Cycling is gentle on the joints – until it’s not. Tease out these common causes of knee strain to keep your hinges pain-free. – By Selene Yeager
If you’re a cyclist who’s ever felt the sharp twinge of “Crap, there’s something wrong!” in one or both of your knees, you’re not alone. Knee pain is the most common lower-body problem among us pedal pushers, with as many as 65 percent of us experiencing it, according to one study.
Most knee pain comes from “overdoing it,” as they say. You ride longer and/or harder than you’re in condition to, which strains your connective tissues, making them inflamed and painful. But what about those spontaneous flare-ups of crank-stopping pain? It might feel like they came out of nowhere, but they’re usually just the first noticeable symptoms of a long-brewing problem: The culprit is generally improper equipment and/or bike position, says England based bike-fit specialist Michael Veal.
“Many cyclists are forever tinkering with their position, looking for that elusive perfect position,” he says. But what feels just right for a few pedal strokes around the block can end up feeling pretty wrong after 100+km of riding. A good bike fit is essential for preventing most causes of knee pain. But before you head to a bike fitter or medical professional, try a little self-diagnosis. Here’s a guide to help you trace what hurts back to the source.
Pain in the front: When your knee hurts right on the kneecap (patella), it’s generally a product of your powerful cycling quads. Your quad muscles attach to the shin via the patella, and when you’re really pumping, they might deliver too much shear force across the joint. Bike-specific issues to check for include saddle height; saddle fore and aft, and/or crank length.
“A saddle that is too low will cause your knee angle to be too tight at the top of the stroke, which increases the shear forces pulling the patella against the femur, which in turn increases the likelihood of tendonitis and harmful stresses in the cartilage behind the kneecap,” says Veal. “Likewise when the cranks are too long for your leg length, the knee joint is also too tight at the top of the stroke.”
How low is too low for a saddle? “For a quick reference to check if your saddle is the right height, have a seat and rest your heel on the pedal with the pedal in the 6 o’clock position,” says fit specialist and physical therapist Sara Bresnick, owner of Pedal Power Training Solutions in Medford, Massachusetts. “The knee of that leg should be straight. That equates to a 20- to 25-degree knee bend when clipped in.”
Riding with your saddle too far forward also can cause knee pain in the front, says Veal. “Your saddle should be positioned so the tibial tuberosity—or bony bit below the kneecap—is above the ball of the foot, which in turn should be above the pedal spindle,” she says.
Also, be mindful of your form. Big-gear mashing, climbing in monster gears, and hard sprinting (especially if you’re not conditioned for it) can put undue stress on the knee and cause this type of pain.
Pain in the back: Pain behind the knee is less common than that in the front, and is generally easier to trace back to a culprit: over-extending the knee, says Bresnick. Your saddle is too high or too far back. “Try lowering the saddle a bit or moving it forward a bit in relation to the handlebars,” she says.
This pain is also more common among cyclists who spend a lot of time on fixed-gear bikes; when you ride fixed, you use your hamstrings to decelerate your pedal stroke, which can put the biceps femoris tendon (a hamstring muscle that runs down the back of your leg toward the outside of your knee) under too much load and irritate it. Giving your legs a break with some freewheeling now and then can help.
Pain on the inside: When you feel pain on the insides of your knees, look down at your feet: Improper cleat placement is often a culprit, says Veal. Your cleat position affects your Q-factor, which dictates how far apart your feet are laterally when pedalling. Ideally the spacing should be such that the loads from your knees to your pedals are travelling vertically without pushing the knee inward or outward, which stresses the collateral ligaments on either side of your knee and can lead to pain. Cleats positioned too close to the insides of your cycling shoes increase the distance between your feet, which can stress the inside collateral ligaments and cause medial (or inside) knee pain.
Too much float in your pedals also can cause medial knee pain. A little float—about 4.5 degrees—is all you need to be comfortable and keep your knees from getting stressed.
Pain on the outside: Pain on the outside of the knee is often caused by iliotibial (IT) band syndrome—a stabbing pain that happens when the IT band (a fibrous connective tissue band that runs from the hip along the thigh to the tibia) becomes stressed and inflamed. “Misaligned cleats that cause the foot to be excessively toed in can cause this,” says Veal. So can cleats that are placed too far to the outsides of the shoes, causing too narrow of a stance on the bike.