Types of Resistance Action

• Isotonic  
  The muscle either shortens or lengthens while it is producing tension. Isotonic contractions can be identified as either concentric (motive force) or eccentric (resistive force) contractions. Isotonic is the most used type of muscular training.
  
  
• Isokinetic   
  Pertaining to an exercise providing variable resistance to a movement at a constant speed, with the assistance of specialized equipment.  Isokentic devices control angular velocity and thus match resistance with the exact amount of force applied by the user to achieve a given velocity -- little force applied, little resistance returned.
  • Biodex (Definition and brief history of device)
  • Biodex Dynamometer Machine (see the "Technology" tab below the picture of the Biodex)
     
    
• Isometric 
  No movement just mechanical tension.