What Is the “Pop” During a Chiropractic Adjustment?
If you've ever had a chiropractic adjustment—or watched one online—you've likely heard the famous “pop” or “crack” sound. It’s a sound that’s often associated with relief and restored movement, but many people wonder: What exactly is that pop during a chiropractic adjustment? Is it bones cracking? Is it dangerous?
Let’s break down the science behind this phenomenon, known as joint cavitation, and what it really means for your spine and overall health.
What Causes the “Pop” in a Chiropractic Adjustment?
The “pop” sound you hear during a chiropractic adjustment isn’t your bones cracking—it's actually gas being released from the joint. This process is called cavitation.
Joints, particularly the synovial joints in your spine, contain a lubricant called synovial fluid. This fluid contains dissolved gases like oxygen, nitrogen, and carbon dioxide. When a chiropractor applies a high-velocity, low-amplitude (HVLA) thrust to a joint, it creates a rapid change in joint pressure. This drop in pressure allows gases in the synovial fluid to form a bubble, which collapses and creates that audible “pop.”
According to a 2022 study published in Chiropractic and Manual Therapies, this phenomenon is mechanical in nature and harmless when performed properly by a trained chiropractor. The sound itself is not necessary for therapeutic benefit, but it often coincides with improved joint movement.
Does the Pop Mean the Adjustment Was Successful?
This is one of the most common misconceptions. While many patients associate the sound with a successful treatment, the presence or absence of a pop is not an indicator of effectiveness.
The same 2022 study concluded that the clinical outcomes of spinal manipulation—like reduced pain and increased mobility—occur regardless of whether cavitation is heard. Chiropractors focus on restoring function and alignment, not just producing noise.
Benefits of Chiropractic Adjustments—With or Without the Pop
Pain Reduction: Adjustments have been shown to reduce pain by stimulating spinal joint receptors and disrupting pain signals.
Improved Range of Motion: Releasing joint restrictions restores natural movement.
Muscle Relaxation: Manipulation affects neuromuscular reflexes, helping to reduce tension.
Psychological Relief: Many patients report feeling immediate relief or satisfaction after hearing the pop—even if it's partly placebo-related.
Is the “Pop” Safe?
Yes, when performed by licensed professionals, cavitation is completely safe. It’s a normal byproduct of joint manipulation. Serious complications are extremely rare and typically involve pre-existing conditions, which chiropractors screen for during patient intake.
Mild soreness may occur after an adjustment, similar to how muscles feel after a workout, but this usually resolves within 24–48 hours.
Final Thoughts: Should You Worry About the Pop?
Absolutely not. The pop during a chiropractic adjustment is a harmless, natural release of gas from a joint under pressure. It’s not bones cracking or anything breaking—it’s simply part of how the body responds to fast, targeted movement.
Whether you hear a pop or not, the real goal of chiropractic care is improved function, less pain, and better quality of life. The sound may be satisfying, but the science tells us that it’s the movement—not the noise—that matters most.
Best,
Your Chiropractor Dr. Kendall