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Beneficial Effects of Activator on Osteoarthritis Research

Beneficial effects of Activator Chiropractic Instrument in a Rabbit Model of Osteoarthritis – Research Review and Excerpts


This is a review and excerpts of a 2020 research study from  Scientific Reports on the improvement in Osteoarthritis measures in  rabbits with the use of an Activator instrument, specifically an Activator V, which we use in our Caledonia Chiropractic office.

The research paper is titled “Beneficial effects of manually assisted chiropractic adjusting instrument in a rabbit model of osteoarthritis

This article was forwarded to me from the Activator Methods International founder Dr. Arlan Fuhr.  He seemed very excited to pass along this research and after I read it I can see why.  Here is the press release he sent along with the link to this research article:

Activator Methods International Logo 2020

Promising Therapy for Osteoarthritis


August 25, 2020

CONTACT [for Activator Methods]:

Customer Service [for Activator Methods], 1-800-598-0224,


Article Cites “Promising Therapy” for Osteoarthritis

 (PHOENIX) – Activator Methods International, Ltd. announced today that recent research results regarding the Activator V® electronic chiropractic adjusting device has been published in the prestigious Scientific Reports, a journal publication of Nature.

 The research was carried out in Madrid, Spain and supported by grants from the Spanish Chiropractic Association, the Spanish Ministry of Economy and Competitiveness and the Carlos III Institute of Health. Results demonstrated the benefits of chiropractic manipulation using the Activator V® for induced osteoarthritis (OA) in animals. The study found improvements in subchondral bone (the layer of bone located just below cartilage in a joint) as well as in the cartilage itself. Additionally, the Activator V® decreased joint inflammation and may be effective in reducing pain.

The study concluded that “…Activator V® may represent a promising alternative therapy for the treatment of OA.”

Activator Methods chairman and founder Dr. Arlan W. Fuhr said, “We certainly have plenty of clinical and anecdotal evidence that chiropractic adjustment using an Activator instrument can facilitate significant improvement in patients with osteoarthritis. We now have another detailed scientific study that confirms what we’ve found to be true in practice.”

Osteoarthritis is one of the most common chronic diseases that affects all anatomical structures of a joint, including cartilage, subchondral bone and connective tissue that lines the inside of a joint capsule. The disease affects about 15% of the global population between the ages of 25 and 75 years, with prevalence that increases significantly with age. More than 70% of those over the age of 65 suffer with osteoarthritis.

There is currently no effective pharmacotherapy available for osteoarthritis. Patient treatment is typically based on established guidelines for structural conservation of the joints by correcting posture and avoiding joint overload.

The journal article appears in the August 2020 issue of Scientific Reports.

Full article:

 About Activator Methods International, Ltd.

Activator Methods International has been providing chiropractic care, resources and training since 1967. Founded on the principles of clinical research, the company’s major contribution to chiropractic care is discovery and development of the world’s most popular instrument adjusting technique, the Activator Method.

About Scientific Reports

Scientific Reports is an online, open access, multidisciplinary publication that publishes research in all areas of the biological, chemical, physical, and earth and environmental sciences. Scientific Reports provides rapid peer review and publication of research without barriers to access.

Here are my favourite excerpts from the study and some additional information to think on:


“Osteoarthritis (OA) is a degenerative disease characterized by injury of all joint tissues. Our previous study showed that in experimental osteoporosis, chiropractic manipulation (CM) exerts protective effects on bone. We here assessed whether CM might ameliorate OA by improving subchondral bone sclerosis, cartilage integrity and synovitis. Male New-Zealand rabbits underwent knee surgery to induce OA by anterior cruciate ligament injury. CM was performed using the chiropractic instrument ActivatorV 3 times/week for 8 weeks as follows: force 2 setting was applied to the tibial tubercle of the rabbit right hind limb (TM-OA), whereas the corresponding left hind limb received a false manipulation (FM-OA) consisting of ActivatorV firing in the air and slightly touching the tibial tubercle. After sacrifice, subchondral bone integrity was assessed in the tibiae by microCT and histology. Cartilage damage and synovitis were estimated by Mankin’s and Krenn’s scores, respectively, and histological techniques. Bone mineral density and content in both cortical and trabecular compartments of subchondral bone decreased in OA rabbits compared to controls, but partially reversed in the TM-OA group. Trabecular bone parameters in the latter group also showed a significant improvement compared to FM-OA group. Moreover RANKL, OPG, ALP and TRAP protein expression in subchondral bone significantly decreased in TM-OA rabbits with respect to FM-OA group. CM was associated with lower Mankin’s and Krenn’s scores and macrophage infiltrate together with a decreased protein expression of pro-inflammatory, fibrotic and angiogenic factors, in TM-OA rabbits with respect to FM-OA. Our results suggest that CM may mitigate OA progression by improving subchondral bone as well as cartilage and synovial membrane status.”

“Preclinical and clinical studies point to the observed alterations in subchondral bone as an important OA
pathogenic factor8. In fact, studies in animal models of combined osteoporosis (OP) and OA (OPOA) demonstrate
that OP induces cartilage damage9. In this setting, the observed significant correlation between deterioration
of subchondral bone and cartilage injury indicates that alterations in subchondral microstructure aggravate
cartilage damage10. Currently, no effective pharmacotherapy is available for OA, and the treatment of OA patients is based
on established guidelines for structural conservation of the joints by correcting postures and avoiding joint overloads11. Likewise, good physical activity is recommended since mechanical stimulation can improve the initial stages of OA11.”

“In this regard, low energy shock wave devices, such as ActivatorV Adjusting Instrument (Activator Methods International, Phoenix, AZ) used for chiropractic manipulation (CM)16 might be an alternative to ESWT in OA treatment. Compared to ESWT [Extracorporeal shock wave therapy] generators, the peak amplitude of the pressure waves generated by ActivatorV is 20-fold smaller17. Previous data in cells cultures17 and synthetic blocks analogous to spinal tissues18 have demonstrated that the input force exerted by ActivatorV produces a maximum kinetic energy of 0.3 J; which is below the energy necessary to induce tissue damage19. Recently, we reported that CM, using ActivatorV, induces an improvement in bone mineral density (BMD) and bone microarchitecture in an experimental rat model of OP20. Considering these previous findings and given the impact of subchondral bone in cartilage damage in OA, we hypothesized that ActivatorV-based CM might prevent the evolution of OA at least in part through the improvement of this bony tissue. In this study, we used male New-Zealand rabbits undergoing knee surgery to induce OA, as a well- characterized animal model21.”

How often were the rabbits in this research study adjusted using the Activator V instrument?

The rabbits in this study were adjusted 3x/week for 8 weeks during this study.  The one leg was adjusted specifically at the joint that the study was analyzing and the other leg was “sham adjusted”.  The sham adjustment is where the Activator instrument is touching the joint and makes a sound, but no force is put into the joint.

What results did this research study find with regards to osteoarthritis?

The study found some very positive and interesting findings, such as:

“CM improves microstructural parameters of subchondral bone in OA rabbits.”

“CM counteracts the increase of subchondral bone remodeling in OA rabbits.”

“CM modifies cartilage and synovial membrane damage in OA rabbits.”

“CM affects macrophage infiltration in synovial membrane of OA rabbits.”

CM stands for Chiropractic Manipulation in this study.  OA stands for Osteoarthritis.

They even have images in the article which show the difference in the bone quality between the control group, true manipulation group, and false manipulation group.  Worth checking out (at the article link above)  if you are curious to imaging what the findings mean in a visual sense.

Discussion points mentioned in the study:

“In the present study, the observed positive effects of CM in this OA model in rabbits seem to support the association between subchondral bone remodeling and cartilage tissue integrity. Moreover, CM positively affected several OA-related changes in the synovial membrane, including inflammation and angiogenesis and extracellular matrix remodeling, in this animal model.”

“The true mechanisms whereby CM could exert these observed beneficial effects on damaged cartilage are unknown.”

-The reason that these positive effects occur are unknown but there was some theories suggested.  The theory that caught my attention the most was:

“In addition, it has been speculated that the mechanical impulse generated by ActivatorV and the associated joint movement during spinal manipulative therapy could modulate the entry of sensory afferences (mechanoreceptors) to the central nervous system
with subsequent modulation of muscle tension19. This muscular tension could achieve considerable articular reconditioning, relieving the overload to which the knee is exposed and thus, improving the status of the damaged cartilage in the context of OA.”

“This study, however, presents some weaknesses and limitations. Thus, the results of the current study obtained in rabbits may not be translatable to humans due to the marked differences in joint biomechanics and gait of these animals compared to humans53. In addition, the number of animals used in this study was small, which may cause bias in statistical analysis and limits the statistical power in some analyzed parameters. In line with the above, further studies are strongly recommended to establish the role of CM in OA improvement as suggested by our present data.

In conclusion, the present study in rabbits suggests that CM may retard the progression of OA through an improvement of subchondral bone status and cartilage damage, associated with an ameliorated synovial damage.”

I hope that this has made you interested to learn more.  If you have questions or would like to discuss please connect to us in Caledonia at Caledonia Chiropractic – Dr. Callum Peever



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