Chronic neck pain patients were randomized to three groups, one receiving chiropractic only, one chiropractic plus aggressive exercise, and one aggressive exercise only. Of the six outcome measures, the patients were rated best in four, tied for best in one, and second in another (patient satisfaction).
Chiropractic alone finished last in all outcome categories. The study shows that adding passive modalities to aggressive exercise contributes nothing to the outcome but does add a layer of cost.