First, Second and Third Class Levers

Levers are one of the most important mechanical concepts in OCR GCSE PE (J587 — Physical Factors Affecting Performance). The human body is full of lever systems — every time you move a limb, you are using a lever. Understanding how levers work helps you analyse sporting movements and explain why certain body parts are better suited to certain actions. This lesson covers the three classes of lever, how to identify them, and how to draw and label lever diagrams.

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What Is a Lever?

A lever is a rigid bar (bone) that turns around a fixed point (joint) when a force is applied. In the human body, the skeletal and muscular systems work together to create lever systems that produce movement.

Every lever system has three components:

Component	What It Is in the Body	Symbol
Fulcrum (F)	The joint (pivot point) around which the lever rotates	F
Load (L)	The resistance or weight being moved (body part, object, opponent)	L
Effort (E)	The force applied by the muscle to move the load	E

Exam Tip: You must be able to identify the fulcrum, load and effort in any lever system. Always think: F = joint, L = weight/resistance, E = muscle force.

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The Three Classes of Lever

The class of a lever is determined by the arrangement of the fulcrum, load and effort. There are three possible arrangements, giving three classes of lever.

First Class Lever (Fulcrum in the Middle)

In a first class lever, the fulcrum is between the effort and the load.

Arrangement: Effort — Fulcrum — Load (or Load — Fulcrum — Effort)

graph LR
    E[Effort<br>E] --- F[Fulcrum<br>F] --- L[Load<br>L]
    style E fill:#27ae60,color:#fff
    style F fill:#e74c3c,color:#fff
    style L fill:#4a90d9,color:#fff

Everyday example: A seesaw. The pivot (fulcrum) is in the middle, with the effort (person pushing down) on one side and the load (person being lifted) on the other.

Body example: Nodding the head (extension at the neck).

• Fulcrum: The atlanto-occipital joint (the joint between the skull and the top of the spine, at the base of the skull).
• Effort: The muscles at the back of the neck pulling down on the back of the skull.
• Load: The weight of the face and front of the skull (gravity pulling the head forward).

Component	In the Body
Fulcrum (F)	Atlanto-occipital joint (top of spine)
Effort (E)	Neck muscles (pulling down at the back)
Load (L)	Weight of the face/front of skull

Key feature of first class levers: They can be used for balance or to change the direction of the force. First class levers in the body are relatively rare.

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Second Class Lever (Load in the Middle)

In a second class lever, the load is between the fulcrum and the effort.

Arrangement: Fulcrum — Load — Effort

graph LR
    F[Fulcrum<br>F] --- L[Load<br>L] --- E[Effort<br>E]
    style F fill:#e74c3c,color:#fff
    style L fill:#4a90d9,color:#fff
    style E fill:#27ae60,color:#fff

Everyday example: A wheelbarrow. The wheel (fulcrum) is at one end, the heavy load is in the middle, and you lift (effort) at the handles.

Body example: Rising on tiptoes (at the ankle).

• Fulcrum: The ball of the foot (metatarsophalangeal joint area / the point where the foot contacts the ground).
• Load: Body weight acting through the ankle joint (the tibia pushing down).
• Effort: The calf muscles (gastrocnemius) pulling up on the heel via the Achilles tendon.

Component	In the Body
Fulcrum (F)	Ball of the foot (where the foot contacts the ground)
Load (L)	Body weight (acting downward through the tibia/ankle)
Effort (E)	Calf muscles pulling up on the heel (Achilles tendon)

Key feature of second class levers: They are power levers. The effort arm is always longer than the resistance arm, which means a large load can be moved with relatively less effort. This is why the calf muscles can support and lift the entire body weight.

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Third Class Lever (Effort in the Middle)

In a third class lever, the effort is between the fulcrum and the load.

Arrangement: Fulcrum — Effort — Load

graph LR
    F[Fulcrum<br>F] --- E[Effort<br>E] --- L[Load<br>L]
    style F fill:#e74c3c,color:#fff
    style E fill:#27ae60,color:#fff
    style L fill:#4a90d9,color:#fff

Everyday example: A pair of tweezers or a fishing rod. The pivot is at one end, the force (effort) is applied in the middle, and the object (load) is at the far end.

Body example: Flexion at the elbow (e.g. a bicep curl).

• Fulcrum: The elbow joint.
• Effort: The biceps muscle, which inserts on the radius just below the elbow.
• Load: The weight held in the hand (or the weight of the forearm and hand themselves).

Component	In the Body
Fulcrum (F)	Elbow joint
Effort (E)	Biceps muscle (inserts on radius, close to the elbow)
Load (L)	Weight in the hand / weight of the forearm

Key feature of third class levers: They are speed and range of movement levers. Because the effort is applied close to the fulcrum, a small contraction of the muscle produces a large range of movement at the load end. However, the trade-off is that more effort is needed to move the load — third class levers sacrifice power for speed and range.

Exam Tip: Third class levers are the most common type in the human body. Most limb movements (bicep curl, kicking, throwing) use third class levers because the human body is designed to prioritise speed and range of movement over brute force.

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Summary Comparison of All Three Classes

Feature	First Class	Second Class	Third Class
Arrangement	E — F — L	F — L — E	F — E — L
Fulcrum position	Middle	One end	One end
Body example	Nodding the head	Rising on tiptoes	Bicep curl
Everyday example	Seesaw	Wheelbarrow	Tweezers / fishing rod
Main advantage	Balance, direction change	Power (large load, less effort)	Speed and range of movement
Common in body?	Rare	Uncommon	Very common

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Mnemonic Aids for Remembering Lever Classes

Mnemonic 1: "1-2-3, F-L-E"

Think of the word FLE (Fulcrum, Load, Effort). For each class, the component in the middle shifts:

• 1st class: Fulcrum in the middle — FLE
• 2nd class: Load in the middle — FLE
• 3rd class: Effort in the middle — FLE

Mnemonic 2: "1-2-3"

• 1 = fulcrum in the middle (like a seesaw — balanced on 1 pivot point)
• 2 = load in the middle (a wheelbarrow carries the load — 2 handles)
• 3 = effort in the middle (tweezers — 3 fingers used to squeeze)

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Common Exam Mistakes

• Mixing up the three classes — use the FLE mnemonic to remember which component is in the middle for each class.
• Confusing effort and load — the effort is ALWAYS the muscle force; the load is ALWAYS the resistance/weight.
• Forgetting to identify the fulcrum as a joint — in the body, the fulcrum is always a joint, not a bone or muscle.
• Not knowing the body example for each class — first class = neck (nodding), second class = ankle (rising on tiptoes), third class = elbow (bicep curl). Learn these three core examples.
• Saying second class levers are the most common — third class levers are the most common in the human body.

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Summary

• Every lever system has three components: fulcrum (joint), load (resistance/weight), and effort (muscle force).
• First class lever: fulcrum in the middle (E-F-L). Body example: nodding the head. Advantage: balance.
• Second class lever: load in the middle (F-L-E). Body example: rising on tiptoes at the ankle. Advantage: power.
• Third class lever: effort in the middle (F-E-L). Body example: bicep curl at the elbow. Advantage: speed and range of movement.
• Third class levers are the most common in the human body.
• Use the FLE mnemonic to remember the arrangement for each class.