File under general - general
We have to say at the outset that we are not experts in electroacupuncture. Although a significant minority of our members do use EA machines we ourselves only train in traditional acupuncture with manual stimulation, and the kinds of sophisticated instruction in how best to use the machines is not a part of our training. You might find that the Acupuncture Association of Chartered Physiotherapists might be more helpful in that respect because its members more regularly use these machines as an adjunct to their work.
We have looked carefully at the major textbook on electroacupuncture, David Mayor's authoritative volume published a decade ago, and there are no cautions about the use of EA on scar tissue, nor any reports of muscle tearing after EA treatment. We have also conducted a very thorough search of all the databases on adverse events after acupuncture treatment, and there have been no case reports of this kind.
This is not to say that anyone could categorically say that it can't happen; anything is possible and there has to be a first times for any adverse event to happen. However, given the vast extent of the use of EA in China and the Far East we would have expected there to be some mention of any similar adverse events, and there is none.
We are not sure whether your question is an general one or a question based on something which has happened to you. All we can suggest if it is the latter is to go to the professional association to which the practitioner belongs and ask for the matter to be investigate and possibly passed on to their professional insurers if you have suffered any detriment after treatment.
We are sorry that we cannot be more helpful, but as we say, this is not really our field of expertise.