There are a lot of great things that come out of regular exercise, but an overuse injury involving a tendon isn’t one of them. Almost by definition, it seems to happen at the worst time — when you’re using a certain joint or muscle a lot, which tends to be specifically in preparation for a big race or athletic event.

You've probably experienced — either first-hand or known someone who has — Achilles tendonitis, or jumper’s knee (patellar tendonitis), when you’ve been pumping up your run intensity or duration. Or maybe you're familiar with golfer’s elbow, thanks to overloading the forearm tendons with all of the grabbing, pulling, climbing, and carrying that goes on in obstacle course training.

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And to no surprise, these things hurt. Acute tendonitis comes with sharp pain and inflammation at the place where the tendon attaches to the bone that gets worse when you move it, while chronic tendonitis is a more dull but constant pain.

The standard treatment for a tendon injury is a good-old fashioned dose of RICE: rest, ice, compression, and elevation. But if that’s not doing the trick (especially if you’ve had persistent pain that’s continued beyond three months), it might be time to add cross-fiber friction patellar tendonitis massaging to the mix, Joe Tatta, PT, DPT, CNS, creator of the Integrative Pain Science Institute and author of Heal Your Pain Now, suggests. Here’s what you need to know.

How to Do a Cross-Fiber Friction Patellar Tendonitis Massage

The good news is, you can do a cross-fiber friction massage to target patellar tendonitis and other pain yourself. The not so good news: It’s going to hurt a little. (But actually, that’s a good thing, too.)

“Cross-fiber friction is typically very short, just 3 to 5 minutes, one or two times a day, and preferably after exercise,” Tatta says.

To properly perform a cross-fiber friction massage, use the pads of your fingers to apply solid pressure and rub the affected tendon perpendicular to the length of its fibers. 

“Think of it like strumming strings of a guitar, only harder,” Tatta says. "Just how hard depends on your own perception of the pain. It should be hard enough that it’s unpleasant, but not extremely painful or unbearable.”

If it does become unbearable, stop, or you’ll risk making the injury worse.

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Afterward, you should feel either no change or a little better. If it feels worse, don’t do it again, and see a physical therapist, Tatta suggests. And, of course, don’t attempt a vigorous patellar tendon massage or other cross-fiber friction massage if you suspect that you have a ruptured or infected tendon or a fractured bone.

Why Cross-Fiber Friction Massage Works for Targeting Patellar Tendonitis and Other Types of Pain

In terms of why it works, experts aren’t entirely sure, and there’s not a whole lot of scientific evidence as to how it works yet. Bart Wolbers, researcher and chief science writer at AlexFergus.com — a site that investigates the scientific validity of different health inventions — points to a few promising studies on the benefits of cross-fiber friction.

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One, published in the American Association for Hand Surgery’s journal, Hand, found that the technique helped reduce pain and increase grip strength in people with tennis elbow. And a research review in the Journal of Sport Rehabilitation found it worked for both shoulder and elbow tendon problems, though again, the available research was limited.

“We’re still learning how manual therapy techniques help to lessen or mediate pain, but there are two predominant theories,” Tatta says.

Stimulating Healing on a Cellular Level

The first is that cross-fiber friction is stimulating healing to happen on a cellular level.

“When you injure a tendon, your body won’t replace it with new tendon — it lays down scar tissue in place of that,” Tatta explains. “Cross-fiber friction massage is essentially re-stimulating the inflammation response.”

As a result, your immune system kicks back into gear and goes to work creating new or additional scar tissue to strengthen the tendon.

Creating a Solution Through Self-Stimulated Pain

The second theory is that the pain you’re creating through the friction massage is itself a solution, especially for ailments like patellar tendonitis.

“Pain is often used as a tool for stopping pain,” Tatta says. “This technique is applying pain on top of the tendonitis pain. As a result, the brain pays more attention to the new pain, and puts less emphasis on the old pain.”

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In other words, cross-fiber friction massaging may simply be a distraction method — albeit a very sophisticated one that works on the brain’s prefrontal cortex, amygdala (the emotional center of the brain), and the brain stem and spinal cord.

How to Know if Cross-Fiber Friction Massage Is Working for You 

Some people will feel better right away after a single session, Tatta says. For others, it might take a bit longer. But if it’s not working within two weeks, you’re probably not going to benefit from it. At this point, he recommends seeing a physical therapist.

“You might want to see a physical therapist for things like patellar tendonitis anyway, for at least one session, for more education on your injury and to get an exercise program for recovery,” Tatta explains.

A physical therapist can also help you determine what training errors might have caused the injury in the first place so you can avoid a reinjury in the future. 

“Ultimately, to heal the tendon, you really need to use a progressive exercise schedule that increases the weight load on your tendon every 10 to 14 days as you get stronger,” Tatta says. “Loading of the tendon can help you get it healthy and pain-free, and a PT can help you determine your best schedule for recovery.”