Antagonistic Muscle Action

• • Agonist - prime mover - muscle that causes movement
  • Antagonist - muscle that relaxes to allow agonist to contract
• MUSCLE PAIRS

  • Biceps and triceps.
  • Latissimus dorsi and pectorals - adduction and abduction at shoulder
  • Tibialis anterior and gastrocnemius - dorsiflexion and plantarflexion at ankle
  • Hip flexors and glutes - flexion and extension at hip
  • Quadricep and hamstring - extension and flexion at knee
  • Rotator cuffs and deltoids
• MUSCLE CONTRACTION

  • Isotonic and isometric contraction
  • Two types of isotonic contraction - concentric and eccentric
  • Concentric - muscle shortens as it contracts
  • Eccentric - muscle lengthens at it contracts - always downwards movement
  • Isometric - muscle contracts but stays same length - fixed position
• SPORTING EXAMPLES

  Concentric

  • Upward phase of bicep curl, sit up, push up
  • Hamstring curls
  • Take off phase of a jump

  Eccentric

  • Downward phase of bicep curl, sit up, squat, lunge

  Isometric

  • Holding plank position
  • Stand in gymnastics
  • Starting blocks
  • Crucifixion