Types of Contraction

• Isometric contractions:

  • Muscles don't change length

  Isotonic contractions:

  • Muscles change length
  • Eccentric
  • Muscle lengthening under tension
  • Concentric
  • Shortening under tension
• Concentric contractions:

  • Muscle shortens
  • Joint angle decreases
  • Insertion moves towards the origin (one end of the muscle moving closer to the other)
• Eccentric contractions:

  • Lengthening
  • Joint angle increases
  • Insertion moves away from the origin
  • Muscle is acting as a brake
• Isometric contractions

  • Equal length
  • Stability
  • Stillness
  • Must be at least two muscle groups