Climbing requires the use of toes. Having the right foot shape allows climbers to stabilize their bodies on the wall.
The result of my testing reveals that it is ideal to climb with a foot that is about half the size of an average human foot.
Elastic ankle joint with limited range of motion can potentially provide shock absorption and comfort for climbers.
This unique feature is one of the reasons why mountain goats are such good climbers. I would like use this feature in my final design.