I came across a particular result which bothered me, it stated that: Result: A person bending to 90 degrees at the waist with their back to a cliff will fall because their center of mass is past their feet. This statement perturbed me, because, when I applied it myself, I found that, while I did fall, my muscles were tensing before I fell. Thus, if my muscles were strong enough would I have been able to prevent myself from falling? One of my friends tried to apply the laws of levers and fulcrums to this problem, claiming that gravity acted as a torque around the fulcrum of your feet, and that there was no way to stop yourself from falling without applying some external force, like throwing a rock. However, this may be true but it doesn't seem to explain the case where a greater mass is off the cliff, being held up by sufficient muscular strength by a lighter mass on the cliff. That is to say, if I were holding 300 pounds of weight in my sufficiently strong arms straight out from my body, I would fall forward, regardless of the upward force I exert on the weight with my arms. This seems incorrect, because I believe that the upward force exerted by the arms, generates a reciprocal force that pushes your feet down onto the ground, thus this force allows you to stay on the ground rather then fall, regardless of the fact that a greater amount of mass is off the cliff (the heavy rock) then on the cliff (the man holding the rock). If something came across as unclear, feel free to ask for a further explanation of the problem. If anyone can shed any light on this matter I’d be most appreciative. Thanks.