The lever is a simple machine. It makes it possible to transfer work done in one place, to another place.
The human arm is a lever.
The muscle is attached by a
tendon at each end, to the bone.
An
average tendon can carry up to 100 lbs or 45 kg. The place of the
attachment is important. If the muscle went from A to B the effort
would be enormous, but it has been designed to go from A to C.
This
means the hand moves seven times further that the forearm.
It also
means the hand can move seven times faster. This
enables humans to play
fast sports, and to play the piano
and other instruments at great speed.
The human arm lever also enables us to do very delicate movements - such as painting, or surgery.
The lever system is our legs gives us the ability to run,
jump, hop, and kick a ball.
lever system in our mouth enables us to bite and chew
food. The mechanical ratio is such that the back
teeth can close with TWICE the pressure as the
front teeth.
Muscles tend to work in
pairs. As the arm moves, the muscles on the underside contract. To
raise the arm the muscles on the upper side contract. The harmony is so
complete we hardly ever notice this.
