Types of Muscular Contractions

Introduction

• There are three main types of muscular contractions:
  • Isometric
  • Concentric
  • Eccentric
• Important for exams to understand these distinctions.

Concentric Contractions

• Definition: Muscle shortens as it contracts.
• Purpose: Used to accelerate an object or the body.
• Examples in Sport: Movements like jumping, kicking, running, throwing, lifting, tackling, shooting, heading, and driving involve concentric contractions.
• Commonality: Most common type of contraction in sports as they involve moving or accelerating something.
• Example: Bicep curl involves concentric contraction when lifting the weight.

Eccentric Contractions

• Definition: Muscle lengthens under tension to decelerate an object or oneself.
• Key Point: Different from stretching as the muscle is under tension.
• Examples in Sport: Used when landing from a jump or during the lowering phase of exercises like squats and push-ups.
• Acronym to Remember: "Eccentric to Earth" - lowering phase is controlled to prevent quick impact.
• Function: Controls the rate of descent, preventing collapse.
• Commonality: Less common than concentric contractions.

Isotonic vs. Isometric

• Isotonic Contractions include both concentric and eccentric.
  • "Iso" means same, "tonic" refers to tension or speed.
• Isometric Contractions
  • Definition: Muscle contracts without changing length.
  • Examples in Sport: Holding positions like a gymnastic crucifix or a sprinter's set position.
  • Commonality: Rare in sports as they involve being stationary or in a fixed position.
  • "Iso" means same, "metric" relates to length.

Summary

• Concentric: Accelerating or moving.
• Eccentric: Decelerating or lowering under control.
• Isometric: Holding a position without movement.

Exam Tip: Understanding these types of contractions and their applications in sports will help answer related exam questions effectively.