Question

Give an example of each class of lever in a human body.

Answer 1

1. Class I lever in the action of nodding of the head: In this action, the spine acts as the fulcrum, load is at its front part, while effort is at its rear part.
   
2. Class II lever in raising the weight of the body on toes: The fulcrum is at the toes at one end, the load is in the middle and effort by muscles is at the other end.
   
3. Class III lever in raising a load by forearm: the elbow joint acts as a fulcrum at one end, the biceps exert the effort in the middle and a load on the palm is at the other end.