What can you do about a pain in leg after injury?

R.I.C.E.: Rest, ice, compression and elevation. If the injury is mild and you are able to bear weight on the extremity without difficulty the standard conservative measures are ice, elevation, and tylenol (acetaminophen) or ibuprofen. If you have any doubts about your injury have it examined by a professional.

Depends: For general musculoskeletal pain, Ibuprofen (motrin/advil) is the standard and sometimes ice to the area may help (within the first 48 hours) but depending on your injury type might require evaluation by your physician. If you believe the injury is more than a simple muscle strain, see you doc.