Do they routinely test back muscles during an MRI & EMG?

[Chancery]

I'm due to have an MRI and EMG some time in the distant future (I'm in the UK and our NHS has all but ground to halt other than for Covid treatment). My rheumatologist and I had words (he doesn't think I have myositis) and I wrote him a letter laying down the law about what I wanted in the way of testing (I know, what can I say? It was desperation). Trouble is, I forgot to ask him to request that they test my back muscles as those are the ones I have the most bother with.

Has anyone had an MRI or EMG - did they test your back muscles? I really don't want to write to the man again since he told me off for writing to him too much (I've now sent him a staggering total of three letters - I know the cheek of me), but I really don't want to wait 9 months for this testing only to find they test bits of me that are not particularly weak/sore and ignore the bits of me that really don't work properly. Incidentally, he is testing wiht a view to it being Dermatomyositis, hence my concern. I think maybe if he was looking for Polymyositis they would look at back muscles?

If anyone knows if they test the back muscles routinely I'd love to hear from you.

Many thanks!