crashbreaka

Oct 22 2012, 06:45 AM

Only if you believe in that kind of thing. Scientifically you body moves from signals coming from your brain which cause your muscles to contract.

Sometimes I feel like the nerd of DBZF

Tim

Oct 22 2012, 07:29 AM

crashbreaka

Oct 22 2012, 06:45 AM

Only if you believe in that kind of thing. Scientifically you body moves from signals coming from your brain which cause your muscles to contract.

Sometimes I feel like the nerd of DBZF

Trust me, i'm the nerd.

Short Summary on how your muscles work

Voluntary movement is coordinated by the brain (Purves, 2012). This is initiated by the upper motor neurons of the motor cortex and brainstem which provide spatiotemporal sequences of skilled movements and appropriate orientation respectively (Purves, 2012). These neurons also receive stimulus from the cerebellums efferent pathways which, after detecting the level of error between intention and action, act to mediate this (Purves, 2012). The axons of these upper motor neurons descend to the ventral horn of the spinal cord or the brainstem (the motor nuclei of the cranial nerves) where they terminate with the cell bodies of the lower muscle neurons; lower muscle neurons are innervated by this in additional to stimulus from sensory input (Purves, 2012). The lower muscle neurons are what directly causes movement (reflexive or voluntary) of a muscle (Purves, 2012).

The motor unit refers to a single α motor neuron (a type of lower muscle neuron) as well as the muscle fibers associated with them, and this is the smallest unit of force that can activated to produce movement, although the exact amount of muscle fibers innervated by one motor unit can vary (Purves, 2012). It is this process that causes the striated extrafusal fibers to contract and generate the force required (Purves, 2012). The total amount of force provided depends on the number of motor units recruited; this occurs in a certain order based on the size of the motor units (Purves, 2012). This works through the different motor unit types with the lower threshold slow (S) motor units being recruited first, followed by fast fatigue-resistant (FR) motor units as the synaptic input increases until finally the fast fatiguable (FF) motor units are recruited to provide the largest amount of force - this is known as the size principle (Purves, 2012).

The rate of action potential firing also contributes to the regulation of force within the muscle (Purves, 2012). If a muscle fiber is activated by a subsequent action potential before it has had time to completely relax we will see a summation of the overlapping contractions, increasing the force applied (Purves, 2012). This works through residue calcium still remaining in the muscle as it has been unable to return to the sarcoplasmic reticulum allowing for a summation of calcium ions to increase the strength of contraction (Purves, 2012). As we get an increasing number of action potentials overlapping this increase in force grows until the muscle fiber reaches a state of fused tetanus (Purves, 2012). This is a stage at which the force provided no longer modulates and forms as the twitches are all fused (Purves, 2012). However under standard conditions this firing rate cannot be reached (Purves, 2012).
Muscle spindles are an important part of sensory feedback of muscle stretching (Purves, 2012). These spindles run in parallel to the extrafusal fibers of the motor units and are made up of the nuclear bag and nuclear chain intrafusal fibers (Purves, 2012). Each muscle spindle contains some central nuclear bag fibers which are wrapped in group Ia afferent axons which, along with the group II afferent axons on the nuclear chain fibers help provide quick reflex adjustments when the muscle stretches (Purves, 2012). The final part of the modulation of the muscle spindles is the γ motor neurons which cause the intrafusal fibers to contract and allow the discharge in the afferent fibers to remain appropriately proportional to the muscle stretch (Purves, 2012).

There are however numerous ways you can amp up your muscles. For example, provide electrical stimulation can cause a muscle to reach what is called tetanus which causes a much stronger contraction than you could have done stimulating the muscle voluntarily.

The idea of 'ki' could well be based on something like this - so who knows really