Realising that the character will need to be able to pick up a weapon and fire, I created a new pose where the character can hold a weapin- in this case a gun, and also run. There is a little movement in the shoulder and torso, but not greatly as it needs to give the appearance of fireing in a straight line rather than waving it about wildly.
I will not be adding any sort of fancy pick up motion, the change in position will be automatic.
The gun (mock-up):
Character running and holding the gun: