“Sloths have such a STRONG GRIP that they’ve been known to continue hanging UPSIDE DOWN from a tree even after they die.”

National Geographic Kids, 5,000 Awesome Facts, #24 sloths

Sloth’s grip is twice as strong as a human and other primates. Most other primates are stronger in their back legs, which is the opposite of the sloth. Sloth’s back legs are very weak and don’t contribute much to their ability to hang from a tree. 

However sloths can only pull with their “hands”, and not push. 

Sloths can suspend its entire body weight from a single limb, holding it at a 90 degree for over 10 minutes. They can also suspend themselves between 2 tree branches in a crucifix position for an undetermined amount of time.

Their grip, being twice that of humans, can actually withstand the force of a harpy eagle trying to pry it from the branches, which is one of the sloth’s predators. 

They sleep gripped to a tree, they mate gripped to a tree, and even give birth while gripping onto a tree. 

And, they can die clutching onto the branches of its favorite tree. 

For some reason, sloths are stronger on their left side. They are also capable of holding 100% of their body weight with one hand.

The reason for such a strong grip is they have specialized tendons in their hands and feet that lock into place, allowing them to hang down for long periods of time, hence in slumber and in death.

Sources:

https://studyfinds.org>sloths-grip-strength

slothconservation.org