The Cracking & Popping Sound of Your Joints: Harmless Habits or Warning Signs?

The human body makes biological sounds all the time. It makes a continuous series of sounds—click, pop, and crunch—from the joints, notably the knuckles and knees. One benefit of these sounds is that they are somewhat interesting and sometimes concerning. Most of us are familiar with the sound of cracking our knuckles, although the crunching sounds that one hears coming from the knees during activity can make one question what’s going on within the knees. The sounds may leave one at a loss. Are you concerned about joint issues, or are you just unlucky enough to have strange anatomy sounds that won’t harm your body?

Why Do Knuckles Crack? Unveiling the Mechanism of the Pop in Depth

The act of deliberately using the fingers to create the characteristic popping noise (often referred to as cracking knuckles) is a habit that a large percentage of the population partakes in. For some, it is simply a nervous tic, and for others, it is a perceived relief or sense of satisfaction. Despite this commonality, cracking knuckles has long been a source of controversy, with people’s concerns about potential long-term negative effects often taking precedence.

The sound made when cracking a knuckle is thought to be caused by tiny gas bubbles forming and collapsing in the synovial fluid, a thick fluid that lubricates joints, protects against friction, and nourishes the cartilage. When a finger is bent or stretched, the amount of pressure in the fluid lowers, and the dissolved gasses become less soluble and form microscopic bubbles. This process is known as cavitation. These gas bubbles are unstable, and their collapse or explosion creates the sound associated with cracking a knuckle. Recently, a new study utilized real-time MRI technology to look at fingers while they were being manipulated and pulled apart and noted that the majority of the time it was not the formation of the gas bubble that created the sound but rather a separate mechanism entirely.

This other mechanism appeared to be the separation of the joint surfaces in such a way that a low-pressure cavity formed that then rapidly collapsed, resulting in the audible “pop.” In this case, the formation of the gas bubble was a byproduct of the joint surfaces separating, not the mechanism that caused the audible sound. There is also a refractory period of about 20 minutes during which it is believed that some of the dissolved gas in the fluid re-dissolves back into the synovial fluid, or some other mechanism allows the joint surfaces to return to their pre-separation state.

Is Cracking Knuckles Harmful? Separating Fact from Fiction

The most common worry about cracking knuckles is whether or not cracking the knuckles causes long-term damage to joints; specifically, does it cause arthritis? There have been a number of studies looking at this issue, and while there are many differing opinions, the overwhelming majority of scientific evidence does not support that habitual knuckle cracking increases one’s risk of developing osteoarthritis.

Cracking Knuckles Side Effects: Beyond the Myth of Arthritis

While there does not seem to be a lot to fear from causing arthritis, there are a few other, less damaging, cracking knuckles side effects for people who tend to crack their knuckles all the time, including

• Social Annoyance: This noise may be annoying or distracting to those around.
• Possibility of Ligament Laxity: Some anecdotal reports indicate that some people tend to experience somewhat increased ligament laxity from not just cracking their knuckles but on occasions forcefully at high repetitions and with time.
• Soft Tissue Injury (Rare): In some very rare cases, if a person forcefully manipulates their joints (from forceful knuckle cracking), they might cause a very minor soft tissue injury. However, this would be very different from commonly cracking the knuckles.

Does Cracking Knuckles Cause Damage?

According to scientific literature, cracking knuckles is not a significant or permanent threat to joints for almost everyone, and the sound is caused by mechanisms that occur in the synovial fluid and the joint capsule. Some habitual knuckle crackers may show minor, relatively non-progressive soft tissue changes, but evidence does not support a relationship with degenerative conditions such as arthritis.

The Knee Joint’s Audible Repertoire: Pops, Clicks, and the Worrying Crunch

In contrast to the deliberate action of cracking knuckles, sounds generated by the knee joint are often unintentional and may be harmless or suggest a problem in some cases. It is important to identify the different types of knee cracking sounds and how they might have arisen to assess the need for worry and medical consultation.

Knee Joint Cracking Sound and Knees Popping Sound: Common and Often Harmless

A problem that many people have experienced is a knee joint cracking sound, or a knee popping sound, during movement such as standing up, squatting, or climbing stairs. These sounds are usually painless and not a cause for concern. There are several possible contributors toward the ease of these benign sounds:

• Movement of the Tendons and Ligaments: As the knee joint moves around, the tendons (which connect muscle to bone) and ligaments (which connect bone to bone) can snap or glide over bony protrusions, which can produce a clicking or popping sound.
• Slight Misalignment of the Knee Joint : Temporary, slight misalignments within the joint may occasionally make a pop or click as the joint realigns.
• Nitrogen Bubbles in the Synovial Fluid : Similar to the mechanism in knuckle joints, the appearance of small nitrogen gas bubbles in the synovial fluid surrounding the knee can also induce popping or cracking sounds—this phenomenon is known as cavitation.

The occasional, painless knee cracking or popping knee sounds are considered normal and nothing to be concerned about!

Crunching Sound in Knee: A Potential Cause for Concern

Compared to the isolated pops and clicks, a crunching sound in the knee, often called crepitus, can be more suggestive that there are underlying irregularities to the surfaces of the knee joint. Crepitus is a grating, grinding, or crackling feeling and sound that occur when the cartilage surfaces rub together in the knee joint.

A crunching sound in the knee, especially if associated with pain, is concerning and may be a sign of:

• Osteoarthritis: This is by far the most common cause of crepitus within the knee and involves the gradual, progressive breakdown and loss of smooth cartilage that cushions the bones in the joint. As the smooth cartilage wears away, the rough surfaces of bone can rub together, creating the crunching sound, and may be associated with pain, stiffness, and swelling.
• Patellofemoral Syndrome (Runner’s Knee): This involves pain at or around the kneecap (patella) and is sometimes associated with some grinding or crunching feeling when the patella moves over the femur (thigh bone).
• Meniscal Tears: When a meniscus is torn, the normal C-shaped cartilage pads that absorb shock in the knee can sometimes cause clicking and/or popping, or even a crunching feeling/sound, especially if a piece of the torn meniscus is getting caught in the joint.
• Chondromalacia Patellae: This condition consists of the softening and breakdown of cartilage beneath the kneecap, resulting in pain and sometimes a grinding or crunching sensation.

How to Get Rid of Crunching Sound in Knee: Addressing the Underlying Issue

The best way to treat or to get rid of the crunching sound in the knee depends on the individual cause. If the crunching occurs infrequently or is otherwise painless, no specific treatment needs to be undertaken. However, if the crunching sound in the knee is accompanied by pain or other symptoms like stiffness, swelling, or reduced range of motion, then it is important to get an assessment by a medical doctor.

Ways to treat the crunching sound in the knee include

Conservative Treatment:

• Rest: Avoid the activities that increase the knee pain and crunching.
• Ice: Use ice packs up to four times per day on the painful and swollen knee.
• Compression: Putting the knee in a brace or using a knee compression sleeve can support your joint and provide mild compression to reduce swelling.
• Elevation: Elevating the leg can help reduce swelling.
• Pain Medication: Medication is not always the solution, but appropriate over-the-counter pain relievers like ibuprofen or naproxen can help relieve knee pain and inflammation.
• Physical Therapy: Performing therapeutic exercise to strengthen the muscles surrounding the knee (quadriceps, hamstrings, and calves), improve their flexibility, and increase stability of the joint.
• Weight Management: Reducing the weight may take the stress off the knee joints.
• Activity Modification: Avoid high-impact activities that lead to the crunching and/or knee problems.
• Injections: If there is inflammation and pain that is not responding to conservative treatments, the doctor may suggest a corticosteroid injection for inflammation and pain relief, in addition to a hyaluronic acid injection to lubricate the knee joint to facilitate movement.

Surgical Relief: If the other options do not help, surgery may be needed in the following situations:

• Meniscal Repair or Removal: In cases of significant meniscal tears that continue to bother the patient.
• Arthroscopic Debridement: In order to smooth out a rough surface of cartilage or loose fragment in cases of osteoarthritis or other conditions.
• Knee Replacement Surgery: In advanced osteoarthritis with debilitating pain and limitations in the knee.

When to Seek a Doctor’s Appointment?

While generally considered harmless and not linked to arthritis, one should see a doctor for cracking knuckles and popping knees if experiencing any of the following:

• Pain
• Swelling
• Reduced Grip Strength or Function
• Deformity or Change in Joint Appearance
• Accidental Injury
• Locking or Catching
• Instability or “Giving Way”
• Limited Range of Motion
• Warmth or Redness
• Loud Pop with Immediate Pain and Swelling (especially after an injury)
• Persistent or worsening symptoms along with fever and sickness

Immediate medical attention from an orthopedic specialist can help reduce the severity of a condition and provide relief.

Conclusion

The sounds originating from our knuckles and knees expose the many moving parts within the joints and the processes taking place. Normal immediate pops and clicks are harmless; nevertheless, persistent sounds of crunching, especially if painful or symptomatic, warrant further investigation. These sound-producing mechanisms expose our joints for us to consider new ways of thinking about identifying issues versus quirks. Overall, with an awareness of sound structures and accompanying symptoms, one can make proactive decisions about joint health and well-being.

Yashoda Hospitals in Hyderabad is a leading healthcare provider with expertise in addressing orthopedic and joint-related issues. We have comprehensive orthopedics and joint replacement departments in Secunderabad, Somajiguda, Malakpet, and Hitec City, staffed by experienced orthopedic surgeons, sports medicine specialists, and rehabilitation experts. We offer advanced diagnostic services to identify joint sounds and abnormalities, ranging from common conditions like osteoarthritis to less frequent issues affecting hand and wrist joints. Treatment approaches include conservative management with medication, physiotherapy, and pain management injections, as well as state-of-the-art surgical interventions like arthroscopy and robotic-assisted knee replacement. Our multidisciplinary approach ensures holistic care, aiming to alleviate pain, restore mobility, and improve overall joint health.

Have any questions or concerns about your health? We’re here to help! Call us at +918065906165 for expert advice and support.