I found a good number of studies investigating the effects and practice of "knuckle cracking", but close to none on other sites of joint cracking/popping. knuckle cracking appears to be safe, but i don't know if the statement can be extended to other joints.
These are some of the papers i found, and they all refer to the habit of cracking one's knuckles:
https://pubmed.ncbi.nlm.nih.gov/36454151/
https://pubmed.ncbi.nlm.nih.gov/30080300/
https://pubmed.ncbi.nlm.nih.gov/28050816/
https://pubmed.ncbi.nlm.nih.gov/21383216/
Only the first paper mentions in passing "severe joint cracking of his knuckles and, at times, his back."
To clarify, i'm mostly interest in the habit of self-cracking, like one would do with their fingers, which has been found to have no ill-effects.
Is there any such evidence on back-cracking? habit of self-joint cracking in general
to clarify further: i'm not interested in chiropractice or their "techniques"