1 Foot MB Pass
Performing any upper body pass with a medicine ball will work the upper body, however having one leg off the floor, will reduce your throwing ability, as you are removing the power from your lower body.
Aim to work each leg off the floor, measuring your maximum distance of each style of throw, with both one foot and both feet on the floor, so you can see the difference in power.
Focusing on maximum explosive power with each throw, aiming to use your core stability muscles to control your posture so that your foot stays off the floor.