Chiropractic is a form of alternative medicine whose main principles focus on the re-alignment of the vertebrae of the spine to restore normal biomechanical motion and function to regions of the spine. The way chiropractors restore this biomechanical motion and function is through the chiropractic adjustment. There are several ways for chiropractors to give this chiropractic adjustment, the most common being a hand adjustment. With this type of adjustment, the chiropractor locates the misaligned vertebra and provides a specific thrust or push with his or her hand to ultimately "correct" that specific misalignment. When it is corrected, a crack-like noise is generally heard which most have come to know and associate with chiropractic.