The cartilage between your knee bones, called the meniscus, helps disperse friction and prevents the bones from rubbing against each other. A sudden accident, such as a fall or twist of the knee, can cause this cartilage to tear, called a meniscus tear. Should you injure the meniscus, surgery is almost always necessary to repair it, since it cannot heal on its own. Those with mild to moderate tears may be able to improve knee function and improve healing with gentle, bodyweight exercises, as described below.Quad ExercisesTo improve healing, maintaining or improving the strength of your legs is necessary. As a bonus, it can also prevent future tears. For the quadriceps, the group of muscles above your knee, doing something called quad sets can help strengthen this area.How to do it: Sit on the ground with your injured leg held straight in front of you against the ground. Now slowly straighten your foot until the heel is touching the ground. You should feel the quadriceps tightening. Hold this for about 6 seconds before releasing. This is one repetition.Do 8 to 12 repetitions.Hamstring ExercisesThe quadriceps aren't the only muscles in your upper leg--your hamstrings, the muscles in your back thigh, can also provide leg stabilization. Strengthening the hamstrings and quadriceps equally is necessary to prevent further injury, since they both balance out the leg. Most physicians recommend doing hamstring curls to strengthen this area.How to do it: Lie on your stomach with your knee straight against the ground. Now slowly bend your injured knee until it grazes your buttocks. Slowly lower the knee into the starting position. This is one repetition. Continue doing this for 8 to 12 repetitions.Heel ExercisesThe calf muscle is important for providing additional stabilization to your lower leg. Physicians often recommend a set of exercises for this area: seated and standing heel raises.Seated heel raises: Sit in a chair with your back against the seat. Both knees should be bent in front of you. Now slowly raise your heels until only your toes are touching the ground. Hold for about 6 seconds before returning to to the starting position. This is one repetition. Continue doing this for 8 to 12 repetitions.Standing heel raises: Stand straight with both feet on the ground. If you need additional support, you can hold onto a chair. Now slowly raises both heels off the ground until only your toes are against the ground. Hold this for about six seconds before releasing.Done properly, these exercises should speed up recovery time and help you maintain leg strength, which is crucial for preventing future knee injuries.