If you’ve ever wondered what actually goes on inside the body when a chiropractor performs an adjustment, beyond the familiar “pop”, you’re not alone. Chiropractic care has often been described in terms of bones “being put back into place,” but modern science tells a much richer story about how these skilled, precise adjustments influence the nervous system, not just the spine.
A Quick Recap: What an Adjustment Is
A chiropractic adjustment is a high-velocity, low-amplitude (HVLA) thrust delivered to a joint that isn’t moving as well as it should. That little click you hear? It’s the release of tiny gas bubbles from the joint fluid as the joint surfaces separate, a normal physical phenomenon called cavitation.
But that sound isn’t the therapeutic target. The real action happens inside your nervous system.
It’s About the Nervous System, Not Just the Spine
Dr. Heidi Haavik, a chiropractor with a PhD in human neurophysiology, has spent over a decade studying what happens to the brain and nervous system when chiropractors adjust dysfunctional spinal segments. Her work flips the old “bones into place” model on its head and gives us a scientifically plausible mechanism rooted in neurophysiology.
Instead of focusing on bones realigning, Haavik’s research shows that adjustments change how the brain processes information from the body, especially from joints, muscles, and fascia, and how it sends motor commands back out. This sensorimotor dialogue is central to how you move, react, balance, and adapt.
Adjustments Influence Brain Function and Sensorimotor Integration
In her research, Haavik and her team have used techniques like:
- Somatosensory-evoked EEG (to track how the brain responds to sensory input),
- Transcranial magnetic stimulation (TMS) (to look at motor cortex output),
- Muscle activation studies, and
- Neuroplasticity measures.
These studies consistently find that chiropractic adjustments can change how the brain and nervous system integrate sensory information and drive muscles more efficiently.
In one study, subjects showed increased drive from the brain to muscles (i.e., better neural command and muscle activation) and reduced muscle fatigue after a single session of spinal adjustments.
A Look at Neuroplasticity
One of the most intriguing findings from chiropractic neuroscience research is that adjustments can lead to neuroplastic changes, that’s the brain’s ability to change and adapt. Studies show changes in the activity of brain regions involved in movement, sensory interpretation, and even higher level processing after chiropractic care.
In practical terms, this means that adjustments help the nervous system better interpret signals from the body, leading to improved coordination, balance, strength, and motor control.
Beyond Movement: Potential Effects on Mood and Sleep
The nervous system doesn’t only control muscles. It also influences other aspects of health like stress response, sleep patterns, and emotional regulation. Heidi’s team has proven with the use of recent EEG studies, chiropractic care can alter brain activity patterns which helps with improved sleep quality and reduced anxiety and fatigue.
This doesn’t mean adjustments are a cure all, but it does emphasize that chiropractic care interacts with the central nervous system in ways we’re just beginning to understand.
So What’s the Adjustment Actually Doing?
🔹 Not just moving bones. It’s about restoring optimal signal flow between your body and brain.
🔹 It’s a nervous system reset. Adjustments help the brain better interpret sensory inputs from joints and muscles, and respond with more coordinated motor output.
🔹 It influences neuroplasticity. The nervous system changes in response to experience, and adjustments are one of those experiences that can shift how the brain and body communicate.
🔹 Real measurable effects. Research shows changes in muscle activation, cortical drive, and brain wave patterns after care.
Next time someone asks, “What does a chiropractic adjustment do?”, you can say this:
It helps your nervous system work better, improving how your brain and body talk to each other.
And that’s a whole lot more interesting than just “cracking backs,” right?
Want to Go Deeper Into the Science?
If you’re curious to explore the neuroscience behind chiropractic care in more detail, Dr. Heidi Haavik has made her research incredibly accessible for both Chiropractors and the public. Her work dives deep into how chiropractic adjustments influence brain function, neuroplasticity, and nervous system regulation.
👉 For more information, visit:
www.heidihaavik.com
It’s a great resource if you’re the kind of person who likes to know why something works, not just that it does.