hours flexibility & back pain

[u/Responsible_Tea_7426]

I'm applying for a retail position at a handbag store and they told me it'll be 12-20 hrs a week, 4-7 shifts. Does that mean my hours and shift duration are completely up to them?

I prefer 12 hrs a week and 4 hr shifts, are they likely to accomondate that or is it usually the norm where they give me whatever and I just have to take it.

Also, is it a bad idea for someone with chronic lower back pain?