Hi David

There can be lots of reasons for being assymetrical - everything from occupational (you are in an occupation where you use one muscles more so than the other, anatomical (nature gave you different sized muscles or are missing a muscle or part of a muscle) to pathological (there is some disease or injury that accounts for muscle weakness or a nerve problem.

If you are worried about it I would get it checked out to see if the muscle is ok.

would electrical stimulation work? On the whole no. Electrical stimulation (you stimulate the motor nerve that supplies the control to the muscle) is good when there is a really marked pathology of the nervous system such as if you had a stroke, or another disease that has caused paralysis, or serious injury to the muscle that has caused it to really stop working. properly. It works when the weakness is very very marked. This would not be likely in your case. If you are able to work against weights - even if there is considerable difference between sides then you are too good for electrical stimulation.

You would be much better off doing progressive resistance training in the gym. You could get a trainer to give you a comprehensive exercise programme to target the muscle