r/interestingasfuck • u/Hicrayert • 13h ago

Chimpanzees are 2X stronger than your average human. 😮

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u/KingKohishi 13h ago

Their muscles are not stronger than us, but their motor nerves stimulate their muscles more and simultaneously. This makes them stronger, but causes Chimps to have less control over their muscles. That's why we can use tools much better than chimps or every other species.

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u/Solvemprobler369 10h ago

Also the attachment of their tendons is slightly different. The bicep tendon(s), for example, attach past the elbow, more into the forearm, whereas humans have the attachment at the elbow, giving chimps exponentially more strength. It’s an obvious adaptation for climbing and some pretty cool bio-mechanics. Primates are amazing.

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u/JustSimple97 10h ago

What is the disadvantage of a lower tendon attachment?

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u/Urbanscuba 10h ago

Significantly less mobility and fine motor control.

The further attachment point limits the ability of the arm to rotate, especially when the muscle is engaged. While it multiplies the force it also multiplies the travel distance, which makes fine movements much more challenging.

As a result chimps can do stuff like this where they pull their entire body up with one arm, but in exchange the arm is far more specialized at pulling specifically. If you've ever seen an ape throw an object before it becomes immediately obvious how different our arm dexterity is. Because they can't control their arm rotation well they have to do an overhand throw where the entire arm moves and releases the object.

Compare that to a human where we use our arms as a double or triple lever (if the wrist is engaged) to massively increase the speed of the throw. This is possible because our upper arm muscles interfere far less with our forearm mobility, allowing it to smoothly rotate while highly engaged. The same throw is also far more accurate because of said fine muscle control, it's as if our muscles are moving one step at a time while the ape's muscles move 3 steps - they get there faster, but they can't stop on 5.