Suzy, is it a recent injury or an older injury?
If it is recent, and there is swelling, you might try ice.
If it is older try ice then heat.
Only keep the ice or the heat on for 1/2 hour. 20 minutes on, 20 minutes off. You can alternate.
You should contact your doctor for a referral to a physical therapist.
Please refer to my answer to your first question
here.