EHS 230 Lecture Notes - Lecture 10: Pinnation, Hockey Puck, Myocyte
19 Jun 2018
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Lecture 11
Biomechanical factors in human strength
Neural control
- Recruitment- motor units in contraction
- Rate coding- rate motor units are going at
- Neural adaptations – responsible for muscle increase in 1st weeks of lifting
-slows down afterwards
Muscle cross sectional area
- Force muscle produces depends on cross sectional area
- Tall athletes have more muscle volume but short athletes can develop volume
too
Muscle fiber arrangement
- Pennation angle- angle in between muscle fiber and line b/w origin and insertion
- Pinnate muscle- soft looking construction of fibers
-increases muscle force production and contraction at high speed
- not good for eccentric, isometric or contraction at small speed
Force to velocity relationship
- In concentric and eccentric activation
-muscle’s contraction rate depends on its max production of force
- when a muscle’s velocity of concentric contraction rises the possible force that it
generates decreases
Ex. Hitting an air hockey puck
- If eccentric contraction velocity rises, the force that the muscle may produce
increases too
- Force and velocity are proportional
Ex. Kicking a soccer ball or throwing a football
- Force velocity curves show how concentric and eccentric contractions affect the
force produced
- The most force produced is based off on eccentric exercises
- Muscle length- resting muscle can generate more force because actin and
myosin are at good position to contract
Strength to mass ratio (power to weight)
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Neural adaptations responsible for muscle increase in 1st weeks of lifting. Force muscle produces depends on cross sectional area. Tall athletes have more muscle volume but short athletes can develop volume too. Pennation angle- angle in between muscle fiber and line b/w origin and insertion. Pinnate muscle- soft looking construction of fibers. Increases muscle force production and contraction at high speed. Not good for eccentric, isometric or contraction at small speed. Muscle"s contraction rate depends on its max production of force. When a muscle"s velocity of concentric contraction rises the possible force that it generates decreases. If eccentric contraction velocity rises, the force that the muscle may produce increases too. Kicking a soccer ball or throwing a football. Force velocity curves show how concentric and eccentric contractions affect the force produced. The most force produced is based off on eccentric exercises. Muscle length- resting muscle can generate more force because actin and myosin are at good position to contract.
