There is a place at the top of Rua Xelmirez, on the right, that offers a very nice foot and leg massage service. it is called Step Inn SCQ, and is located as Rua Xelmirez #32.
If you use Facebook, hit them here:
https://www.facebook.com/StepInnScq/
If not, I think you are out of luck. I cannot find a website.
Their phone number is listed as: +34 673 66 98 52
Hours are listed as: 11:00 to 20:00, apparently over seven days. (UPDATE: another member pointed out they are apparently closed on Sundays...normal for a service business in Spain...)
There are likely other places, but this is the most centrally located one I am aware of.
This is just past Rua Nova, on the right, as you start going up the hill.
Hope this helps.