Hi Spyros,
I have had patients who were unable to even do elbow flexion and at the same time finger flexion for a month or two but with tapping and stimulation of the affected part done intensively during therapy sessions it will provide you with good results, sometimes you have to vary the position and not just stick to one.. others will also have no intiation at the beginning of the range but at the midrange or end-range of elbow flexion ( or any other ROM) you will get a contraction... and of course a STRONG command of instruction produces REALLY GOOD RESULTS. I guarantee you that. Been doing it for 3 years now hahaha!!! Usually I notice that patients do not respond to voices that are not loud enough. Mine works all the time...Goodluck to you!!!
Regards,
Charlize29