Good point. The old Marvel handbooks said that Quicksilver had superhuman strength in his legs, which makes sense considering that he doesn't have the Speed Force or anything like it granting him speed. So he is literally just running really fast. But Quicksilver doesn't have any strength feats beyond anything we have seen for CBPH characters. Quicksilver can blitz mooks and CBPH characters, but wasn't able to put Spider-man down when they fought. Here is Quicksilver admitting that his punches aren't stopping Spider-man: