The Hidden Science Behind Your Chiropractor’s Techniques

Chiropractic care has gained popularity over the years as a holistic approach to treating various musculoskeletal issues. Central to this practice are chiropractic manipulations, often accompanied by audible pops, speed of a manipulation and concerns about vascular safety, particularly in the neck region. In this post, we delve into these elements, shedding light on what occurs during chiropractic adjustments, their effects, and the safety considerations associated with them.

Audible Pops: What Are They and Why Do They Occur?

One of the most intriguing aspects of chiropractic manipulations is the often-heard audible pops or cracks during adjustments. Contrary to popular belief, these sounds are not bones cracking or breaking. Instead, they are the result of gas bubbles being formed and breaking from within the synovial fluid within the joints (2). This phenomenon is known as cavitation.

During a manipulation, when the joint is stretched or moved beyond its usual range of motion, the pressure within the joint decreases. This sudden decrease in pressure causes gases (such as nitrogen and carbon dioxide) dissolved in the synovial fluid to form bubbles (2). When these bubbles collapse or burst, they produce the characteristic popping sound. It's akin to the sound produced when opening a carbonated beverage.

The audible pops are not necessarily indicative of the effectiveness of the manipulation. Some adjustments may not produce any sound at all, yet they can still be beneficial in restoring the function of the spine or joints and relieving tension and pain.

Manipulation Vs. Mobilization

Faster manipulations, often referred to as high-velocity, low-amplitude (HVLA) thrusts, involve a quick and precise force applied to a joint to restore its normal function. These rapid movements aim to mobilize restricted joints and improve range of motion. However, the force and depth of the manipulation must be carefully controlled to avoid causing injury, especially in delicate areas like the neck.

Slower techniques, such as mobilization or soft tissue manipulation, may be preferred in certain cases, particularly for patients who are more sensitive or have underlying health issues.

Ultimately, the use of a HVLA or a mobilization should be tailored to the individual needs and comfort level of the patient, and performed by a skilled and experienced chiropractor.

Vascular Concerns in the Neck: Understanding the Risks

Chiropractic manipulations, particularly those involving the cervical spine (neck), have raised concerns regarding the potential risk of vascular injuries, such as stroke or dissection of the vertebral or carotid arteries.

The vertebral and carotid arteries supply blood to the brain, and their proximity to the cervical spine makes them susceptible to injury during forceful neck manipulations. One study found that the arteries in the head/neck were able to elongate on average 33.5%, whereas the average vertebral artery length change during spinal manipulation was 1.1 to 15.1% (6). While such complications are rare, they underscore the importance of thorough assessment and appropriate screening before performing cervical adjustments.

Chiropractors are trained to recognize the signs of vascular compromise and employ specialized techniques, such as gentle mobilization or instrument-assisted adjustments, to minimize risks while still achieving therapeutic outcomes.

Effects of Chiropractic Manipulations: Beyond the Audible Pops

The effects of chiropractic manipulations extend beyond the audible pops or cracks. When performed correctly, these adjustments can:

• Restore Joint Function: Chiropractic manipulations help restore proper biomechanics and alleviate joint dysfunction (9).

• Relieve Pain and Tension: Manipulations can reduce muscle tension, alleviate nerve compression, and promote the release of endorphins, leading to pain relief and improved mobility (1).

• Enhance Nervous System Function: Proper spinal function ensures optimal communication between the brain and the rest of the body, enhancing overall nervous system function and promoting wellness (1).

• Improve Range of Motion: Manipulations help restore joint flexibility and range of motion, allowing for smoother and more coordinated movements (4).

Conclusion

Chiropractic manipulations encompass a range of techniques aimed at restoring proper joint function, relieving pain, and promoting overall well-being. While the audible pops, speed of manipulation, and vascular concerns may raise questions and considerations, a well-trained and skilled chiropractor can safely and effectively perform adjustments tailored to individual needs.

As with any healthcare intervention, it's essential to communicate openly with your Victoria chiropractor, discuss any concerns or preferences, and ensure that the treatment plan aligns with your health goals and comfort level. When approached thoughtfully and responsibly, chiropractic care can be a valuable component of holistic wellness and musculoskeletal health.

References:

1.     Bialosky JE, Bishop MD, Robinson ME, Zeppieri G Jr, George SZ. Spinal manipulative therapy has an immediate effect on thermal pain sensitivity in people with low back pain: a randomized controlled trial. Phys Ther. 2009;89(12):1292-1303. doi:10.2522/ptj.20090058

2.     Cassidy JD, Boyle E, Côté P, et al. Risk of Vertebrobasilar Stroke and Chiropractic Care: Results of a Population-Based Case-Control and Case-Crossover Study. Spine. 2008;33(4 Suppl):S176-S183. doi:10.1097/BRS.0b013e3181644600

3.     Evans, D. W. (2022). Why is the prevailing model of joint manipulation (still) incorrect?. Chiropractic & manual therapies, 30(1), 51.

4.     Galindez-Ibarbengoetxea, X., Setuain, I., Andersen, L. L., Ramirez-Velez, R., González-Izal, M., Jauregi, A., & Izquierdo, M. (2017). Effects of cervical high-velocity low-amplitude techniques on range of motion, strength performance, and cardiovascular outcomes: a review. The Journal of Alternative and Complementary Medicine, 23(9), 667-675.

5.     Herzog W, Leonard TR, Symons B, Tang C, Wuest S. Vertebral artery strains during high-speed, low amplitude cervical spinal manipulation. J Electromyogr Kinesiol. 2012;22(5):740-746. doi:10.1016/j.jelekin.2012.02.006

6. Lindsay M. Gorrell, Andrew Sawatsky, W Brent Edwards & Walter Herzog (2023) Vertebral arteries do not experience tensile force during manual cervical spine manipulation applied to human cadavers, Journal of Manual & Manipulative Therapy, 31:4, 261-269, DOI: 10.1080/10669817.2022.2148048

7.     Rubinstein SM, van Middelkoop M, Assendelft WJ, de Boer MR, van Tulder MW. Spinal  manipulative therapy for chronic low-back pain: an update of a Cochrane review. Spine. 2011;36(13):E825-E846. doi:10.1097/BRS.0b013e3182197fe1

8.     Kosloff, T., Elton, D., Tao, J., & Bannister, W. (2015). Chiropractic care and the risk of vertebrobasilar stroke: results of a case–control study in U.S. commercial and Medicare Advantage populations. Chiropractic & Manual Therapies, 23. https://doi.org/10.1186/s12998-015-0063-x.

9.     Vining, R., Long, C., Minkalis, A., Gudavalli, M., Xia, T., Walter, J., Coulter, I., & Goertz, C. (2020). Effects of Chiropractic Care on Strength, Balance, and Endurance in Active-Duty U.S. Military Personnel with Low Back Pain: A Randomized Controlled Trial.. Journal of alternative and complementary medicine. https://doi.org/10.1089/acm.2020.0107.