3 stretches to relieve knee pain

Chronic knee pain often has obvious causes, like arthritis or an old injury. Another culprit is stealthier: tight leg muscles that can contribute to knee discomfort. Fortunately, stretching the muscles can help provide some relief.

What's the connection?

Muscles that support the knee (primarily in the legs and hips) need a certain amount of elasticity to work properly. That "give" allows the joints to move through their range of motion easily.

If muscles are tight, they won't stretch as well. "Like a stiff rubber band that's tough to pull, it takes more force to extend tight muscles. That puts extra pressure on the tendons attaching the muscles to bone, which can lead to pain," says Jim Zachazewski, a physical therapist and athletic trainer with Mass General Brigham Sports Medicine.

For example, if the quadriceps muscles in the thighs are tight, they might pull too hard on the tendon at the kneecap, causing inflammation (tendinitis) and a sore knee.

Strength matters

Besides being flexible, leg muscles must be strong to keep the hips, knees, and ankles aligned. "For example, weak hip and leg muscles can prevent the kneecap from gliding smoothly on its track, which can be painful," Zachazewski says.

Strong leg muscles also absorb and reduce the stress you place on the knees with each step. You should do exercises to strengthen your muscles at least twice a week.

Your stretching prescription

If you suspect you have a knee or leg muscle injury, talk to your doctor before stretching. If you get the all-clear, Zachazewski recommends two types of stretching.

Before your daily workout, do some dynamic stretching to prepare the muscles. All it takes is walking or marching in place for a few minutes, gradually increasing your pace or intensity. After your workout, when muscles are warmed up and ready for change, do some static stretching to make muscles longer and more flexible. Hold each stretch for at least 30 seconds.

While you should stretch all major muscle groups, focus on the hip and leg muscles to ease knee pain. We've included examples below, and you'll find more in the Harvard Special Health Report Stretching.

Zachazewski says stretching tight muscles should make them more flexible within three weeks, easing knee discomfort. Leg stretches might also ease an achy knee in the moment of a flare-up. If knee pain isn't going away, it's time to call your doctor.

Moves of the month: Stretching exercises

Calf stretch

Stand up straight and hold the back of a chair for support. Extend your right leg straight back and press the heel against the floor. Allow your left knee to bend while keeping that heel on the floor. Feel the stretch in the back of your lower right leg. Return to the starting position. Repeat with your left leg.

Hamstring stretch

Extend your left leg straight in front of you, heel on the floor and toes pointing up. Place your hands on your thighs for support. Hinge forward from the hip, with your back straight. Bend your right knee and lower your buttocks. Feel the stretch in the back of your left thigh. Return to the starting position. Repeat with the other leg.

Quad stretch

Stand up straight, feet together, holding the back of a chair. Bend your right knee and reach back with your right hand to grasp your foot, lifting it toward your right buttock. Feel the stretch in the front of your thigh. Slowly lower your foot to the floor. Repeat the stretch with your left leg.

Exercise photos by Michael Carroll