How many pounds of pressure does an M4 Carbine kick with?

I am currently in the Air Force and I just had shoulder surgery. My Dr. is trying to decide if he is going to discharge me, cross train me, or clear me. I need to know the approximate pounds of pressure of the recoil on a M4, M249, 240B, and M203 grenade launcher. Also an approximate weight of our hand grenade. I need answers quickly and there is no literature out there that can give me these answers. Thanks in advance.