Functions of the Skeleton

This lesson covers the six functions of the skeleton as required by the AQA GCSE PE specification (3.1.1.1). You need to know each function, be able to explain it clearly, and apply it to sporting examples. This is a topic that appears regularly on exam papers, often as a short-answer or extended-response question.

The six functions are: support, protection, movement, shape and muscle attachment, mineral storage, and blood cell production. Each one is essential for performance in physical activity.

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Overview of the Six Functions

graph TD
    A["Functions of the Skeleton"] --> B["Support"]
    A --> C["Protection"]
    A --> D["Movement"]
    A --> E["Shape & Muscle Attachment"]
    A --> F["Mineral Storage"]
    A --> G["Blood Cell Production"]

    style A fill:#4a90d9,color:#fff
    style B fill:#e67e22,color:#fff
    style C fill:#e67e22,color:#fff
    style D fill:#e67e22,color:#fff
    style E fill:#e67e22,color:#fff
    style F fill:#e67e22,color:#fff
    style G fill:#e67e22,color:#fff

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1. Support

The skeleton provides a rigid framework that supports the body and holds it upright against the force of gravity. Without the skeleton, the body would collapse into a shapeless mass on the ground.

How Support Works

• The vertebral column (spine) acts as the central pillar of support, holding the head, ribcage, and upper body upright.
• The pelvis supports the weight of the upper body and transfers it to the legs.
• The femur, tibia, and fibula support the body's weight when standing, walking, and running.
• The ribcage supports and holds the lungs and heart in place.

Sporting Examples

Sport / Activity	How Support is Demonstrated
Standing start in sprinting	The skeleton holds the athlete in an upright crouched position in the blocks
Gymnastics — holding a handstand	The arms and shoulder girdle support the entire body weight inverted
Weightlifting	The spine and legs support the body while additional weight is held overhead
Ballet — standing on pointe	The bones of the foot and lower leg support the dancer's body on the tips of the toes

Exam Tip: When explaining support, always refer to specific bones. Do not just say "the skeleton supports the body" — name the bones involved. For example: "The vertebral column supports the upper body and head during a standing position in football."

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2. Protection

The skeleton protects vital organs from damage. Bones are hard and rigid, forming a shield or cage around soft, delicate organs.

Key Examples of Protection

Bone(s)	Organ(s) Protected
Cranium	Brain
Vertebrae	Spinal cord
Ribs and sternum	Heart, lungs, and liver
Pelvis	Bladder, intestines, and reproductive organs

Sporting Examples

• Rugby — the cranium protects the brain during tackles and collisions. Despite this protection, concussions can still occur, which is why headguards and concussion protocols are used.
• Boxing — the ribs and sternum protect the heart and lungs from body blows.
• Football — a goalkeeper diving on the ball relies on the ribcage to protect internal organs during impact with the ground.
• Martial arts — a kick to the body is absorbed partly by the ribcage protecting the lungs and liver.
• Cycling — in a crash, the cranium provides the first line of defence for the brain (supplemented by a helmet).

Exam Tip: Protection questions often ask you to link a specific bone to a specific organ. Always state both — the bone AND the organ it protects. For example: "The ribs protect the lungs from impact during a tackle in rugby."

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3. Movement

The skeleton allows movement by providing a system of levers. Bones act as levers, joints act as pivots (fulcrums), and muscles provide the force to move the levers.

How Movement Works

• Muscles are attached to bones by tendons.
• When a muscle contracts, it pulls on the bone, causing movement at a joint.
• Bones cannot move on their own — they rely entirely on muscles to create movement.
• Different joints allow different types and ranges of movement (covered in later lessons).

The Lever System

A lever system has three components:

1. Effort — the force applied by the muscle contraction
2. Load — the weight being moved (e.g., the limb, a ball, a barbell)
3. Fulcrum (pivot) — the joint around which the movement occurs

flowchart LR
    A["Muscle contracts"] --> B["Pulls on bone via tendon"]
    B --> C["Bone moves at joint"]
    C --> D["Sporting movement occurs"]

    style A fill:#4a90d9,color:#fff
    style B fill:#e67e22,color:#fff
    style C fill:#27ae60,color:#fff
    style D fill:#9b59b6,color:#fff

Sporting Examples

Sporting Action	Bones Acting as Levers	Joint (Pivot)
Kicking a football	Femur, tibia	Knee
Throwing a ball	Humerus, radius, ulna	Shoulder, elbow
Jumping	Femur, tibia, fibula	Hip, knee, ankle
Performing a bicep curl	Humerus, radius, ulna	Elbow

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4. Shape and Muscle Attachment

The skeleton gives the body its shape and provides attachment points for muscles.

Shape

• The skeleton determines the overall structure and proportions of the body.
• Different body shapes (somatotypes) are partly determined by skeletal structure — for example, a person with broad scapulae and a large ribcage will have a naturally wider upper body.
• In sport, body shape affects suitability for different activities: long limbs (long femur, tibia) are advantageous for sprinting and high jump; a broad pelvis and low centre of gravity benefit stability in sports like judo.

Muscle Attachment

• Bones provide solid anchor points for muscles to attach via tendons.
• Without bones to attach to, muscles would have nothing to pull against and could not create movement.
• The shape and size of bones create ridges, bumps, and processes (protrusions) specifically for muscle attachment. For example, the deltoid tuberosity on the humerus is where the deltoid muscle attaches.