So I just had this wild thought occur to me.
The TENS Twin-Stim muscle stimulator is a programmable device which can be programmed for constant pulses ranging from 2 Hz - 150 Hz with variable wavelengths and stim durations.
I think it might be possible to connect this type of machine up to your right and left forearms to create a slight, constant, involuntary wrist-jacking motion for enhancing long-jack / chordjack performance on 4 key files.
For example, jackhammer madness has 200 bpm 16th note long jacks. So if you could set the machine to a 13.33 Hz pulse frequency with a 200-300 microsecond wavelength (200 bpm x 4 notes per beat / 60 sec per min = 13.33 Hz), so that you achieve a slight involuntary wrist-jack motion of 13.33 notes per second, then you could - hypothetically - greatly enhance your performance on this file.
Furthermore, this type of involuntary wrist-jacking motion could be tuned to lower intensities to boost stamina recovery, and generally increase stamina overall during a session.
Has anyone ever experimented with this type of performance enhancement before? Thoughts?
Edit: I suppose one downside is that the machine can only be adjusted in 1 Hz steps. Therefore, you wouldn't be able to achieve a perfect 13.33 Hz frequency, and would have to settle for a rounded 13.00 Hz. Furthermore, it may be difficult to synchronize the EMS waveform with the down-beat of a given file. Also, it might not be possible to use this effectively on files with highly variable bpm changes.
One of the major benefits with this machine is that the involuntary muscle stimulation would be synchronized between the left and right arms, allowing for efficient jump/quad jacking, and better control with two-handed patterns in general.