As you get older (and shorter, your ribs can end up under you hip crests If they rub there, you can get serious back pains referring to buttocks/hips. This can activate spasm in your back quadratus lumbori and buttock piriformis which creates a new pain life all its own as it did in my case.
A simple belt can hold ribs in so they don’t rub on hip (iliac) crests
Use of Rib Compression Belt for Pain in Osteoporosis
Gerald G. Hirschberg et al
Orthotics and Prosthetics 39(2) 75-79, 1985
http://www.oandplibrary.org/op/pdf/1985_02_075.pdf
demonstrated no rubbing after:
Harbinger makes a narrow belt which you can get on amazon:
