Squats are one of the most effective resistance-training exercises you can do. It’s an exercise that works your quadriceps, hamstrings, glutes, and core while burning more calories than other resistance exercises. Squats burn calories and create a favorable hormonal environment for building lean body mass. What workout would be complete without squats? Some people are concerned when they squat and hear sounds coming from their knees – cracks, crackles, and pops. What are those sounds coming from your knees when you descend or ascend from a squatting position? Should you be concerned if you have noisy knees?
Knee Cracks and Pops
Knees that make cracking and crackling sounds are pretty common. Your knee joints are constructed of three bones – the femur, or thigh bone, the tibia, or shin bone and the patella or kneecap. A layer of cartilage covers the bones and allows them to move smoothly against one another when you squat or bend your knees. Unfortunately, sometimes the cartilage thins down in certain areas. When thinner areas rub against each other, it makes a cracking noise due to friction. Plus, perfectly normal ligaments, the tissue that connects the bones to each other and stabilizes the knee, can make a noise when you bend your knees as the ligament rubs against a bony prominence.
Another sound you might hear when you squat or lunge is a popping sound. Pops often come from a change in joint pressure. When pressure changes take place, carbon dioxide, dissolved in the synovial fluid that bathes the knee joint, can come out of solution and form a bubble. When the bubble bursts you may hear a pop.
Deciphering Knee Noises
Should you be concerned about knee cracks and pops? In most cases, those annoying sounds are of little clinical importance. People with healthy knees can hear these sounds too. When you should be concerned is when your knee makes noise AND you have pain, a sensation that your knee is “catching” or knee swelling. These may be signs of significant cartilage loss in the knee due to knee osteoarthritis. In some cases, the cartilage can become loose and irritate the soft tissue, causing pain and a grinding sound when you squat or bend the knee.
If you have popping and knee pain, a catching sensation or your knee is giving way, you could have a torn meniscus. Menisci are on both sides of your knees and are moon-shaped pieces of cartilage that help absorb force. If you place your hand over your knee as you extend your leg and feel popping or crunching or you have knee pain when you climb stairs, you may have a condition called chondromalacia, sometimes referred to as runner’s knee. Chondromalacia is damage to the cartilage in the knee and comes from overuse.
If you’re experiencing knee pain, swelling, your knee is giving way, catching or locking up, take notice. Assuming you’re using proper form, you shouldn’t experience pain when you do squats. The same goes for lunges. If it does hurt to do these exercises or you have other knee symptoms, stop doing squats and get your knees checked out. Repetitive movements like squats and lunges can make a damaged knee or knees worse.
Are Squats Bad for Your Knees?
At one time, some experts believed squats increased the risk for a knee injury after some studies in the 1960s suggested squats might be damaging to the knees and contribute to instability. More recent research show squats aren’t linked with knee instability, even with deeper squat depths that go below parallel. In fact, animal studies show squats increase the strength of the ligaments in the knees that help keep the knees stable. Doing knee squats may actually protect against injury by strengthening these ligaments.
Even if you have healthy knees, make form a priority when you do squats. Before doing a squat, warm up to get the blood flowing and your core body temperature up to reduce the risk for injury. When you’re starting out, use no resistance until you’ve mastered the movement and can do it with perfect form. When you use sloppy form, you DO put yourself at risk for knee and back injury. Plus, you won’t get the full benefits of the exercise
Enjoy the Benefits of a Squat
Few resistance exercises work as many muscle groups as squats. Squats are a compound exercise that works multiple muscle groups including the muscles in your lower body and your core. When you do them you’re not only reshaping the muscles in your core and lower body (including your glutes), you’re building functional strength as well. Think how many times you squat down to pick something up every day. Squats give you the strength and power to do it effortlessly. Because they use so many muscle groups, they also have an anabolic effect and boost hormones that help you build muscle and burn fat. There’s a reason squats are sometimes called “the king of exercises.” If you don’t have active knee issues, doing squats and squat variations can greatly boost your lower body strength and improve body composition.
The Bottom Line?
Most of those cracking and crackling sounds you hear when you squat aren’t a sign of serious knee pathology. Most people experience some of these sounds as they get older. On the other hand, if you have noisy knees and other knee symptoms, especially swelling, locking or the knee is giving way, stop doing squats and see a health professional.
The good news? Squats are a highly effective exercise and one that helps you build stronger knees that are more resistant to injury.
WebMD. “What Is Your Knee Telling You?”
American College of Sports Medicine. “Safety of the Squat Exercise”
J Assoc Phys Ment Rehabil. 15; Pp 6-11. 1961.
Med Sci Sports Exerc. 1989 Jun;21(3):299-303.
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When Your Knees “Crack” and “Pop” What Does It Mean?
Squats May be the King of All Exercises, But Are They a Safe Exercise for Your Joints?
Knee Noises: Should You Be Concerned if Your Knees Crackle or Pop When You Exercise?