Final answer:
The unfused tetanic force can vary among motor unit (MU) types depending on factors such as the type of muscle fibers and the number of motor units recruited.
Step-by-step explanation:
The unfused tetanic force among motor unit (MU) types can vary. An unfused tetanic force is the force exerted by a muscle that has not reached complete tetanus. Incomplete tetanus occurs when the stimulus frequency is high enough that contractions become continuous with short relaxation phases. Complete tetanus occurs when the stimulus frequency is so high that the relaxation phase disappears completely. In general, the force generated by different MU types during unfused tetanic contractions depends on factors such as the type of muscle fibers and the number of motor units recruited.