What are Chiropractic Adjustments (Spinal Manipulation Therapy) actually doing?

Understanding Spinal Manipulation: Benefits and How It May Work

Back pain and neck pain are the most common musculoskeletal complaints people seek my care for. One treatment modality I commonly use with patients is spinal manipulation therapy or otherwise known as spinal adjustments by chiropractors (I interchange the two terms in my everyday language, so bear with me when reading this). For many of my patients, spinal manipulation is an effective treatment option to help reduce pain, improve movement, and support recovery.

Spinal manipulation is a hands-on treatment commonly provided by chiropractors, but also used by physiotherapists and osteopaths with appropriate training. It involves applying a controlled force to specific joints of the spine. While many people are familiar with the characteristic "popping" sound that may accompany treatment, research suggests that the benefits of spinal manipulation are likely related to how it affects the nervous system rather than simply changing the position of spinal joints.

What Are the Potential Benefits of Spinal Manipulation?

Pain Relief

One of the most widely studied benefits of spinal manipulation is its ability to help reduce back and neck pain. Research has found that spinal manipulation can provide improvements in pain levels for some people with acute and chronic spinal pain and may be as effective as other recommended conservative treatments for certain conditions (Bronfort et al., 2004; Shekelle et al., 2017).

Many patients report feeling relief shortly after treatment, although individual responses can vary.

Improved Movement and Function

Pain often causes people to move differently or avoid certain activities altogether. Studies have shown that spinal manipulation may help improve mobility and physical function, making everyday activities easier and more comfortable (Bronfort et al., 2004).

When pain decreases, people are often able to return to normal movement patterns and gradually rebuild confidence in their bodies.

Supporting Recovery

Spinal manipulation is often used as part of a broader treatment plan that may include exercise, lifestyle advice, rehabilitation, and self-management strategies. Research suggests that combining hands-on treatment with active approaches to recovery may help patients achieve the best long-term outcomes.

How Does Spinal Manipulation Work?

For many years, spinal manipulation was thought to work primarily by "realigning" the spine or correcting joints that were believed to be out of place. However, modern research suggests that the explanation is more complex.

Today, scientists believe spinal manipulation may work through a combination of neurological, muscular, and psychological effects.

Influencing the Nervous System

One of the leading theories is that spinal manipulation affects how the nervous system processes pain.

The joints, muscles, and ligaments of the spine contain thousands of sensory receptors that constantly send information to the brain. When spinal manipulation is applied, these receptors are stimulated, which may alter the way pain signals are processed by the nervous system (Coronado et al., 2012).

Research has shown that spinal manipulation can reduce pain sensitivity both near the treated area and sometimes in other parts of the body. This suggests that the treatment may influence central pain-processing mechanisms rather than acting only on the local tissues (Coronado et al., 2012).

Helping Muscles Work More Efficiently

Pain can disrupt normal muscle function. Some muscles become overactive while others may become inhibited or less responsive.

Research has found that spinal manipulation can produce short-term changes in muscle activity and motor control, potentially helping the body move more comfortably and efficiently (Lascurain-Aguirrebeña, Newham and Critchley, 2016).

Reducing the Feeling of Stiffness

Many people describe feeling less stiff and more mobile after treatment.

Interestingly, studies suggest that the sensation of stiffness may not always reflect actual physical stiffness in the spine. Instead, it may be influenced by how the brain interprets sensory information from the body. Changes in pain perception and muscle tension may therefore contribute to the feeling of increased flexibility after treatment (Lascurain-Aguirrebeña, Newham and Critchley, 2016).

Influencing Natural Pain-Control Systems

The body has its own internal mechanisms for regulating pain. Some researchers believe spinal manipulation may help activate these natural pain-control pathways, allowing the nervous system to reduce the intensity of pain signals reaching the brain (Coronado et al., 2012).

This may help explain why some people experience improvements in symptoms shortly after treatment.

Is Spinal Manipulation About "Putting Bones Back Into Place"?

Modern research suggests that the benefits of spinal manipulation are unlikely to be explained by significant structural changes in the position of spinal joints.

A recent systematic review found limited evidence that spinal manipulation creates lasting anatomical changes capable of explaining improvements in pain or function (Young et al., 2024).

Instead, researchers increasingly believe that spinal manipulation works primarily by influencing the nervous system, muscle function, and pain-processing mechanisms.

A Modern Understanding of Care

Today, many healthcare professionals view spinal pain through a biopsychosocial lens. This means recognising that pain is influenced by a combination of physical, neurological, psychological, and lifestyle factors.

The benefits of spinal manipulation may therefore arise from several interacting mechanisms, including:

• Changes in pain processing within the nervous system

• Improvements in movement and muscle function

• Increased confidence in movement

• Reduced fear and tension

• Positive therapeutic interactions between patient and practitioner

• Support for active recovery strategies

Rather than being a simple mechanical treatment, spinal manipulation appears to influence multiple systems involved in pain and recovery.

Final Thoughts

Spinal manipulation is a commonly used treatment that may help reduce pain, improve mobility, and support recovery for some people with back and neck pain. While researchers continue to investigate exactly how it works, current evidence suggests that its effects are likely driven by changes within the nervous system, muscles, and pain-processing pathways rather than by physically realigning the spine.

As part of an evidence-informed approach to care, spinal manipulation can be one useful tool among many to help people move better, feel better, and return to the activities they enjoy.

References

Bronfort, G., Haas, M., Evans, R. and Bouter, L. (2004) 'Efficacy of spinal manipulation and mobilisation for low back pain and neck pain: a systematic review and best evidence synthesis', The Spine Journal, 4(3), pp. 335–356.

Coronado, R.A., Gay, C.W., Bialosky, J.E., Carnaby, G.D., Bishop, M.D. and George, S.Z. (2012) 'Changes in pain sensitivity following spinal manipulation: a systematic review and meta-analysis', Journal of Electromyography and Kinesiology, 22(5), pp. 752–767.

Lascurain-Aguirrebeña, I., Newham, D. and Critchley, D.J. (2016) 'Mechanisms of action of spinal mobilizations: a systematic review', Spine, 41(2), pp. 159–172.

Shekelle, P.G., Paige, N.M., Miake-Lye, I.M., et al. (2017) The Effectiveness and Harms of Spinal Manipulative Therapy for the Treatment of Acute Neck and Lower Back Pain.

Washington, DC: Department of Veterans Affairs Evidence Synthesis Program.

Young, K.J., Leboeuf-Yde, C., Gorrell, L., et al. (2024) 'Mechanisms of manipulation: a systematic review of the literature on immediate anatomical structural or positional changes in response to manually delivered high-velocity, low-amplitude spinal manipulation', Chiropractic & Manual Therapies, 32, Article 13.