Assertion: elbow's joint | /r/CapableOf | allow extension
Facets:
Source sentences:
text: Hinge joints allow flexion and extension only.
text: Ellipsoidal joints, such as the joint at the base of your index finger, allow bending and extending, rocking from side to side, but rotation is limited.
text: Going back to the terminology from last week, the hinge joint allows flexion and extension.