A sprain happens when a ligament stretches or tears. Ligaments are stretchy bands that connect bones to each other. A knee sprain usually happens because the knee gets twisted, bent, or hit. 

A sprain can be mild or severe. It can take a few days, weeks, or longer to feel better. Follow these instructions to help your child as the sprain heals.

• For 2–3 days, to help with pain and swelling:
  • Have your child rest the knee and avoid any activities that cause pain.
  • Place ice wrapped in a towel on the sprain for about 20 minutes several times a day. Do not put ice directly on the skin.
  • Wrap the knee in an elastic bandage. The bandage should be tight enough to provide gentle support but loose enough that you can easily fit your finger under the edge.
  • Keep the knee above heart level by resting it on a pillow.
• Follow your health care provider's advice for:
  • Giving your child acetaminophen (Tylenol^® or a store brand) or ibuprofen (Advil^®, Motrin^®, or a store brand) as needed for pain. Follow the directions on the label for how much to give and how often.
  • Using a splint, brace, or crutches to protect the knee.
  • Any movement exercises or stretches your child should do and any activities to avoid.
  • When it's OK to try a heating pad and massage (usually after the swelling goes down).
  • Whether your child should go to a bone doctor (orthopedist), sports medicine doctor, or physical therapist to help them build strength and flexibility and create a plan for returning to full activities and sports.
  • When your child should follow up.
• Adding activities:
  • If your health care provider says it's OK, your child can gradually increase activities after about 2–3 days of rest. At first, they can try stretching and low-impact activities like swimming, walking or running in the water, or riding a stationary bike. If they have no pain, they can continue to add more activities and training.
  • If your child has increased pain or swelling, they have probably tried to do too much. They should stop the activity they're doing and take a rest or switch to a less intense activity.
  • Talk to your health care provider if you're not sure which activities your child should do.

• The pain or swelling gets worse.
• After a week of following your health care provider's instructions, your child:
  • has pain or swelling that isn't getting better
  • can't bend or fully straighten the knee
  • can't put weight on the knee
  • has times when the knee "gives way" (suddenly feels unstable, weak, or unable to bear weight)

How are knee sprains diagnosed? Health care providers ask questions and examine the injured area. A sprained knee might be swollen, painful, stiff, or sore. The skin around the knee might look red or bruised. It might be painful to stand or walk. Sometimes the health care provider orders X-rays to make sure there is no broken bone.

What can help prevent knee sprains? To prevent injuries to the knee, encourage your child to:

• Wear the right protective gear during practice and competition (such as shin guards or knee pads).
• Wear supportive athletic shoes that are in good condition.
• Warm up before sports activities.
• Bend the knees and hips when landing from a jump or making a quick turn.
• Do regular strengthening and flexibility exercises.
• Be active year-round, which will help their knees and the rest of their body stay in good shape.