A knee sprain is a joint injury that causes a stretch or tear in one or more of the knee ligaments. A sprain can be mild, moderate, or severe depending on the amount of damage to the ligament.

Ligaments are strong bands of tissue that connect one bone to another. The knee joint is held together by the cruciate and collateral ligaments. These ligaments connect the thigh bone in the upper leg to the bones in the lower leg. The cruciate ligaments cross each other inside the knee joint and work like a hinge. The collateral ligaments are located on either side of the knee and keep the knee stable.

A knee sprain most often occurs while playing sports, but can occur during falling or twisting accidents. Collateral ligaments are usually injured when hit by a force on the side opposite the ligament. The cruciate ligaments can be injured by sudden twisting movements or from being hit directly. 

 What are the symptoms?

         How is it treated?

Treatment includes the following:

• Put an ice pack on your knee for 20 to 30 minutes every 3 to 4 hours for    2 or 3 days or until the pain goes away.

• Keep your knee elevated whenever possible by placing a pillow underneath it until the swelling goes away.
• Take an anti-inflammatory medicine or other drugs prescribed by your health care provider.

After the knee pain goes away, you will probably need to do exercises given to you by your health care provider or physical therapist for many weeks.

Your provider may also recommend that you:

• Wrap an elastic bandage around your knee to keep the swelling from getting worse.
• Use a knee immobilizer initially to protect the knee.
• Use crutches.

If you start participating in sports or other activities before you have completely recovered, you may worsen your injury, which could lead to permanent damage. Everyone recovers from injury at a different rate. Follow your health care provider's instructions and advice. In general, the longer you have symptoms before you start treatment, the longer it will take to get better.

Unfortunately, most knee sprains occur during accidents that are not preventable. However, you may be able to avoid these injuries by having strong thigh and hamstring muscles and maintaining a good leg stretching routine. In activities such as skiing, make sure your ski bindings are set correctly by a trained professional so that your skis will release when you fall.

                         Knee Exercises

Passive knee extension: Do this exercise if you are unable to fully extend your knee. While lying on your back, place a rolled up towel underneath the heel of you injured leg so it is about 6 inches off the ground. Relax your leg muscles and let gravity slowly straighten your knee. You may feel some discomfort while doing this exercise. Try to hold this position for 2 minutes. Repeat 3 times. Do this exercise several times per day. This exercise can also be done while sitting in a chair with your heel on another chair or stool.

• Heel slide: Sit on a firm surface with your legs straight in front of you. Slowly slide the heel of your injured leg toward your buttock by pulling your knee to your chest as you slide. Return to the starting position. Do 3 sets of 10.

•  Straight leg raise: Lie on your back with your legs straight out in front of you. Tighten up the top of your thigh muscle on the injured leg and lift that leg about 8 inches off the floor, keeping the thigh muscle tight throughout. Slowly lower your leg back down to the floor. Do 3 sets of 10.

•  Prone knee bends: Lie on your stomach with your legs straight out behind you. Bend your knee so that your heel comes toward your buttocks. Hold 5 seconds. Relax and return your foot to the floor. Do 3 sets of 10. As this becomes easier you can add weights to your ankle.

• Wall slide: Stand with your back, shoulders, and head against a wall and look straight ahead. Keep your shoulders relaxed and your feet 1 foot away from the wall and a shoulder's width apart. Keeping your head against the wall, slide down the wall, lowering your buttocks toward the floor until your thighs are almost parallel to the floor. Hold this position for 10 seconds. Make sure to tighten the thigh muscles as you slowly slide back up to the starting position. Do 3 sets of 10. Increasing the amount of time you are in the lowered position helps strengthen your quadriceps muscles.

• Step-up: Stand with the foot of your injured leg on a support (like a block of wood) 3 to 5 inches high. Keep your other foot flat on the floor. Shift your weight onto the injured leg and straighten the knee as the uninjured leg comes off the floor. Lower your uninjured leg to the floor slowly. Do 3 sets of 10.

• Knee stabilization: Wrap a piece of elastic tubing around the ankle of your uninjured leg. Tie the tubing to a table or other fixed object.

I.        Stand on your injured leg facing the table and bend your knee slightly, keeping your thigh muscles tight. While maintaining this position, move your uninjured leg straight back behind you. Do 3 sets of 10.

II.       Turn 90° so your injured leg is closest to the table. Move your uninjured leg away from your body. Do 3 sets of 10.

III.     Turn 90° again so your back is to the table. Move your uninjured leg   straight   out in front of you. Do 3 sets of 10.

IV.     Turn your body 90° again so your uninjured leg is closest to the table. Move your uninjured leg across your body. Do 3 sets of 10.

Hold onto a chair if you need help balancing. This exercise can be made even more challenging by standing on a pillow while you move your uninjured leg.

• Resisted knee extension: Make a loop from a piece of elastic tubing by tying it around the leg of a table or other fixed object. Step into the loop so the tubing is around the back of your injured leg. Lift your uninjured foot off the ground. Hold onto a chair for balance, if needed.

I.        Bend your knee about 45 degrees.

II.       Slowly straighten your leg, keeping your thigh muscle tight as you do this.

Do this 10 times. Do 3 sets. An easier way to do this is to perform this exercise while standing on both legs.