Muscle Stim and Ultra Sound

I have access to a Muscle stim and Ultra SOund Machine and Ice Tank at any time. I was wondering when I should use them and for how long? Can the muscle stim machine be used to help strengthen my hamstrings?

I am a 100m and 200m sprinter.

All tips and and suggestions would be greatly appreciated.

Thanks

How did you manage that? You work/volunteer in a clinic/hospital?

I managed to go to school

cool…med school?