Ape Index

Ape index, or ape factor, or gorilla index is a measure of the ratio of an individual's arm span relative to their height. A typical ratio is 1, as identified by the Roman writer, architect and engineer Vitruvius prior to 15 BC. Vitruvius noted that a "well made man" has an arm span equal to his or her height, as exemplified in Leonardo da Vinci's drawing, the "Vitruvian Man". In rock climbing it is believed that a positive Ape Index, (a value greater than 1), where the arm span is greater than the height, provides for a competitive advantage, and some climbers have expressed the belief that exercise can result in an improved ratio.