The scope is attached to either cylinder and I get the muscle vibration at 1 KHz but with no scope attached I can't feel anything so what is going on?

Oscilloscopes generate their own impedance which gets added to the original signal. You might want to see:
https://learn.sparkfun.com/tutorials/how-to-use-an-oscilloscope

Especially:
"Input Impedance – When signal frequencies get very high, even a small impedance (resistance, capacitance, or inductance) added to a circuit can affect the signal. Every oscilloscope will add a certain impedance to a circuit it’s reading, called the input impedance. Input impedances are generally represented as a large resistive impedance (>1 MΩ) in parallel (||) with small capacitance (in the pF range). The impact of input impedance is more apparent when measuring very high frequency signals, and the probe you use may have to help compensate for it."

In other words, disconnect the scope before you run the signals through your muscles. The extra variance from the oscilloscope will produce unwanted effects. One of my favorite channels on Youtube explaining similar topics is Ludic Science:
https://www.youtube.com/channel/UCM014DFZ7peFVrSaxnh4-Mw

If you would use a current meter then would know how this "feeling of a muscle vibration" relates to the current that is flowing through you.

For more details, please check the link:
http://www.spooky2.com/forums/viewtopic.php?f=12&t=5614