Question

why is it that we can move our elbow and knee only in one direction​

Answer 1

$\huge \underline \mathbb \blue {Answer :-}$

Hinge joints are found at the elbow and knee and they only allow movement in one direction or in only one plane. Hinge joints are formed between two or more bones where the bones can only move along one axis to flex or extend.

Answer 2

Answer:

Due to Hinge Joint

Explanation:

In hinge joints, the articulating ends of the bones fit together like a hinge on a door, and movement is therefore restricted to flexion and extension, i.e. movement is only in one direction. The elbow joint is an example, which permits movement only in one direction, i.e only in the forward direction.