Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.
Chiropractic's origins lie in the folk medicine of bonesetting, and as it evolved it incorporated vitalism, spiritual inspiration and rationalism. Its early philosophy was based on deduction from irrefutable doctrine, which helped distinguish chiropractic from medicine, provided it with legal and political defenses against claims of practicing medicine without a license, and allowed chiropractors to establish themselves as an autonomous profession. This "straight" philosophy, taught to generations of chiropractors, rejects the inferential reasoning of the scientific method, and relies on deductions from vitalistic first principles rather than on the materialism of science. However, most practitioners tend to incorporate scientific research into chiropractic, and most practitioners are "mixers" who attempt to combine the materialistic reductionism of science with the metaphysics of their predecessors and with the holistic paradigm of wellness. A 2008 commentary proposed that chiropractic actively divorce itself from the straight philosophy as part of a campaign to eliminate untestable dogma and engage in critical thinking and evidence-based research.
The treatment plan may involve one or more manual adjustments in which the doctor manipulates the joints, using a controlled, sudden force to improve range and quality of motion. Many chiropractors also incorporate nutritional counseling and exercise/rehabilitation into the treatment plan. The goals of chiropractic care include the restoration of function and prevention of injury in addition to back pain relief.