when you are NOT running???
I have been reading in other threads about people with "pains" in their calf muscles. Firstly, running uses muscles that we don't normally use when walking - and also uses muscles repetitively. This latter situation causes a form of mild RSI ( repetitive strain injury). Many peoples calf ( and other) muscles are very weak and underdeveloped due to their previous sedentary lifestyle.
BUT - calf muscles in particular are affected by the conditioning they have been receiving from the style of shoes (especially heel height for women) that they have been wearing for many years of your "non"-running life .