What is motor unit recruitment used for?

Motor unit recruitment is the process by which different motor units are activated to produce a given level and type of muscle contraction. At minimal levels of muscle contraction (innervation), muscle force is graded by changes in firing rate (rate coding) of individual motoneurons (MNs).

What is an example of motor unit recruitment?

Recruitment frequency is defined as the firing frequency of the first motor unit when a second motor unit is recruited. In this example, it is 12 Hz, the reciprocal of the recruitment interval, which is 85 ms. (C) With further increase in muscle strength, a third motor unit is recruited.

What happens when more motor units are recruited?

Starting with the smallest motor units, progressively larger units are recruited with increasing strength of muscle contraction. The result is an orderly addition of sequentially larger and stronger motor units resulting in a smooth increase in muscle strength.

What does motor unit recruitment depend on?

Motor unit recruitment depends on the force/resistance of the exercise. With light intensity exercise the Type I (slow twitch) motor units are recruited. When the load is increased, the Type IIa (fast twitch) will be recruited with the help of the Type I fibers.

What is a motor unit and what does it do?

The motor unit is the functional unit of muscle contraction and includes the motor nerve fiber and the muscle fibers it innervates.

What are motor recruitment patterns?

Motor unit recruitment is a measure of how many motor neurons are activated in a particular muscle, and therefore is a measure of how many muscle fibers of that muscle are activated. The higher the recruitment the stronger the muscle contraction will be.

What is the effect of motor unit recruitment quizlet?

The more weight (resistance) you add to a muscle, the more motor units you will need to recruit in order to generate movement. Recruitment stops as soon as movement starts, result is a smooth, even muscle contraction.

What does the term motor unit recruitment mean how does this influence the force generated by a muscle?

What are motor units quizlet?

motor unit. A motor unit consists of one motor neuron and all the muscle fibers it innervates or supplies.

What motor units are recruited first?

Motor units are generally recruited in order of smallest to largest (smallest motor neurons to largest motor neurons, and thus slow to fast twitch) as contraction increases. This is known as Henneman’s size principle.