Ape index

Vitruvian Man c. 1492 by Leonardo da Vinci. Based on proportions identified by Vitruvius, the drawing shows a man where the arm span is equal to the height, giving an ape index of 1.

Ape index, ape factor,[1] or gorilla index is slang or jargon used to describe 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 height, as exemplified in Leonardo da Vinci's c. 1492 drawing, the Vitruvian Man.[2] In rock climbing it is believed that an ape index greater than one, 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, although this view is somewhat controversial.[3]

  1. ^ McIver, Kelly (September 8, 1992). "Rock climb jargon often tough to scale". Eugene Register-Guard. p. 5D. Archived from the original on February 27, 2022. Retrieved September 2, 2009.
  2. ^ Pheasant 1996, p. 7.
  3. ^ Sagar 2001, p. 144.