Brachiate

Some traits that allow primates to brachiate include a short spine (particularly the lumbar spine), short fingernails (instead of claws), long curved fingers, reduced thumbs, long forelimbs and freely rotating wrists. Modern humans retain many physical characteristics that suggest a brachiator ancestor, including flexible shoulder joints and fingers well-suited for grasping. In lesser apes, these characteristics were adaptations for brachiation. Although great apes do not normally brachiate (with the exception of orangutans), human anatomy suggests that brachiation may be an exaptation to bipedalism, and healthy modern humans are still capable of brachiating. Some children's parks include monkey bars which children play on by brachiating.