First discussed by Nancy Roper, Winifred W. Logan, and Professor Alison Tierney in Britain, this theory revolves around patient care in the sense of maintaining a degree of activity for each patient that is vital to his health. The patient can perform routine duties that she would normally dp by herself at home or elsewhere, and other functions in a routine way. These are referred to as activities of living (AL's). The team devised 12 that can be carried out alone or with the assistance of the nursing staff: safe environment, breathing, communication, being mobile, eating/drinking, elimination of waste, dressing and cleaning oneself, body temperature, working/playing, sleeping, embracing sexuality, and eventually, dying. The nursing staff creates a care of plan specific to the patient using these 12 items as guidelines.
This concept is rooted in reductionism, which states that all illness can be reduced to a biological problem and likens the human body to a machine. The body itself becomes the primary focus of care rather than possible external factors that could have contributed to the patient's illness. Mechanical paradigm shapes how nurses treat patients, or rather, their bodies, as opposed to the whole package of mind, personality, and lifestyle choices. Sharon L. Van Sell, RN and associate professor at Clemson University School of Nursing, argues that this paradigm is shifting and is not generally practiced by nurses in the United States anymore.
Nurses Helen Erickson, Evelyn Tomlin and Mary Ann Swain based it on their collective experience, then collected data to create their new concept in the 1980s. It is broken up into two parts: modeling, where the nurse attempts to model the patient's view of the world and how she should act within it, and role-modeling, based upon the assumption that people want to interact with others. By creating an environment that the patient feels is proper and conducive to his recovery within a hospital setting, nurses then become role models within that paradigm.