AQA GCSE · Question 16.3 · The Human Body and Movement in Physical Activity and Sport
Describe two components of the second-class lever system identified in Question 16.2, using the ankle as the example.
How to approach this question
Based on your knowledge that the ankle during plantar flexion is a second-class lever, identify and describe two of the three components: Fulcrum, Load, or Effort, relating them specifically to the anatomy of the ankle and foot.
Full Answer
1. Fulcrum: The fulcrum is the pivot point, which is the ball of the foot.
2. Load: The load (or resistance) is the body weight acting down through the ankle.
In the second-class lever at the ankle during plantar flexion (pushing off):
- **Fulcrum:** This is the pivot point of the lever. In this case, it is the ball of the foot, where the foot pivots on the ground.
- **Load:** This is the weight or resistance that the lever is working against. Here, it is the entire body weight of the swimmer, acting downwards through the ankle bones (tibia).
- **Effort:** This is the force applied to move the load. The effort comes from the contraction of the gastrocnemius (calf) muscle, which pulls up on the heel bone via the Achilles tendon.
Common mistakes
Correctly identifying a component (e.g., 'fulcrum') but failing to relate it to the correct anatomical part (e.g., saying the fulcrum is the ankle joint itself).
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