Physiology – MCQ 88 – Factors affecting force of muscle contraction

The force of muscle contraction can be increased by all of the following except :
A. Increasing the frequency of activation of motor units
B. Increasing the number of motor units activated
C. Increasing the amplitude of action potentials in the motor neurons
D. Recruiting larger motor units

Correct answer : C. Increasing the amplitude of action potentials in the motor neurons

Action potential is an ‘all or none’ phenomenon. Increasing the amplitude beyond the threshold level does not influence the outcome.