Final answer:
Measuring the amount of electrical activity in a muscle can be challenging without considering certain factors. A series of action potentials is necessary for significant muscle activity, and the frequency and number of motor neurons involved also affect muscle tension. Therefore, accurately quantifying muscle electrical activity requires considering sustained contraction, graded response, and motor neurons.
Step-by-step explanation:
Muscle activity can be difficult to quantify unless certain conditions are met. One important condition is the need for a series of action potentials, or nerve impulses, to be transmitted to the muscle fibers. A single twitch does not produce significant muscle activity. Additionally, the frequency of action potentials from motor neurons and the number of motor neurons transmitting action potentials both affect the tension produced in skeletal muscle. Therefore, in order to accurately measure the amount of electrical activity in a muscle, it is important to consider the sustained muscle contraction, graded muscle response, and the role of motor neurons.