Answer the question about text:

Our assignment was to dial up the electric stimulation and measure how high the current needed to go at a given frequency in order to establish sensory threshold ( when you first begin to feel a tingle ) and motor threshold ( when muscles first begin to twitch ) . We started with 2 Hz which is two pulses per second . Then we delivered 25 Hz or 25 pulses per second . Finally , we went up to 100 Hz or 100 pulses of electrical stimulation per second .

What may be the reason for their testing ?
They were required to do so for an assignment .