Stiffness in the knees means the loss of range of motion. To prevent stiffness and rehabilitate stiff knees, use a series of range-of-motion exercises. Work at these exercises until you can do these 30 times twice a day. Once the exercises are finished, wrap an ice pack in a washcloth or dishtowel and apply it to your knees.
Sit on the floor with your legs straight out in front of you. Tighten the muscles in your upper thigh and push your knees down into the floor. Do not force them. Each day you do this exercise, your range of motion will increase.
Slight Knee Flexion
Sit on the floor and place a rolled-up towel under your knees. Gently tense your muscles on the top of the thighs and flex your toes back toward you. Hold for 10 seconds and then relax. Do three times.
Passive Knee Flexion
Sit on the floor with your back against the wall. Your legs should be straight out in front of you. Wrap a towel around your heel and pull the knee toward your chest until you feel a stretch. Release the pull and relax. Do this three times and switch legs.
Lie on the floor on your back. Place your arms on the floor beside you. This is not a sit-up, so do not raise your neck and shoulders while doing this exercise. Lock your knee, and raise your leg upward 8 to 10 inches from the floor. Hold position for 10 seconds, then lower your leg. Try to do this three times then switch legs.
Lie on the floor on your stomach. Bend your knee back as far as you can, aiming for the small of your back. Hold for 5 seconds and then relax. Do three times, then switch legs.
Do this exercise in a chair or on the edge of your bed. Sit in a normal position with your back straight and your feet flat on the ground. Push down on your thigh with your hand and straighten your leg at the knee. Start by doing this exercise three times, then switch legs.
To finish this series of exercises, loosen up your knees by sitting in a chair with your feet flat on the floor. Move your feet as close together as you can. Roll your knees as far to the left as you can. Return to the middle starting position, and then roll them to the right. Do this at least three times.