Re: What is the most powerful muscle in your body?

Dear Sarah,

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.

I hope this helps.