Hinge

your knee is a door. your hip is a joystick.

pose a wooden mannequin until each joint refuses what it cannot do

An artist’s mannequin is not a bendy wire. It is a stack of joints, and each kind permits exactly its own motions and refuses the rest. The elbow and the knee are the same hinge pointed opposite ways — one folds toward you, one folds away, and neither will go backward. Anatomy counts six kinds of synovial joint; this lets your hand find three of them, hinge, ball and pivot, by pushing each one until it stops. Pose it and it draws itself, which is what the object is for.

Concepts: anatomy, rotation.

An interactive you play with one thumb, on Wundr.