The Most Powerful Muscle

The gluteus maximus is the largest muscle in the human body. But is it the most powerful?

The only website I found that used those exact words was LiveScience, which says that the myometrium, or uterine muscle, may be "the most powerful" because its ability to contract and relax makes human birth possible.

LiveScience was actually asking what was the strongest muscle. It starts with the soleus, or lower calf muscle, citing Gray's Anatomy (note: not Grey's Anatomy) – because it can exert the most force. But the masseter (or jaw muscle) exerts the most pressure, the tongue may be the most versatile, and "if slow and steady wins the race, the heart is certainly a contender for the title."

Lots of websites ask the same question – what's the strongest muscle – but (as you may have already gathered), this is not an easy question to answer. MedicineNet.com explains that "The strongest muscle in the body is debatable. Some physiologists believe it's the masseter (used for chewing), while others claim it's the gluteus maximus (buttocks), or the rectus femoris (part of the quadriceps in the thigh). It's not easy to determine partly because muscles don't work alone. For example, you wouldn't be able to isolate the rectus femoris muscle and compare it directly to others because other quadriceps muscles contract along with it."

The Library of Congress is similarly unable to give a definitive answer. It nominates the eye muscles for their frequency and rapidity of movement, the heart for being the hardest working, the masseter for its strength to weight ratio, the muscles of the uterus for their ability to push a baby through the birth canal, the soleus (see above) because like the gluteus maximus, it enables us to stand upright, and the tongue because like the heart, it's always working.

In conclusion: for quiz purposes, you can ask what's the largest muscle in the human body, but I would suggest that you can't ask what's the strongest (or the most powerful) because there's no definitive answer.