Smart gunners & armed professionals(cops PIs EP agents etc) avoid small of back & "middle of back" holsters.
If you are pushed or fall back on your firearm you can cause serious damage to your lower back/spine.
That's not fun.
That's also why cops & security officers avoid wearing handcuffs or items directly on the spine area.
Workers comp is one thing but wheelchairs are not the way to end your career.