The Skeletal System

• Five main functions of the skeleton:

  • Protection of vital organs.
  • Muscle attachment.
  • Joints for movement.
  • Storing calcium and phosphorus.
  • Red and white blood cell production.
• How does a skeleton benefit a rugby player:

  • Joints help with moving across the pitch efficiently.
  • His ribs protect vital organs if he takes blows to the chest.
  • Muscle attachment means he can use the muscles in his legs and arms.
  • Calcium and phosphorus give him stronger bones.
  • Red blood cells mean he'll have blood to go to his muscles
• Hinge joints

  • Allow only backward and forward motion.
  • There are three hinge joints: the knee, elbow and ankle.
• Pivot joints

  • Allow the bones to rotate.
  • You have three pivot joints in your body: in your wrist, elbow and neck.
  • Example: a serve in badminton or overhead shot.
• Ball and socket joints

  • When a long bone fit into a cup shaped hole, allowing circumduction.
  • The shoulder and hip joints are ball and socket.
  • An example is cricket, when you bowl you swing your shoulder.
• Condyloid joint

  • Allows circular motion but doesn't allow full circumduction.
  • The wrist is a condyloid joint.
  • A cricket player might put spin on the ball with his wrist.
• Circumduction: where the limb moves in a circle, e.g. a cricket bowl or overhead tennis serve.
• Dorsiflexion

  • Moving the foot upwards and activating the tibialis anterior (shin muscles).
• Plantarflexion

  • Moving the foot downwards and contracting the gastrocnemius (the calf).
  • Think of 𝗽𝗹𝗮𝗻𝘁arflexion as you 𝗽𝗹𝗮𝗻𝘁 your feet on the ground.
• Abduction

  • Moving your arms/legs outwards.
• Adduction

  • Moving your arms/legs inwards.
• Ligament

  • Elastic fibre that join bone to bone.
• Tendon

  • Non-elastic fibre joining muscle to bone.