My adjustments were in 2005, for chronic repetitive motion/TOS, neck strain, uneven knees, hips, ribs, shoulders etc...
Probably most of my issues go back 50 years ago when I got bucked off a horse -- concussion w/LOC.

My chiro did the atlas adjustment & checks by using leg length , hip, shoulder checks (many times per adjustment to verify).
Actual adjustment was so easy & simple..no cranking or twisting at all.. you hardly know anything happens.. other than feeling more balanced overall. For me anyway.. I was getting many other therapeutic modalities instead of just atlas adjusting..Top rib adjust, IF stim, Low level laser, ultrasound, manual trigger point work...

I know the main focused atlas guys seem to think that is the only thing needed... but I disagree.. sometimes the whole body needs work done....
Past traumas/accidents , childhood falls & such..work & postures...

He suggested drinking extra water after sessions, and after any massage, PT or body work.. It helps to flush out the junk that gets released thru the therapy..