The knee is comprised of:
The tibia (shin)The femur (thigh)The patella (kneecap)
These three bones are supported by many muscles, tendons, and ligaments. Inside the knee are two shock absorbers, each called a meniscus.
Overview
Your knee is a major joint in the body that is responsible for walking, climbing stairs, and rising from a seated position. Pain in the knee can limit one or all of these activities. By keeping the knee joint mobile and strong, problems with knee pain may be avoided and your mobility can be maintained.
Exercises are your main tool in maintaining good strength and mobility in your knees, and some simple exercises that you can do at home can help keep your knees moving right. (After injury or knee surgery, your physical therapist may prescribe exercises similar to these to help you return to normal activity and function.)
Lie on your back with your knee straight. Tighten the muscle on the top of your thigh by pressing the back of your knee into the floor. A small towel can be rolled up and placed underneath your knee for comfort and to give you something to push your knee into. Hold this position for 5 seconds and then relax. Perform 10 repetitions.
While lying on your back, simply slide your heel up the floor so your knee bends. Allow your knee to bend as far as possible, hold for 2 to 3 seconds, and then return to the start position. Perform 10 repetitions.
This exercise is the perfect one to do if you have limited range-of-motion due to osteoarthritis of your knee.
Lie on your back. Place a small bolster underneath your knee. A coffee can, paper towel roll, or rolled up towel will work great. Tighten your quad muscle while straightening your knee out all the way. Your heel should rise up while your knee rests on the bolster. Straighten your knee all the way and squeeze your quad muscle once it is fully straightened. Hold the end position for 3 seconds and then slowly relax. Repeat for 10 repetitions.
Make sure you move in a slow, steady fashion and stop if you feel any knee pain.
While lying on your back, bend one knee and straighten the other. Tighten the muscles on the top of your thigh of the straight knee. While keeping the knee straight, lift your leg up about 12 inches. Hold for 2-3 seconds and then lower slowly. Perform 10 to 15 repetitions.
You can make the straight leg raise exercise more challenging by adding a cuff weight to your thigh or ankle.
You can also perform the straight leg raise while lying on your side to work your glutes or on your stomach to strengthen your back, buttock, and hamstrings muscles.
A Word From Verywell
Remember that healthy knees mean being able to move your knee joint freely and with no pain. By working to keep your knees moving and keeping your muscles strong, you may be able to maximize your knee mobility and prevent injury.