While sitting last night, I was struck by a sudden burst of pain from my left instep, followed by swelling and eventually bruising. This morning I woke up with my leg asleep and a bruise the size of a silver dollar on my arch . I am able to walk normally, but there is now minor pain radiating from that spot on my foot up through my achilles tendon and into my lower calve. What is going on? I looked it up and have not found any kind of similar situation.