How Can Foot Injury Causing Calf Muscle Pain Be Treated?

Hi Doctor, I got a foot injury 20 days back. Although the pain in foot is now not severe but i developed muscle pain around the calf which is unbearable many a times. If I dont walk then there is no pain, but as soon as I start walking the pain starts. Doctors medicine are only reducing the pain when I take but the problem is not getting cure. I went through scans and xrays and the reports are fine. But why still the pain is continuing, no idea??
any help???