Most people do not realize chiropractors do not all adjust the spine the same way.
Some Chiropractors use instruments and some are by hand only. The best Chiropractors will incorporate a combination of both.
When it comes to the manual adjusting you should avoid rotational adjusting techniques. The spine will heal up so much faster if it is not rotated. A good non rotational adjusting technique is called Gonstead Adjusting.