Not sure what cytochrome oxidase has to do with myositis diseases. It is a protein that is essential in respiration. The muscle weakness that is typical of myositis are in the proximal muscles, those off your trunk. Symptoms are difficulty getting out of chairs, going up stairs, raising your arms , and swallowing.
Polymyositis primarily hits those proximal muscles and dermatomyositis can be less severe on proximal muscles and and also hit the distal muscles. A third type of myositis, IBM, is less severe at presentation but progressive and untreatable. The myositis site will give you more information but from the little that you have described it does not sound like you have myositis.
Did your doctor do blood tests? Was your CPK or SED rate elevated? A biopsy will usually show if you have myositis and what type but not always depending on the activity or meds at the time of the biopsy.
Mixed connective tissue disease (systemic lupus, scleroderma, polymyositis), Raynauds phenomena, Hypertension, Barrett's esophagus.
Meds: prednisone 5mg, 50mg imuran, Lotrel 40/5mg, maxide 37.5/25mg, folic acid, potassium, aciphex 20mg, multi vitamins.
Maintain your optimism and you can beat the odds.
"Although the world is full of suffering, it is also full of the overcoming of it." Helen Keller