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Now that you understand the three classes of lever, you need to be able to apply this knowledge to real sporting actions. AQA GCSE PE (spec 3.1.2) requires you to identify the lever class, fulcrum, load and effort for movements at the elbow, knee and ankle. This lesson works through the key sporting examples you need to know and provides a structured approach to analysing any lever system in sport.
For AQA GCSE PE, you need to focus on lever systems at three joints:
| Joint | Lever Class (main action) | Key Sporting Actions |
|---|---|---|
| Elbow | Third class (flexion and extension) | Bicep curl, push-up, throw-in, shot in basketball |
| Knee | Third class (extension) | Kicking a ball, squats, jumping |
| Ankle | Second class (plantarflexion) | Running (push-off), jumping (take-off), calf raise |
When you flex (bend) your elbow — for example, during a bicep curl or a football throw-in — you are using a third class lever.
| Component | What It Is |
|---|---|
| Fulcrum (F) | Elbow joint |
| Effort (E) | Biceps brachii muscle (inserts on the radius, close to the elbow joint) |
| Load (L) | Weight of the forearm + whatever is being held (ball, dumbbell, etc.) |
Order: F — E — L (Third class)
graph LR
F["F<br>Elbow joint"] --- E["E<br>Biceps"] --- L["L<br>Weight in hand"]
style F fill:#e74c3c,color:#fff
style E fill:#27ae60,color:#fff
style L fill:#4a90d9,color:#fff
Sporting examples of elbow flexion:
| Sport | Action | Description |
|---|---|---|
| Football | Throw-in | The player flexes at the elbow to bring the ball behind the head, then extends to release |
| Basketball | Shooting / passing | Elbow flexion and extension control the ball release |
| Weightlifting | Bicep curl | The classic example of elbow flexion against resistance |
| Cricket | Catching | The hands move towards the body as the elbow flexes to absorb the ball |
| Boxing | Uppercut | Rapid elbow flexion drives the fist upward |
When you extend (straighten) your elbow — for example, during a push-up or a netball chest pass — you are still using a third class lever, but now the triceps provides the effort.
| Component | What It Is |
|---|---|
| Fulcrum (F) | Elbow joint |
| Effort (E) | Triceps brachii muscle (inserts on the olecranon process of the ulna, close to the elbow joint) |
| Load (L) | Weight of the forearm + whatever is being pushed (body weight in a push-up, ball in a chest pass) |
Order: F — E — L (Third class)
Sporting examples of elbow extension:
| Sport | Action | Description |
|---|---|---|
| Gymnastics | Push-up / handstand | Triceps extend the elbow to push the body up |
| Netball | Chest pass | Arms extend to push the ball forward |
| Basketball | Chest pass | Same as netball — elbow extension propels the ball |
| Shot put | Release | Extension at the elbow pushes the shot forward |
| Rugby | Push in a scrum | Arms extend against the opposing pack |
Exam Tip: Both flexion and extension at the elbow use third class levers. The only difference is which muscle provides the effort: biceps for flexion, triceps for extension.
When you extend (straighten) your knee — for example, when kicking a football or standing up from a squat — you are using a third class lever.
| Component | What It Is |
|---|---|
| Fulcrum (F) | Knee joint |
| Effort (E) | Quadriceps muscle group (inserts via the patellar tendon on the tibial tuberosity, close to the knee joint) |
| Load (L) | Weight of the lower leg (shin + foot) + any external load (ball, weight) |
Order: F — E — L (Third class)
graph LR
F["F<br>Knee joint"] --- E["E<br>Quadriceps"] --- L["L<br>Lower leg + ball"]
style F fill:#e74c3c,color:#fff
style E fill:#27ae60,color:#fff
style L fill:#4a90d9,color:#fff
Sporting examples of knee extension:
| Sport | Action | Description |
|---|---|---|
| Football | Kicking the ball | Powerful knee extension drives the foot into the ball |
| Rugby | Kicking (penalty, drop goal) | Same principle as football kicking |
| Gym / Fitness | Squats | Knee extension against body weight or barbell |
| Athletics | Take-off in long jump | Knee extends powerfully to propel the body upward and forward |
| Volleyball | Jumping (spike / block) | Knee extension provides the force for the jump |
| Cycling | Pedal push | Quadriceps extend the knee to push the pedal down |
The quadriceps insert close to the knee joint (via the patellar tendon just below the kneecap). This means the effort is applied close to the fulcrum — placing it between the fulcrum (knee) and the load (lower leg + foot). This arrangement sacrifices power but gives the lower leg a large range of movement and high speed — essential for kicking and running.
When you rise onto your tiptoes or push off during running and jumping, you are performing plantarflexion at the ankle. This is the most important example of a second class lever in the body.
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