Fig. 1 shows a performer standing on tiptoe. The foot acts as a lever system during this movement. (a) Name the class of lever that the foot represents in t...

(a) The foot represents a second class lever. [1]

In a second class lever, the load is positioned between the fulcrum and the effort. This arrangement provides a strong mechanical advantage, meaning a relatively small effort can move a large load.

(b) The fulcrum is located at the toes (the ball of the foot), specifically the metatarsophalangeal joint. [1] This is the point around which the foot pivots when rising onto tiptoe.

(c) This type of lever is advantageous for a sprinter leaving the starting blocks because:

• It produces a large force output relative to the effort applied, giving a powerful push-off against the blocks. [1]
• This helps the sprinter accelerate quickly from a stationary position by generating maximum force against the ground in the drive phase. [1]

The gastrocnemius (calf muscle) provides the effort by pulling upward on the heel (calcaneus), the body weight acts as the load through the ankle, and the toes act as the fulcrum on the ground.

(d) Another sporting example of a second class lever in the body:

• Example: A header in football, where the performer pushes up onto their toes to gain height, or a basketball player jumping for a rebound. [1]
• Fulcrum: The toes / ball of the foot (the same pivot point applies whenever the body rises onto tiptoe). [1]