That means if we have more of these motor units that are involved in creating that motion, we're going to produce a greater force. Likewise, if we have less of these motor units involved we're going to produce a smaller force. Now to see what we mean, let's take a look at the following diagram once more. So let's suppose I take the following marker and I try to curl my hand. So I tried to basically raise the marker. I tried to exert a force that basically does work against the force of gravity which is pulling down on this marker.