Flexion of the Forearm at the Elbow Involves the Use

Question

Flexion of the forearm at the elbow involves the use of the principle of (a)________ lever(s).
A) first- and second-class
B) third-class
C) first-class
D) first- and third-class
E) second-class

Accepted Answer

Flexion of the forearm at the elbow involves the biceps brachii muscle, which is attached to the radius bone via a tendon. The effort (muscle force) is applied near the elbow joint, the fulcrum (joint), and the resistance (weight of the forearm) is at the hand. This arrangement forms a third-class lever, where the effort is in between the fulcrum and the resistance.