Throughout chiropractic 's history, the profession has conducted clinical research despite limited funding. Chiropractic does not use implantable medical devices or pharmaceutical drugs, so it has not received research funding from device or pharmaceutical companies, unlike conventional medicine. Most chiropractic colleges have self-funded their research programs with support from chiropractic foundations.
Federal support for chiropractic research began in 1992 with the establishment of the National Center for Complementary and Integrative Health  (NCCIH) of the National Institutes of Health.
The majority of clinical research in chiropractic has focused on its effectiveness in caring for spine-related injuries and complications from spinal stress. These studies have focused on the most common complaints treated in chiropractic offices: low back pain , neck pain and headaches , and peripheral nerve problems. The studies usually compare a typical chiropractic regimen with commonly utilized pharmaceuticals, or combinations of therapies. Any lasting effects of treatment are measured over time.
The major studies have found clinical benefit to the participants from chiropractic treatment, some showing superiority of short and long-term effects.
Here are three examples of analyses of pools of research:
It is far easier to study chiropractic as a treatment than as an approach to wellness. When a patient has a specific complaint that can be measured by level of pain or certain limitations, different interventions can be compared in their ability to affect changes. But how does one measure wellness?
This is one of the elusive issues in research. What should the measures be and how does one control for the confounding effects of daily living? The currently accepted standard of sound clinical research is the randomized controlled trial, but in order to study wellness, other approaches will need to be devised and validated. Because of these issues, there is little research on the preventive effects of chiropractic.
To find studies on the use of chiropractic and other alternative approaches, such as acupuncture  for specific conditions, go to PubMed  and conduct a search, using both the word chiropractic and the name of the condition. The National Center for Complementary and Alternative Medicine supports a CAM search engine for PubMed publications .
ClinicalTrials.gov , the National Institutes of Health website devoted to current clinical trials, lists several chiropractic trials that are currently recruiting patients for major studies.