treatment standardization among chiropractic clinicians varies widely.

With respect to the first criticism, it should be noted that there is a greater number of scientific trials for chiropractic spinal manual manipulation and it’s effectiveness than numerous intricate allopathic procedures routinely performed in hospitals daily. Few health care interventions have been assessed as extensively as chiropractic manipulation.

With regard to treatment standardization, it is important to note that chiropractic protocols of manual therapies are somewhat different from certain allopathic approaches to medicine.  There are over 100 adjusting techniques in chiropractic to accomplish a manual manipulation to relieve nerve pressure. Most are effective in relieving pain.  Although the shear number of techniques makes standardization a monumental task, a long term study of treatment protocols with respect to different injuries and patient complaints would be of significant benefit.

In summary, this review presents 47 clinical trials and outcome studies that have been reviewed from the standpoint of their empiric results.  These data strongly suggest that chiropractic manipulation offers results that are equivalent or superior to specific or combined traditional allopathic treatments for musculoskeletal low back and neck pain.  Chiropractic manipulation was deemed more effective than allopathic treatment in 70% of the 47 clinical studies examined spanning a 30-year period.

As suggested by the end points and outcomes of the studies presented, various traditional treatment protocols, such as bed rest, traction, surgery, physical and pharmaceutical therapies, appeared to be less effective than spinal manipulation in returning the patient to function and/or significantly reducing pain.  Based upon the studies examined, it appears likely that, for uncomplicated neck and low back pain not caused by fracture, tumor, infection or the cauda equina syndrome, chiropractic spinal adjustment is an effective intervention that can occupy a significant role in an interactive approach to back pain.

Dr. Steve Perram is a recent graduate of Texas Chiropractic College. Raised in southern California, Dr. Perram spent 25 years in the business world owning 4 different companies & acting as a business consultant for major corporations from coast to coast.  In 2001, Dr. Perram decided on a career change & began his quest to become a chiropractor.  He has been featured in Success Magazine, TVRO Technology, Personal Selling Power, High-Tech Marketing & Satellite Retailer magazines.  His business & professional backround is included in Personalities of America, The American Biographical Institute, Men of Distinction & the International Biography, Cambridge, England.  281-413-1276.


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