Question

explain the roles that motor unit recruitment in summation have an increasing the force or tension of a muscle. What is occurring in a muscle organ during maximal contraction in regard to recruitment? What is occurring in a muscle cell during maximal tension during summation?

Answer 1

It is the point over the muscle,where the main motor nerve enters it.this is the point over the surface of the muscle where great densities of terminal end plates are found.At these point ,there are zones of low threshold excitability,and the skin is more sensitivity to faradic type currents.Generally,this point lies at the junction of the upper one third and the lower two third of the fleshy belly of the muscle.

Stimulation of the muscle at the motor points isolates the particular muscle,whereas stimulation of the peripheral nerve at points where they become superficial produced contraction in the muscle groups.One of the electrode connected to the negative terminal of the output socket that serve as the active electrode is used to stimulate the motor point,as the negative can depolarize the nerve with less intensity of current.The other electrode connected to the positive terminal serves as the passive electrode which is placed over the nerve trunl or plexus that supplies the muscle

The electrode can be both ped eletrodes(active and passive)made from lint pad and metal plate or carbon rubber type or one pad (passive) and one pen electrode (active) some times two pen electrode are used,one serves as active and the other serves as the passive.

A graded muscle response allows variation in muscle tension .summation occurs as successive stimuli are added together to produce astronger muscle contraction increasing the number of motor neurons involved inceases the amount of motor units activated in a muscle which is called recruitment.Muscle contraction is the activation of tension generation sites within muscle fibers.,The variables of muscle depends upon of two things i.e length and tension,