Hey guys, so today we are going to go over
a simple, effective way to understand the convex concave rule... especially for all
you visual learners out there! Purpose of this rule is to understand the
arthrokinematics. So basically, the way different joints, such
as the shoulder and elbow move. So lets define what each surface looks like! Here is the concave surface and this is the
convex surface. I find it easier to differentiate by thinking
of the concave surface as the surface CAVED in. Now, lets get into the rule itself. The convex concave rule depends on which surface
is moving. So lets get into an example of the concave
surface moving. In the elbow, the ulna is concave and the
humerus is the convex surface. As you can see, when the concave surface moves,
the surface and the bone slide in the same direction. Now, lets look at the convex surface moving
instead. In the shoulder, the humerus, which is the
convex surface, is moving on the scapula, which is the concave surface. As the convex surface moves down, the bone
moves in the opposite direction. So basically... thats it for the convex concave rule! If you have any questions related to physical
therapy or the video, please leave a comment below. And THANK YOU FOR WATCHING!!