Physical therapy or physiotherapy (sometimes abbreviated to PT) is a health care profession primarily concerned with the remediation of impairments and disabilities and the promotion of mobility, functional ability, quality of life and movement potential through examination, evaluation, diagnosis and physical intervention. It is carried out by physical therapists (known as physiotherapists in most countries) and physical therapist assistants (known as physical rehabilitation therapists or physiotherapy assistants in some countries). In addition to clinical practice, other activities encompassed in the physical therapy profession include research, education, consultation, and administration. Definitions and licensing requirements in the United States vary among jurisdictions, as each state has enacted its own physical therapy practice act defining the profession within its jurisdiction, but the American Physical Therapy Association (APTA) has also drafted a model definition in order to limit this variation, and the APTA is also responsible for accrediting physical therapy education curricula throughout the United States of America. In many settings, physical therapy services may be provided alongside, or in conjunction with, other medical or rehabilitation services, including occupational therapy.