Answer:
True.
Step-by-step explanation:
Particularly skeletal muscles contraction are controlled by moton neurons by action potentials. The contraction of muscles which are neurogenic can be describes as summation, twitch, or tetanus, it depends on the action potential frequency.
In simple words, our nervous system generates a signal in the form of impulse which travels by action potential through a nerve cell called motor neuron. This signal causes the contraction of muscle fibers and when this signal terminates the muscle fibers come back to normal relax position.
So, its true that the force of muscle contraction is controlled by multiple motor units summation or recruitment.