What kind of motion is possible with a hinge joint?

backward or forward

sliding

rotating

side to side

I believe that the answer is backward or forward.

Reason:

"A hinge joint is a common class of synovial joint that includes the ankle, elbow, and knee joints. Hinge joints are formed between two or more bones where the bones can only move along one axis to flex or extend" (aka backward or forward)

flexion and extension

Explanation:

Flexion is the bending and extension