Why Do Muscles Pop During Massage? (The Real Reasons)

Whether you’re still going to school, straight out of college, or have been putting in the 9 – 5 grind for many years, a massage can truly help you relax, rejuvenate the muscles and nutrients in your body.

If you’ve ever experienced a massage, you’re probably have wondered at some point:

Why do muscles pop during massage?

Your muscles pop during a massage when your massage therapist kneads and stretches the moveable or ‘synovial joints’ around muscles in your back and shoulders.

How Many Joints in the Body?  

To better understand why your muscles pop during a massage, you should be aware of the different types of joints in the human body, because not all of them cause the popping or cracking sound.

There are three types of joints in the human body— Synarthroses (immovable), Amphiarthroses (slightly movable), and Diarthroses aka Synovial (freely movable).

The first two types of joints— Synarthroses (immovable) and Amphiarthroses (slightly movable) are permanently fixed in place, and are semi-fixed joints respectively.

These two types of joints are not the cause of muscles popping during massage, but it’s the third— Synovial (moveable) joints.

You probably already know where most of these joints are, and pop them often too such as the knuckles of your fingers.

Why Do Muscles Pop During Massage?

Also known as joint fluid, Synovial fluid is a thick liquid located between your joints, and is tasked with lubricating your joints, and allowing for ease of movement.

Synovial fluid contains the gases oxygen, carbon dioxide, and nitrogen, and the pop you hear during a massage is when your massage therapist stretches the joint capsule.

When you knead these joints beyond their natural state, the cavity stretches resulting in a change in pressure and volume, causing gas bubbles to form and pop.

So, the pop you hear when you crack your knuckles is simply a bubble of gas forming and then bursting.

Try cracking the same knuckle again right after! Notice that there’s no popping sound? This is because you now have to wait until the gases are replenished in the Synovial fluid to crack the same knuckle again.

Why Does Popping of Muscles During Massage Feel So Good?  

Your muscles are working continuously throughout the day, causing them to tire and tighten.

This can cause the ligaments and joints surrounding the muscles to feel tense too. Take for example when you crack your knuckles, you are actually stretching your muscles and joints in that area, and relieving the built-up pressure.

A professional massage therapist does the same when he/she massages your back and shoulders to release the built-up pressure.

The resulting pop may be worrying for a few people, but it is indeed completely safe if done properly, and needless to say very satisfying.

Some massages like deep tissue massage may even hurt a little, we talk more about why massages hurt in this article.

Is the Popping of Muscles During Massage Bad for You?

Popping of your muscles during a massage is completely safe, but it’s worth mentioning that too much popping may not be good for you. However, too much popping or intense pain after popping may be a reason for concern.

Final Thoughts

Your muscles pop during a massage due to the release of gases in the Synovial fluid running near your muscles.

It is completely normal for your muscles to pop during a massage, and often times is the reason you experience great relief from sore muscles.

If you don’t hear any popping of muscles during a massage, it doesn’t imply the massage wasn’t worth it, but simply means that you weren’t that sore to begin with!

However, if you feel excruciating pain after a massage, regardless of whether your muscles have popped or not, it is best to get in touch with a medical practitioner immediately.  

An avid yoga practitioner, massage enthusiast, and wellness advocate since 2008. From then on, she has helped countless people alleviate muscle pains, tension and stress, to ultimately achieve wellness and balance in life.