When in need of a defense mechanism, gorillas generally rely on their powerful arms, which are fully developed with strong muscles. Gorillas have strong and muscular arms, which allow them to fight off predators, grasp and break twigs and branches and move through trees. A strong upper torso distinguishes gorillas from many other animals, including humans.
While gorillas use their arms for support and defense, the opposite is true for humans. Humans have long and powerful legs, which have evolved to be the most powerful parts of the human skeleton after humans transitioned to living exclusively on the ground instead of trees. While the longest muscles and bones of humans are found in the legs, the arms of gorillas contain the longest muscles and strongest bones. The sturdy build of their upper torsos provide gorillas with tremendous amounts of strength. Their upper body strength, on average, is six times more than the upper body strength of humans, which allows them to easily lift and crush heavy objects. Despite their large size and muscular build, gorillas are generally docile and shy animals, and attack only when threatened or provoked. In addition to long arms, gorillas have sharp and powerful teeth, which are used for biting through tough vegetation rather than for defense.