Which factors Contribute to Force Production? (Part 1)

force_combined

 

Research has shown that there might be 4 factors that contribute to muscle production:

1) Muscle Mechanics

2) Morphological factors

3) Neural Factors

4)Muscle Environment

I will try to go a little bit dipper to each one of them. On this part I will focus on Muscle Mechanics.

1) Muscle Mechanics

1.1 Force Velocity Relationship

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For individual muscle fibers, muscle force and contraction velocity are inversekly related. When high levels of force are required, the contraction velocity is low. On th eother hand, when high velocities are required, the force produced is lower.

This can be explained in part due to the time for actin-myosin interaction, as well as all the inherent neuromuscular physiological mechanics to take place. Faster Contraction velocities shorten the time available, which will reduce the potential for the number of action and myosin crossbridges.

1.2 Length Tension Relationship

length-tension-relationship

For individual muscle fibers, these appears to exist an optimal balance between the relative position of the sacromere and the force it can therefore produce. Greater than optiamal sacromere length (c) reduce the potential for force production, as well as shorter than optimal sacromere length (a). A morebalanced lengthenables an optimal number of actin-myosin crossbridges, allowing a greater potential for force production (b).

1.3 Type of Muscle Action

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Daily  and sports action inlove almost exclusively some sort of Stretch Shortening Cycle (SSC). In other words, almost all actions have an eccentric portion, a transistion of isometric portion, and a concentric portion. When using a SSC, it enables greater force production through:

  • Greater time to produce force
  •  Storage and utilization of elastic energy
  • Interaction of contractile and elastic elements
  • Potentiation of contractile and elastic elements
  • Stretch reflexes