Question

multiple choice question
the joint at the base of the thumb is a ______ joint.
o hinge
o condylar
o saddle
o ball - and - socket

Explanation:

The base - of - thumb joint allows for a wide range of motion including opposition. Saddle joints have a unique shape that enables this type of movement. Hinge joints allow only flexion and extension, condylar joints allow some rotation and flexion/extension, and ball - and - socket joints allow multi - directional movement but have a different structure than the thumb base joint.

Answer:

C. saddle