What is occurring between the threshold and the maximum cont

What is occurring between the threshold and the maximum contraction? Explain the relationship of increasing voltage stimulation to the recruitment of motor units.

Solution

What is the occurring between the threshold and maximum contraction?

Between the threshold and maximum contraction; as the stimulus is increased above threshold into a range called submaximal stimuli, contraction strength will increase with increasing stimulus intensity; as progressively more and more muscle fibers in the muscle undergo contraction, till the stimulus strength is at the (maximal); all muscle fibers in the muscle are contract.

Relationship between increasing voltage stimulation and the recruitment of nerve fibers.

As we increase voltage stimulation this leads to increased Motor unit recruitment and this increases to a point until a plateau is reached i.e. saturation occurs. Thus as the stimulus amplitude continues to increase, an increasing number of motor units will be recruited so that the strength of the contraction, or tension, increases as well. Once all motor units in a muscle have been recruited, an increase in the stimulus amplitude will not result in any increase in tension.