And so now let's suppose I'm using all three of these motor neurons and that means I'm using all three of these motor units. And this as a result of me using more of these motor units I will produce a greater force because more of these motor units contain more of these muscle cells and so I will exert a greater force. So if we stimulate many motor units to carry out a certain activity this will produce a greater force than if we use a smaller number of motor units. And this is simply because more motor units means we're using many more muscle fibers, many more muscle cells. And finally, let's move on to number three. So the thickness of the muscle cells also influences the force, the magnitude of the force that we're creating.