1. The eccentric phase consists of stretching the agonist (prime mover) muscle.
2. The amortization phase is a short pause between the eccentric and concentric movements.
3. The concentric phase involves the shortening of the agonist (prime mover) muscle.
An easy to understand example of this is the long jump. While the individual runs into the actual jump, the foot touches down and the gastrocnemius is stretched (the eccentric phase), there is a short delay in movement (the amortization phase). The gastroc then platar flexes at the ankle joint (the concentric phase), and propels the athlete vertically and horizontally.
Typical lower body plyometric exercises are repeated jumps in place, jumps with rest, multiple hops and jumps (covering a distance), bounds, box drills, or depth jumps.
Upper body plyometrics are more difficult to utilize, and the main exercises are throws (usually a medicine ball), catches, and push up variations.
