"Chiro" comes from the Greek word "kheir," which means "hand," and "practic" from the Greek word "pracktikos," meaning practice. Chiropractic is a form of complementary-alternative medicine (CAM)   focused on treating spinal and musculoskeletal problems primarily through manual manipulation. A chiropractor does not prescribe medication but relies on a variety of manual therapies, including manual manipulation and mobilization, and adjunctive therapies, to improve function and provide pain relief.  It is based on the manipulative treatment of joint misalignment, especially those of the spinal column.   Manipulation is used to restore mobility to joints restricted by tissue injury caused by a traumatic event, such as falling or repetitive stress. 

History 
Spinal manipulation is one of the oldest healing practices, first described by Hippocrates in ancient Greece. In 1895, Daniel David Palmer founded the modern chiropractic profession in Davenport, Iowa, and it arose as a separate profession in the United States.  Until the 1950s, the profession was concentrated in North America and largely isolated from the mainstream health care. In the 1960s and 1970s, the foundations were laid for broader acceptance of the profession – improved educational and licensing standards, significant research, research texts and scientific journals, and legal recognition and regulation in all US states and Canadian provinces,  and various other countries.  Today, more than 100 years after its birth, chiropractic is taught and practiced throughout the world, and the profession has earned broad acceptance from the public and in national health care systems for its services. It is the leading example of a complementary-alternative health care discipline reaching maturity and mainstream acceptance. Doctors of chiropractic recognize the value and responsibility of cooperating with other health care practitioners when in the patient's best interest.  In 2005, the World Health Organization (WHO) published the Guidelines on Basic Training and Safety in Chiropractic, recommending educational standards for recognizing and regulating chiropractic services within national health care systems of all member countries.  The World  Federation of  Chiropractic (WFC) has been a non-governmental organization in official relations with the WHO  since 1997,   and collaborates with many federations representing other healthcare professions. The WFC website provides detailed information about all aspects of the profession. The chiropractic profession is regulated in all US states by state boards and all Canadian provinces by provincial colleges. These regulatory bodies are established by legislation in the same manner and with the same structure and similar regulations as the regulatory bodies for other healthcare professions. They are responsible for protecting the public, setting practice standards, maintaining quality care,  evaluating and promoting competency, and handling disciplinary issues. Refer to the Federation of Chiropractic Licensing Boards (FCLB) directory for a list of all chiropractic regulatory boards. 

Practice
The chiropractic practice is recognized and regulated by law in approximately 40 countries. In many other countries where the profession is established, it is recognized and legal under general law. Standard features of legislation and practice in all jurisdictions are:

1) Primary care - direct contact with patients

2) No use of prescription drugs or surgery 

3) The right and duty to diagnose, including taking and/or ordering diagnostic imaging   (X-ray & MRI)

The chiropractic practice focuses on the relationship between structure (primarily the spine) and function (as coordinated by the nervous system) and how that relationship affects the preservation and restoration of health. The  WFC defines chiropractic as  "A health profession concerned with the diagnosis, treatment, and prevention of mechanical disorders of the musculoskeletal system, and the effects of these disorders on the function of the nervous system and general health. There is an emphasis on manual treatments, including spinal adjustment and other joint and soft-tissue manipulation." Chiropractic adjustment/manipulation is referred to as spinal manipulation when applied to joints of the spine  (vertebrae).   The common goal of most chiropractic treatments is to restore or enhance joint function, with the general goals of resolving joint inflammation and reducing pain. Some approaches use force, while others are more gentle (joint mobilization). 
Chiropractic Manipulative Treatment (CMT), also known as a chiropractic adjustment or spinal manipulation, is a hands-on therapy involving the controlled application of force to a joint to restore its normal movement and alignment. Its primary goals are to reduce nerve irritation, improve range of motion, and promote the body's natural healing process. CMT refers to a chiropractor manipulating skeletal joints, particularly spinal segments (i.e., the joint between each vertebra) that have abnormal movement patterns or fail to function normally. The objective of CMT is to correct structural alignments of the joints and spinal segments (subluxations),  with the goals of increasing range of motion, reducing nerve irritability, and improving physical function.  Chiropractors use different manipulation techniques in practice. These techniques may include varying levels of biomechanical force, ranging from high-velocity, low-amplitude (HVLA) to low-velocity, low-amplitude (LVLA). Some chiropractors only perform joint manipulation with their hands, while others use various instruments (e.g., activator). Some may also use specialized tables like the one for the Cox® Flexion-Distraction technique. Additionally, some chiropractors treat using quick but firm manipulation,   while others have a lighter touch. The original chiropractic adjustment approach, which is generally referred to as the diversified technique, is an HVLA  thrust, and  typically involves:

1) A high velocity, short lever arm thrust applied to a vertebra. 

2) Might be accompanied by an audible release of oxygen, nitrogen, and carbon dioxide  (joint space cavitation).

3) A relieving sensation, although minor discomfort has been reported (usually lasting for a short duration) if the surrounding muscles are in spasm or the patient tenses up during chiropractic manipulation.

Joint mobilization is a type of passive movement of a skeletal joint. It is the careful use of skilled graded forces to move a skeletal joint in a desired direction to achieve a therapeutic effect.   Chiropractors, osteopaths, physical therapists, and occupational therapists often use these techniques.   It is referred to as spinal mobilization when applied to the spine joints (spinal segments). The goal of spinal mobilization is the same as HVLA spinal manipulation - to restore or to enhance joint function. However, unlike HVLA spinal manipulation, slow movement, usually to a firm endpoint of joint movement, is used to mobilize the joint. Chiropractors may choose spinal mobilization for certain patients for a variety of reasons, such as:

1) Patient preference - certain patients prefer spinal mobilization over spinal manipulation
2) Patients with sensitive nervous systems may benefit from gentle chiropractic techniques to keep the body from overreacting and causing reactive muscle spasms
3) Patients with some conditions may be contraindicated for spinal manipulation, such as patients with advanced   osteoporosis, bone pathology, some forms of deformity, and certain types of inflammatory arthritis
4) Chiropractors may choose spinal mobilization for patients when they are in the acute stage of their condition and in severe pain
5) Obesity can make the patient's positioning and manipulation procedures challenging for both the provider and the patient, which might favor a low-force technique.   

Chiropractic care represents a safe and effective treatment alternative for older adults. retrospective cohort study in older adults with a neuro-musculoskeletal complaint evaluated the risk of injury to the head, neck, or trunk following an office visit for chiropractic spinal manipulation, compared to an office visit for a primary care physician evaluation. Among Medicare beneficiaries aged 66–99 with an office visit risk for a neuro-musculoskeletal problem, risk of injury to the head, neck, or trunk within 7 days was 76% lower among subjects with a chiropractic office visit than those who saw a primary care physician. Here is my graduation paper on Chiropractic Treatment for Geriatric Patients. Veritas Health Publication's Chiropractic Health Center and Video Library offer unbiased, high-quality resources for patient education, empowering people to make informed health decisions.