Hi Arun,
you must be knowing that, passive stretching is a strict NO NO in myositis ossificans, though you have been doing hold relax which is a alright thing to do... you also mentioned about doing passive stretching which according to me you have to STOP immediately.... its going to worsen the condition.... i would suggest you to start IONTOPHORESIS, if i am right i think you should try with acetic acid ! try to refer to some literature about the dosage... otherwise continue with active movements only but no massage or stretching .... cheers