We can build a working model of an arm with a few materials.
Explanation:
Building the arm model
Cut two 8”*11” sections from a posterboard. roll it and secure it with a tape. These two pieces are the radius and ulna.
Cut a 12”*11” section from the posterboard and roll it like earlier to make the humerus.
Connect radius, ulna and humerus by piercing holes on ends of the bones and passing metal strip through the holes. Tie humerus on the left end and radius and ulna on towards the right. Place radius above ulna and humerus.
Use inflated balloons as biceps and triceps muscles. Tie one balloon connecting the right end of radius and ulna and top of the humerus. This is the biceps balloon. Tie the triceps balloon connecting the top of the humerus and the knee joint. Now a working model of arm is made.
