It depends, mg. All are theoretically trained to, but many do not these days. The doc I went to previously did the old school type of hard, cracking and quick adjustments, which worked, but weren't all that comfortable or long-lasting and only took about 15 minutes, at the most. The one I go to, now, my friend, was trained in a softer, deep muscle/bone approach which lasts longer and is more subtle. To do it correctly takes an hour to 1.5 hrs. Most docs won't spend that kind of time any more as the cost of doing business rises and/or they get greedy. I will still recommend seeing one, regardless, as any adjustment they do can be helpful.