Clinical reasoning 101

Clinical reasoning, the HOAC II and the ICF — what are they?
Get the basics of the concepts from this very brief ‘Reasoning 101’ module.

Clinical reasoning

Clinical reasoning is “the sum of the thinking and decision-making processes associated with clinical practice” (Edwards et al. 2004, Higgs et al. 2011). During this process, the therapist analyses multiple variables contributing to the patient’s limited physical capacity (the ability to execute a task or action in a standard environment) and performance (what the patient can do in his or her own current environment). The key elements of the process include generation of hypotheses of factors assumed to underlie the limitations of physical capacity and performance and postulation of the magnitude of those factors. The therapist interacts with the patient and other persons involved in the patient care (family, other health care professionals) and guides the patient in finding meaningful goals and health management strategies (Edwards et al. 2004). All decisions and actions need to be made in line with professional ethics and community expectations (Higgs et al. 2011).


Jules Rothstein and John Echternach first published the Hypothesis Orientated Algorithm for Clinicians (HOAC) – a method for evaluation and treatment planning in 1986 (Rothstein et al. 1986, Echternach et al. 1989). In 2003 the algorithm was updated to be compatible with the contemporary physical therapy practice. The update was termed the Hypothesis Orientated Algorithm for Clinicians II (HOAC II) (Rothstein et al. 2003, Riddle et al. 2003). The HOAC II offers a conceptual, patient-centred framework for physical therapists to use in the management of any type of patient (Riddle et al. 2003). It addresses the five elements of patient management: examination, evaluation, diagnosis, prognosis and intervention as advocated by the American Physical Therapy Association (APTA) (APTA 2003, Rothstein et al. 2003). Important for contemporary physical therapy, the HOAC II provides a means to engage in evidence-based practice and to differentiate between the types of evidence and science used (Rothstein et al. 2003, Thoomes et al. 2011).

The ICF & the ICF Core Sets

In their HOAC II guide to patient management Rothstein et al. (2003) adopted the terminology of the Nagi model (Nagi 1964). However, on the terminology of the International Classification of Functioning, Disability and Health (ICF) (WHO 2001) is integrated in the HOAC II clinical reasoning framework. This choice reflects the view of the World Confederation of Physical Therapy (WCPT) that adopted a motion supporting the implementation of the ICF in physical therapy in 2003 (Escorpizo et al. 2010). The ICF Core Sets were developed as a practical tool to facilitate the systematic and comprehensive description of functioning in clinical practice (Kesselring et al. 2008, Rauch et al. 2008) and therefore integrated in the case studies.


  • American Physical Therapy Association (APTA). Interactive Guide to Physical Therapist Practice. Alexandria: American Physical Therapy Association; 2003.
  • Echternach JL, Rothstein JM: Hypothesis-oriented algorithms. Phys Ther. 1989;69:559-64.
  • Edwards I, Jones M, Carr J, Braunack-Mayer A, Jensen G. Clinical reasoning strategies in physical therapy. Phys Ther. 2004;84:312-35.
  • Higgs J, Jones M. Clinical decision making and multiple problem spaces. In: Higgs J, Jones MA, Loftus S, Christensen N. Clinical reasoning in health professions. Amsterdam: Elsevier;2008. p. 4-19.
  • Escorpizo R, Stucki G, Cieza A, Davis K, Stumbo T, Riddle DL. Creating an interface between the International Classification of Functioning, Disability and Health and physical therapist practice. Phys Ther. 2010;90:1053-63.
  • Kesselring J, Coenen M, Cieza A, Thompson A, Kostanjsek N, Stucki G. Developing the ICF Core Sets for multiple sclerosis to specify functioning. Mult Scler. 2008;14:252-4.
  • Nagi SZ. A study in the evaluation of disability and rehabilitation potential: concepts, methods, and procedures. Am J Public Health Nations Health. 1964;54:1568-79.
  • Rauch A, Cieza A, Stucki G. How to apply the International Classification of Functioning, Disability and Health (ICF) for rehabilitation management in clinical practice. Eur J Phys Rehabil. 2008;44(3):329-42.
  • Riddle DL, Rothstein JM, Echternach JL. Application of the HOAC II: an episode of care for a patient with low back pain. Phys Ther. 2003;83:471-85.
  • Rothstein JM, Echternach JL. Hypothesis-Oriented Algorithm for Clinicians: a method for evaluation and treatment planning. 1986;66(9):1388-94.
  • Rothstein JM, Echternach JL, Riddle DL. The Hypothesis-Oriented Algorithm for Clinicians II (HOAC II): a guide for patient management. Phys Ther. 2003;83(5):455-70.
  • Thoomes EJ, Schmitt MS. Practical use of the HOAC II for clinical decision making and subsequent therapeutic interventions in an elite athlete with low back pain. J Orthop Sports Phys Ther. 2011;41(2):108-17.
  • World Health Organization. International Classification of Functioning, Disability and Health: ICF. Geneva: World Health Organization; 2001.