Concave and convex rule !

Concave and convex rule !

  All of the gliding we show you are based on the concave and convex rule.

So, here we put us a little revision of the rule to understand better.

The gliding's direction depends of the bone we move, why?

• If we move the bone with the concave surface, the gliding and the bone go in the same direction. It's the concave rule

the red arrow : gliding, the green arrow: movement's direction.

• If we move the bone with the convex surface, the gliding and the bone don't go in the same direction. It's the convex rule

the red arrow : gliding, the green arrow: movement's direction.