The question of the most powerful muscle in the body has several different
answers depending on what you mean.
If you want to know the muscle that can pull with the greatest force, that
would go to the soleus in the back of the lower leg. That muscle is
connected to the achilles tendon that attaches to the heel bone of the
foot. A 300 pound man can raise himself up on the ball of one foot
primarily using the soleus with some help from the gastrocnemius. The
mechanical leverage gives the foot a speed advantage of about 2:1 so the
soleus muscle would have to pull with 600 pounds to accomplsh this feat.
If you want to know the muscle that is strongest for its weight, that
distinction would go to the 1 ounce maseeter muscle in the cheek. This
little muscle helps you close your jaw in chewing and pulls with
approximately 200 pounds of force.
If you want to know the muscle that does the most work, that award goes to
the heart. It works continuously and only rests for a fraction of a
second between contractions. The heart weighs only about 1 pound but does
more work than all of the other muscles in the body put together.
All of these observations are for muscles working under normal
circumstances. If an outside electric charge is used to stimulate a
muslce, it can contract with all of its capacity. That can result in
breaking bones, pulling tendons from thier insertions, and tearing the
muscle itself. Stimulated by the hormone adrenaline (the fight or flight
hormone), people have been known to do some fantastic feats of strength.
One report tells of a mother who saw her young son run over by a car, lift
the car from her son so he could be removed. She could never have moved
that heavy weight without the help of the adrenaline.
Our muscles are much stronger than we realize. There are built in safety
mechanisms to keep us from hurting ourselves.
