Clickety clack goes the… 

Dancer’s knee.

Whether it is the changing weather, one too many rehearsals, or perhaps just good, old-fashioned fatigue, clicking, grinding, and popping in the knee joint are all very common sensations for dancers. Usually, these sensations are not accompanied by pain, and just remain one of the many weird things that accompany the dancer’s body. If you are reading this because you experience these sensations but you also frequently experience pain with them, then please see a medical provider! Otherwise, if you are just looking to understand the “music” produced by your knees, you’re in the right place.

There are a couple reasons for why you might have knees that make noise, and we’ll explore some of those common causes here.

Harmless Popping 

Most of us, even if we are not dancers, have experienced other joints that pop– your knuckles, for example, or maybe your back. This kind of popping is harmless, and is the result of very small bubbles of nitrogen. Our joints contain a thick fluid known as synovial fluid, and the purpose of this substance is to cushion the respective bones forming the joint. In this way, the synovial fluid prevents the bones from wearing down. 

(Interestingly enough, synovial fluid is a non-Newtonian fluid… isn’t that cool?)

The popping that you may experience while cracking the knuckles or stretching the back is the result of those tiny nitrogen bubbles in the synovial fluid popping. When these bubbles pop, it is called “cavitation,” and results in the cracking sound that so many dancers know and love. 

More Serious Popping

One of the most common things that I observed in my time working in a dance injury clinic was the prevalence of IT (iliotibial) band tightness with knee pain. I would approximate that some 90% of dancers who came in with knee pain experienced severe tightness across the IT region when the region was massaged.

Severe pain at the front of the knee as a result of the IT band moving incorrectly is known as Runner’s Knee or Iliotibial Band syndrome. This pain is the result of the IT band “catching” over the lateral condyle of the femur. Let’s recall the anatomy of the knee joint to simplify this:

As the femur moves, the patella “glides” along or articulates with it. The two sides of the femur that “hug” the patella are known as condyles. Can you identify where the condyles are in this diagram?

There are several other causes for the knee making its various sounds– Baker’s cysts, or perhaps loose cartilage bits– but the other issue observed in a significant number of dancers (in my experience) is patellar maltracking. Interestingly, during my research for this post, I discovered that patellar maltracking is much more common in young women… and given that patellar maltracking is something that I have dealt with (and am still dealing with!), that definitely tracks! I hope you caught that joke there…

When it is working optimally, the patella glides smoothly into the groove at the end of the femur (trochlear groove). Most dancers will “pull up” the kneecap to achieve a straight line while dancing. Under normal conditions, the patella should glide upwards in a straight motion. In cases of patellar maltracking, the kneecap will shift towards the outside or inside first, and then glide into the trochlear groove. In very, very severe cases, the patella can completely dislocate– but chances are that if your patella is completely dislocated, you are not stopping to read this article and instead are heading to the hospital.

So how can you assess this? If you are having pain and some swelling at the front of the knee along with some clicking/popping/grinding, then you may want to assess for any maltracking. Sit on the floor with your legs extended in front of you. Tighten the rectus femoris (quad) muscle and slide the patella upwards into an active position. Observe the movement of your patella as it glides upwards. Is it shifting to one side first, or traveling upwards in a straight motion?

Once you assess where your pain and motion is at, you have a much better idea of what type of medical care or physical therapy you need. As always, see a medical provider for cases of prolonged and severe pain– but it doesn’t hurt at all to have an idea of why you’re feeling the way that you’re feeling. Education is empowerment– even when it comes to creaky knees.

Dear readers, I will see you soon with another installment on the knee– this time, discussing the aging knee, and the exercises you can keep doing to stay healthy and pain-free while dancing. Until then!