Many people wonder if they should be concerned about constant joint cracking. One area where this may occur is the knees; upon bending or straightening the knee, some people experience involuntary cracking. These loud pops can be rather frightening, and some fear structural problems either causing or resulting from the cracking. Is constant knee cracking a cause for concern?
First, let’s consider what normally happens when you crack a joint, such as the knuckles. The bones of the joint move apart, which creates a temporary vacuum (since more volume equals less pressure). Gases that have dissolved in the joint’s protective fluids undergo a reconstitution of sorts when volume decreases; the dissolved gases now form into bubbles. The pop you hear is the sound of these bubbles popping as pressure drops even lower. This process is called cavitation.
The phenomenon of joint cracking has not been well studied, but its commonness and low association with problems has led the medical community to declare it harmless – that is, unless pain accompanies the noise you hear. Painful cracking of joints merits concern and medical assessment. Excessive knee cracking accompanied by pain may indicate one of the following two problems.
A common muscle imbalance occurs between the inner and outer thigh muscles. The quadriceps consist of four muscles in each thigh. If an outer muscle is stronger than an inner, this creates uneven strain on the knee cap (patella). The patella moves over a groove in the thigh bone (femur) when you bend or straighten the knee. Uneven tension from the quadriceps changes the location of the groove in relation to the patella, resulting in pressure, pain and sometimes cracking.
This muscle imbalance is often pronounced in runners; maltracking of the knee cap is sometimes even referred to as runner’s knee. It can also occur in the sedentary, though. A physical therapist trained to detect imbalances can diagnose or rule out this cause of knee pain. See the slideshow at www.fitsugar.com to learn about exercises that build inner thigh strength.
This condition is characterized by degeneration of the cartilage that sits on the underside of the patella. This cartilage is meant to facilitate smooth, painless movement between the patella, femur and shinbone. When it wears, pain, inflammation and cracking can result.
Chondromalacia patella can be caused by the aforementioned muscle imbalance; the misaligned movement of the patella can lead to cartilage wear. It may also be caused by repeated trauma, such as seen in overuse injuries. These are most common in runners, skiers, cyclists and soccer players. This condition can affect young children and teens who play rigorous sports. A final risk factor is congenital abnormality, such as “knock knees.”
General treatments for this condition include ice, anti-inflammatory medication and bracing of the knee. If overuse is an underlying cause, a reduction of activity followed by leg strengthening exercises and careful gradation of activity can be effective. If a muscle imbalance is the underlying cause, it should be addressed through physical therapy to realign the patella.
If you have constant knee cracking, it may indicate a muscle imbalance. If the cracking is accompanied by pain, there is likely a structural problem that requires addressing. Keeping toned and balanced leg muscles is a good way to prevent or correct problems of the knee. Understanding knee cracking causes allows you to know when it’s a cause for concern.