Cartilage is a flexible structure that cushions your joints so that the bones don't rub together. Knee cartilage can become damaged in different ways. One type of knee cartilage injury is a torn meniscus.
The meniscus is a large piece of cartilage that is attached to your knee's ligaments, as explained by Sports Injury Clinic. Another form of knee cartilage damage is the wearing away of the substance that occurs when you have osteoarthritis.
While you can't directly strengthen knee cartilage, exercises can help you regain range of motion and strength, although surgery might be needed for significant injury, according to the American Academy of Orthopaedic Surgeons.
For best results, consult a physical therapist for individualized knee cartilage damage exercises.
1. Flex and Extend
Knee cartilage injuries can create swelling around the joint, which can limit your range of motion. Flex and extend exercises can both control the swelling and help you regain full mobility of the joint over time.
- Sit down on a chair — if your feet touch the ground when you're sitting, lift up your leg so that your foot won't touch.
- Bend your knee as much as you can, gently, and then extend your leg to its fullest to complete one repetition. Ease up on either movement if you experience pain.
- Work yourself up to three sets of between 10 and 20 repetitions each day as your pain subsides.
2. Heel Slide
Heel slides help strengthen the muscles in your thighs, as well as strengthen your knee after a cartilage injury. Over time, you'll be able to add resistance to this exercise by performing it either on a carpeted floor or a wood floor with bare feet,
Immediately following your injury, take the path of least resistance as you're healing and wear a sock so your heel will glide on a bare floor more easily.
- Lie down on the floor with your knee bent and your foot firmly planted on the floor.
- Slide your heel toward your buttocks as much as you can without feeling pain in your knee. Work slowly and fluidly to avoid pain.
- Gradually increase the number of repetitions you perform, but also keep trying to move your heel closer to your body to help your knee regain full range of motion.
3. Immobile Extension
Torn cartilage in your knee may cause you to be unable to straighten out your leg completely. An exercise that you actually do while keeping your leg still can help you gradually increase your extension.
- Sit in a chair and place a low stool far enough away from the chair so that your heel can rest on it comfortably while you sit in your chair.
- Put a rolled-up hand towel underneath your heel and let your leg rest, holding it as straight as possible.
You may only be able to tolerate the immobile extension for a few minutes at a time at first, but work your way up to 15 minutes.
4. Calf Stretches
Calf stretches are important knee cartilage damage exercises to incorporate into your knee rehabilitation, as demonstrated by the American Council on Exercise.
- Stand with both feet facing a wall, taking a step back so that you are about an arm's distance from the wall.
- Take one step back with your injured leg. Bend your front leg and keep your back leg as straight as you can. You'll feel the stretch in your front calf, as well as a pull in your back knee.
- Hold the position up to 30 seconds at a time, but release beforehand if your knee begins to hurt.