Contracting the Gastrocnemius Muscles to Elevate the Body on the Toes

Question

Contracting the gastrocnemius muscles to elevate the body on the toes involves a ________ lever.
A) first-class
B) second-class
C) third-class
D) fourth-class
E) fifth-class

Accepted Answer

In a second-class lever, the load (body's weight) is between the effort (contraction of the muscle) and the fulcrum (ball of the foot pushing off the ground). This type of lever allows for a greater force to be generated by the muscle (effort) to lift the load (body) with less effort required. The gastrocnemius muscle acts as the effort, the ball of the foot acts as the fulcrum, and the body's weight is the load in this movement.