This may happen, just make sure the neg leads are towards to top of the hamstrings and that the whole area is flooded (contracted) you may need to play with pad position a bit more.
I can’t comment on the specific unit you’re using as I haven’t seen it.
What specifically is “uS pulse duration 300”? Are we talking about pulses per second? I think Charlie advocates a minimum of 20 hz which will apparently put the muscle into tetanus. In working with EMS myself for increases in strength and power I attempt to take as much voltage at the highest frequency possible. With the ARP that would be 2.5 watts at 500 pps. When the ARP is applied to healthy tissue the above maximum setting is tolerable for most athletes. When we’re talking about “unhealthy” or injured tissue (rehab) these settings are very tough to tolerate unless your very determined (like me!).
All stims are a bit different as are the people they treat. you can’t have a blanket rule for the amt of current. the more FT fibre and less fat an individual has, the less current it takes to get a max contraction.
Most galvanic and/or interferential units will cause the sort of spastic contractions I think your referring to. One of the reasons its’ tough to use EMS actively (joint in motion) vs. passively. One of the benefits of the ARP is that the body’s natural resistance to the waveform “drops out” making joint movement possible. I get virtually no spastic, uncoordinated contractions with the ARP even when cranked up to 4 watts (I thought maximum output was 2.5 watts previously) and 500 pps. I know this info. does’nt due you any good. Addressing your terminology, all contractions stimulated through EMS are, or course, involuntary. I assume you are referring to an uncoordinated spastic type of response.
I’m hoping someone smarter than I can educate me. The ARP specifies output power in watts (maximum output power 4 watts). How do watts compare with microamps, volts, etc. I’m trying to determine how powerful nap’s unit is relative to the ARP and my lack of electrical engineering background makes this difficult. Can anyoune help me out here?