Lesson 1, Topic 1
In Progress

Human body systems

The body in sport and athletics

The body is a highly complex living machine

Anatomy– The structure and organisation of the body

Itayi Vambe (Sprinter)

The body is composed of different systems:

  • Bone system
  • Muscle system
  • Nervous system
  • Digestive system
  • CardioVascular

The skeletal system

The skeletal system

The skeleton has three major functions:

  • Support
  • Protection
  • Movement.


Formed when bones fit closely together

Different types of joint allow you to move in different ways examples: 

Knee joint
This is a hinge joint, the bones can move in one direction only
Hip joint
This is a ball and socket joint, the bones can move in almost any direction.

Muscle system

Muscles are: Contractile and elastic

They work in pairs

  • Agonist
  • Antagonist

As a « muscle chain / sling »

Muscle development

In training, there should be a balanced development of a muscle (agonist) and its opposing muscle (antagonist).

 Right and left sides of the body

  • Take Off Leg vs. other leg
  • Throwing arm vs other arm

Muscles controlling movement

Inside a muscle

Bones are moved at joints by muscle

  • Contraction
  • Relaxation

Tendons at each end of the muscle attach them to bones

Your body has over 600 muscles, they allow you to

  • Move
  • Breathe
  • and even stand still

How muscles pull

Dynamic Contractions involve:

  • A change in muscle length
  • Movement at a joint or joints.
Concentric contraction,
muscle shortens and thickens to raise a load
Eccentric contraction,
muscle lengthens and controls lowering of load

Analysis of muscle action

As a coach an understanding of Anatomy helps you analyse your athlete’s movements.

Example: the muscles involved in the hurdle clearance

Extension sling : Flexion (Agonist and antagonist)

Example: prime movers involved in the running movement

Static muscle contraction

No lengthening or shortening of the muscle •No movement at the joints also known as Isometric Contractions.

On your marks position
Set position

Dynamic muscle movements

Stretch – Shortening Cycle

Muscle fiber types

In every muscle we find a mixture of muscle fibre types

  • Fast twitch fibers
  • Slow twitch fibers
  • Intermediary twitch fibers

Different people have different amounts of slow and fast twitch fibres .

•Your mixture of fast and slow twitch fibres is •

  • Fixed at birth by heredity
  • Determines the events you are suited to
  • Possibly changed by training, for some fibers.

Nervous system

Muscles pull (contract) when signals from the brain tell them to

It is composed of:

  • brain
  • spinal cord

The nervous system allows us to think and move. •It is the basis of all the actions and any learning process

Neuronal Variability

Learning “Slopes”
Skill: Motor Program