Chapter 18 Flashcards
Plyometric Exercise
Muscle reach maximal force in the shortest possible time
What is the purpose of plyometrics?
increase the power of the subsequent movements
Mechanical model
Elastic energy in the musculotendinous components is increased with a rapid stretch and the stored, immediately followed by a concentric muscle action.
SEC stands for?
Series Elastic Component
SEC
- The musculotendinous unit is stretched (eccentric)
- As lengthens, energy is stored
- Immediate concentric actions release stored energy
Neurophysiological model
Potentiation (change in the force-velocity characteristics of the muscle contractile components caused by a stretch)
Which proprioceptive organs are sensitive to the rate and magnitude of a stretch?
Muscle spindles
SSC
Stretch-Shortening Cycle
SSC phases
Phase I- Eccentric
Phase II- Amortization
Phase III- Concentric
Phase I- Eccentric
action: stretch of the agonist muscle
physiological event: elastic energy is stored in the series elastic component. Muscle spindles are stimulated.
Phase II- Amortization
Action: pause between phases I and III
Physiological event: type Ia efferent nerves synapse with alpha motor neurons. Alpha motor neurons transmit signals to agonist muscle group.
Phase III- Concentric
Action: shortening of agonist muscle fibers
Physiological event: Elastic energy is released from the series elastic component. Alpha motor neurons stimulate the agonist muscle group
limit maximal height for depth jump
1.2 m
The recommended height for depth jump
41 to 107 cm
the norm height for depth jump
76 to 81 cm
