Human (Homo sapiens sapiens)

The ankle joint of a plantigrade foot is an example of a 1st Order lever; the tibia, fibula, and tarsals form the fulcrum; the gastrocnemus muscle is contracting to raise the calcaneus bone; the foot is pushing off the ground and raising.

The ball of the foot joint shows a 2nd Order lever; the metatarsals and phalanges form the fulcrum; the tendons in the foot are attached to the gastrocnemus and pull the foot back; the toes are pushing off of the ground and lifting the foot.


This shows the levers of the ankle joint after the gastrocnemus in-force has acted to pull the heel anteriorly. The ball of the foot lever has not yet completed its action.

The ankle joint has a VR close to 4/1, and the ball of the foot lever's VR is around 1/4.