How to treat torn ligament in foot?

First, be sure it is a torn ligament. A doctor will need to examine it to be sure it is not a cracked or broken bone, or a bad sprain - all three of these things feel equally painful (actually I had a bad sprain once that hurt worse than the time I broke a bone in my ankle).

If it is torn, you will probably have a strap-on cast to wear that will hold the ligament in place while it heals - this will take anywhere from six weeks to six months. Ligaments are hard to heal because there is not a good blood supply to a ligament.

You should prepare to have some arthritis in the area after middle age if it is torn, because it will always be weak and the scar tissue never gets quite as flexible as the area once was, so it gets damaged more easily. You should stay off that foot as much as possible while it is healing, and do whatever physical therapy exercises the doctor gives you (usually stretching exercises). Ice packs (hold them on the area for 15 minutes, then remove to prevent frostbite and leave off for 15 minutes) and elevation (put the foot on a pillow or footstool) are also good. Ibuprofen (2-3 over-the-counter tablets every eight hours with food) will help with pain and swelling.

A ligament injury is never going to heal 100% back to normal. You're going to have to do a tremendous amount of PT once the healing process begins.

Ice, elevation and stabilization are the only things that are going to help you during the first week or so. Start PT as you feel your comfort level rising.

First exercise. Range of motion: Remove your stabilizing boot. Sit on a tall stool, a bed or something that will allow your ankle to hang. Slowly trace the letters of the alphabet with your foot.

See an orthopedic doctor (specialist) for the rest of the exercises.