Cracking and Popping and Clicking – Oh My!

Cracking and Popping and Clicking – Oh My!

For many people this is a daily event. Their joints crack, pop, and click. We crack our knuckles, back, and other joints. We’ll also look at the similar problem of snapping tissues as well.

First let us separate two different phenomena. Cracking and popping are the same issue, but clicking is a fundamentally different issue. We will examine these in turn.

There are many causes for how they arise. Thus, by looking at how they arise we can evaluate the situation if there is a need for proactive prehabilitative protocol.


Joint cracking & popping

First, the theory on how joints pop and crack is due to cavitation. When the joint is ‘cracked’ the volume within the joint capsule is increased through stretching. When this occurs, the pressure drops within the synovial fluid which causes the small amounts of air dissolved within the fluid to come together and form bubbles. They then collapse on themselves. The formation of these bubble and collapse via cavitation causes the popping/cracking sound.

There are various studies on the subject (1), (2), (3), (4), (5), (6), (7). There was also a 50 year case study done.

One of the studies above showed that the forces involved with the joint manipulation may have forces that exceed the force needed for articular damage. However, as a whole the evidence points to no increases in arthritis.

One of the studies also indicated that knuckle cracking increases the preponderance for joint swelling and grip strength loss as well as other traits such as manual labor, biting of the nails, smoking, and drinking alcohol. However, none of the other studies concluded this. There may be some logic to this in that people with overall bad habits and lots of stress may have increased cortisol production and the accompanying negative effects such as poorer recovery. However, I would not worry about it too much.

The swelling and loss of grip strength is particularly interesting though. Everyone has different genes for how tight the articular capsules of their joints are. If you have joints that are particularly lax (meaning “double jointed” in laymans terms), it may not be a good idea to crack your knuckles.

Lax joints are associated with increases in orthopedic injuries and lower strength. Since the joints themselves are a bit more unstable because of the looseness of the connective tissue, the body cannot generate as much force lest it injure itself. Therefore, potentially increasing this joint laxity may be a problem.

This is common in sports with excessive flexibility work such as rhythmic gymnastics where the articular joint capsules can be stretched out significantly. As a precautionary measure if you have looser joints I would avoid cracking them just in case it may present problems down the line. This is especially true if you notice that your joints are being “stretched out” so that they can move further and further each time you crack them.

Obviously, laxity in joints can be compensated with proper strength work to an extent so such things are always beneficial as well.

Finally, crepitus can be present where there is degeneration in the joint, and it cracks inadvertently. If you suspect you have something similar, it’s obviously best not to crack them more than they are.


Joint clicking

The common answer to joint clicking is that if it is painless it is fine. I agree with this assessment especially if you have always had it.

For example, people with more lax joints as described above may have always had issues with clicking albeit not painful clicking. This is fine. The general solution with lax joints and clicking in the knees, hips, elbows, and shoulders is proper strength work. Keeping the joints strong and balanced with proper biomechanical movement will stave off potential injuries.

However, if you have not always had joint clicking, and it is acute onset from particular sports, weightlifting, or other activities I would reexamine the activity to ensure that the clicking may not devolve into something insidious.

In most cases, injuries can be boiled down to issues of

  • Posture
  • Biomechanics
  • Mobility
  • Muscle balance/tension relationships

When these aspects are compromised especially the limbs – ankles, knees, hips, wrists, elbows, shoulders – there is potential for clicking and popping to begin and potentially become malicious.

Let’s look at the knees for a specific example since it is the most common source of clicking (shoulder coming in at a close second). In particular the knee is special in that it has two extra pieces of articular cartilage, the menisci, in between the femur and tibia clicking is fairly common in many cases. It is not always insidious however.

In most cases the neural factors of posture and movement biomechanics contribute heavily to the deficiencies that develop in mobility and many muscle imbalances that arise. It is the development of such imbalances or limitations in mobility that have the potential to cause clicking within the knee to devolve into painful wear on the cartilage.

For example, we discuss in Shoes, Sitting, and Lower Body Dysfunctions that there is often the development of a very quad dominant and very hamstring weak individual.

Such imbalances give rise to problems with the articulation of the joint itself. When synovial joints move against each other they must simultaneously glide and roll to function correctly.


image from moon.ouhsc.edu – See here for more details

When mobility is limited by tight muscles and there are imbalances within antagonistic muscles, the biomechanics of the movement degrade.

Particularly with the knee if the hamstring do not engage correctly during walking or squatting motions, there is likely an excessive anterior glide of the femur on the tibia. This places a much larger torque on the patellofemoral complex. This is bad for multiple reasons:

  • Excessive anterior gliding of the femur may start to impinge the anterior portions of both the medial and lateral menisci which cause clicking. This wears down the meniscus and articular cartilage faster contributing to osteoarthritis.
  • Excessive anterior gliding of the femur puts more strain on the ligaments such as the ACL.
  • The increased torque on the patellofemoral complex causes the quads to become much more active thus aggravating the imbalance of the quadriceps:hamstring strength ratio.
  • The increased torque on the patellofemoral complex may lead to chondromalacia patellae or patellofemoral syndrome or other problems.

These problems are not just manifestations of the whole knee complex. Weakness and decreased mobility at the ankles and hips may also contribute to dysfunctions at the knee. Same with the shoulder, elbows, and wrists.

This is why teaching proper posture and biomechanics while improving mobility and imbalances is so important. For example, we can use box squatting — focusing on sitting back properly to engage the hamstrings and glutes — to help negate quad dominance. This occurs because sitting back shifts the weight distribution of the squat towards the heels will keep the shins upright thus decreasing the torque on the patellofemoral complex and the engagement of the hamstrings will help negate excessive anterior gliding of the femur. This should make the knee joint function properly, and it teaches perfect movement.

Earlier I listed the shoulder as the second most common site of clicking. While it does not have two extra pieces of cartilage as the knee, it has the most mobility and range of motion as any of the joints in the body. Thus, it is very easily destabilized by problems with posture, biomechanics, mobility and muscle imbalances.

In conclusion, if you know you are having onset clicking issues and you notice that you have problems with posture, biomechanics, mobility and muscle imbalances you may have an insidious onset of clicking that may devolve into worse problems.

In many cases correct the imbalances with proper strength and mobility work should improve the condition significant and even eliminating cartilage clicking. This may be the case even in people that have had clicking all their lives from loose joints.


Snapping sounds

If you have tissue that is rubbing and snapping over tissue. This signifies an injury condition.

This occurs in issues such as IT band snapping syndrome and triceps snapping syndrome along with other problems such as nerve and tendon snapping/popping.

In all of these cases, there is likely some problems related to posture, biomechanical, mobility and muscle imbalances. This is not unlike the clicking scenario.

The “quick” fix to eliminate the pain and snapping quickly is to loose up the tissues with soft tissue massage and anti-inflammatory drugs. However, to eliminate the problem entirely all of the factors that contribute to their development from the four attributes (posture, biomechanics, mobility and muscle imbalances) must be examined and corrected.

If you have no idea how to correctly evaluate yourself and perform correct soft tissue work after reading all of my articles then go see a health professional.


In conclusion

1. Joint cracking and popping does not cause increased incidence of arthritis.

2. If you have lax joints, however, you may want to avoid this just in case it may present problems later due to destabilization of the joint and also focus on increasing strength of the muscle/tendons that connect there. This is especially true if you notice the laxity is increasing over time.

3. Clicking without pain is in general fine, especially if it has been there all of the time.

4. Sometimes insidious onset of clicking may devolve into potential problems later on. Correct assessment of posture, biomechanics, mobility and muscle imbalances should be initiated through proper strength, mobility, and soft tissue work.

5. Snapping signifies injury conditions. Like clicking proper care must be undertaken.

I hope this has been helpful to people wondering whether they potentially had problems on their hands or not and the correct decisions to make regarding their health.

Did you like this article? Check out these related articles:

  1. Understanding the Foot and Hip’s Role in Knee Pain
  2. The Dreaded ACL Tear – Rehab Protocols from JOSPT and Solutions for Coaches and Trainers
  3. So, You Hurt Your Lower Back
  4. Understanding Pain When Dealing With Injuries
  5. On Tendonitis

About the Author

Steven Low, author of Overcoming Gravity: A Systematic Approach to Gymnastics and Bodyweight Strength, is a former gymnast who, in recent years, has been heavily involved in the gymnastics performance troupe, Gymkana. Steven has a B.S. in Biochemistry from the University of Maryland College Park, and his Doctorate of Physical Therapy from the University of Maryland Baltimore. Steven is a Senior PCC for Dragon Door's Progressive Calisthenics Certification. He has also spent thousands of hours independently researching the scientific foundations of health, fitness and nutrition and is able to provide many insights into practical care for injuries. His training is varied and intense with a focus on gymnastics, parkour, rock climbing, and sprinting. He currently resides in his home state of Maryland.