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The numerous bones in the human wrist enables it to rotate along two axes, which differs from primates. The shape of the wrist bones in humans permits rotation along the plane of the radius and ulna, which is called a dart-thrower motion and enable the precision use of tools and implements.
However primates have a different configuration of wrist bones that is suited to swinging from tree branches, but are unable to execute the 'dart-throwing' motion. This might explain why primates use tool implements differently from humans.
Click on the image below to see an animation of the motion of Human Wrist Bones
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