Terms used in rehabilitation

The alphabetically-order list of words and terms below has links to the term or phrase you choose. Please suggest additions through contacting me here.

Compendium items.

This list, which will expand, gives the areas covered. There is a single word, followed by a brief description. You should click on the word in red to move to it. When you have read an item, you can click on ‘return‘ to come back here.

  • Activities. What are activities in the context of rehabilitation?
  • ADL. Activities of Daily Living. An ambiguous term.
  • Complex. What is complexity?
  • Context. Within rehabilitation, what does it mean?
  • Domain. What is a domain?
  • Domains. What are the domains in the biopsychosocial model of illness?
  • Formulation. What does this term, much used in psychiatry, mean?
  • Impairment. What is an impairment?
  • INTERMED. A measure of complexity
  • Participation. What is (social) participation
  • Specialised. What does this mean as an adjective to ‘rehabilitation;?
  • WHO ICF. World Health Organisation International Classification of Functioning.

What is complexity?

A complex system is one where the output is influence by many factors, each of which has a non-linear inter-relationship with one or more of the other factors and is, at the same time, influenced by one or more of the other factors including, potentially, factors that it is influencing. The key features of a complex system are:

  • multiple factors can influence one factor
  • one factor can influence many others
  • the relationships can be in any direction, or bidirectional
  • the relationships are not linear
  • there are direct and indirect relationships

Complexity needs to be distinguished from being complicated. A system or model may be complicated, because many factors are involved and there are relationships, but if the relationships are all linear, and do not interact, then the outcome of changing one factor is, in principle, predictable.

Thus a complex system is one where the result of changing one factor cannot be predicted. The change might have no effect, or might only change one distant factor, or might change many factors, or even might lead to unstable fluctuations in the whole system. To go back click return.

What is a domain?

A domain originally referred to an area of territory controlled by a single person, but has now extended to mean any collection of items or ideas that collectively form a coherent whole: a well-known example is the web-pages that collectively form a domain, such as http://www.rehabilitationmatters.com.

In the context of the biopsychosocial model of illness, the domains bring together factors that all have one thing in common. The factors may be of different kinds, with a mixture of physical, observable items and conceptual, non-observable items. The domains are also more-or-less complex systems. Systems interact with each other, and there may be higher and lower-order systems; they can be ordered into hierarchies.

Thus a domain refers to a large number of factors that belong within a single system. These systems all themselves are comprised of lower-order systems. For example the body has organs, organs have cells, cells have intra-cellular organelles and so one down to atoms and sub-atomic particles. Similarly the social context has large scales structures such as nations and governments, then local businesses and communities, then personal friends and groups, then family.

Anyone interested in detail about the domains may read on below. Otherwise click here to return to the top.

Domains in biopsychosocial model

Within the biopsychosocial model of illness, the common features that bring many factors together into a single system under one umbrella are as follows:

  • Organs.
    The items all relate to a specific functional part of the body, a part that has a unique function within the body. For example, the skin separates and protects the body from its environment, the endocrine system regulates all body function using hormones, and the central nervous system manages incoming information and controls the body’s response to it. Disturbance is referred to as pathology or disease
  • The body.
    This items all relate to the body as a whole, the collection of organs working together as a single system which has, as systems theory predicts, properties and functions that emerge unrelated to the function of individual organs. Disturbance is referred to as impairment.
  • Behaviour.
    This system relates to the person, as an emergent function of the body, interacting with the physical environment, including people as objects. It is actions which taken together are working towards some goal which may be immediate, such as drinking water to satisfy thirst, or very long-term, such as studying to obtain a PhD or become a senior academic. Disturbance is referred to as disability, or a limitation on activities.
  • Social participation.
    This system relates to the person interacting with his or her social environment, other people. It concerns performing social roles, developing social relationships, and forming social networks. It is entirely conceptual. Disturbance was originally referred to as handicap but is now referred to as a limitation on social participation. There is debate about terminology and precise definition.
  • Physical context.
    This concerns the person’s (body’s) physical environment, both immediate and more generally. It refers to everything that can be seen or felt, including weather, buildings, and any technology, and it can include people in their role of providing physical care.
  • Social context.
    The relates to the social environment, both immediate and more generally. It refers to all items contributing to role performance – social networks and opportunities, attitudes of others, laws and culture etc.
  • Personal context.
    This is a more complex construct, and it concerns “what the patient brings to the situation”. It covers matters such as accumulated experiences, attitudes, beliefs, life priorities, aspirations etc.
  • Temporal context – life.
    This refers to the person’s stage in life, anywhere from ‘just born’ to ‘end-of-life’. Its importance arises from all the factors associated with age and stage of life (more the stage than the age). For example someone of 18 years is probably still dependent on parents, likely to be in education of just left, with many expectations of the future but little reserve or experience.
  • Temporal context – illness.
    This refer to the person’s stage in their illness – very recent onset, had it a while, lived with it since a baby etc. This will impact upon prognosis, expectation, and personal strengths and weaknesses.
  • Judgement.
    Two factors lie outside the model, and they reflect the independent judgements made by the patient. One is choice. This is the fact that, somehow or other, a patient makes choices between possible courses of action. The other is well-being. Only the patient can say what their quality of life, their state of well-being is.

These domains are explored in more detail in different parts of the site. Click here to return.


An impairment, according to the Oxford English Dictionary is the “state of being impaired”, and impaired is being “weakened or damaged”. The term has come to incorporate rather more meaning in the word, impairment, than the dictionary suggests. Unfortunately there is little discussion of the quite wide range of ideas now associated with impairment. This will outline the range.

The starting point is that impairment, in rehabilitation and within the biopsychosocial model of illness, refers to ‘weakness or damage’ to the body. It is best conceived of as ‘an alteration in the structure and/or functioning of a person’s body’, to distinguish it from changes in the organs that, taken together, comprise the body.

At this point it is important to note that it is unwise, if not impossible, to use the adjectives ‘normal’ and ‘abnormal’. There are no good definitions, and there are many interpretations. So we will refer to change as perceived by the person, or alteration as perceived by an observer.

There are three different uses of the term impairment within rehabilitation are given below.

The most obvious group are structural impairments. These are visible or palpable. They include missing body parts such as an amputated foot, altered body parts such as facial scarring, and structural limitations upon movement in body parts such as contractures. These, in the medical world, are signs.

The next group of impairments are constructs generated and used by clinicians to explain observed behaviours. They are not, in themselves, visible. Examples abound in neurology: aphasia (impairment in the use of language) for people who have difficulties in communication involving language; spasticity for people who have increased tone, spasms, slow and clumsy movements etc. These impairments are based on assumptions about physiology and anatomy, and simply specific areas of damage within the body.

The third group are experiences reported by the patient, with pain and other sensory changes being the most obvious, but a whole range of other cognitive and emotional phenomena are included – fatigue, forgetfulness, slowness in thinking, feels low or angry. Some of these will be used as evidence to support a particular construct such as ‘post-concussion syndrome’.

The important point to note is that, generally speaking, structural impairments are directly observable and can be verified. In contrast the constructs and experiences are entirely derived from patient behaviour, including self-report. The existence of the phenomenon as an impairment depends entirely on the interpretations and judgements of the clinician. Differences of opinion are not uncommon.

Further discussion can be found elsewhere on the site. Click here to return to the top.


Specialised does not have any meaning unique to rehabilitation, but is a word often used to describe some aspect of rehabilitation, usually a service. When placed before the word, rehabilitation, it has one of three meanings:

  1. a service delivering holistic rehabilitation, as contrasted to a service which uses the word but has a limited capacity, without a full multi-disciplinary team able to assess and treat the full range of their patients’ problems;
  2. a service which has particular expertise within the whole field of rehabilitation, when it should be expressed as “This service is specialised in neurological rehabilitation”, specifying the specialisation after the rehabilitation;
  3. a service which provides a “low-volume, high-cost” service and hence, within the context of the UK National Health Service is deemed (at present, 2021) to be specialist. It is an abuse of the word, to satisfy a bureaucracy.

None of these three meanings is correctly given by using the word, specialist as an adjective for the noun, rehabilitation. Taking them in order, they would be better described using the word(s):

  1. complete, or comprehensive, to distinguish the service from those offering an incomplete service with a minimal team;
  2. no preceding adjective should be used, and the description of expertise within the service should follow as a qualifying or additional phrase;
  3. high-cost, low-volume, specifying precisely what type of rehabilitation service it is.

For a much more detailed discussion, read this blog. Click here to return to the top.


Within rehabilitation jargon an activity refers to any goal-directed set of tasks or actions that a person does. If performance of an activity is limited or absent, then an alternative word is disability. Activities are functional, in the sense that they have a purpose and try to achieve something. Yet another way to consider them is as a behaviour. Examples of activities include walking, driving, contributing to a committee, and reading.

An activity may also carry social meaning. For example, if contributing to a discussion in a committee, a person is also indicating their role as ‘a committee member’ (or ‘secretary to the committee’). Many activities are associated with social meaning, but the meaning depends crucially on the context. Someone running in a street could be there as a criminal running from a crime, someone running to catch a bus, an athlete training for a marathon or a mother chasing her child who is about to cross a busy road.

Click to return.

What is participation?

Participation is one of the more confusing words used in rehabilitation jargon, for several reasons.

Its plain, English meaning refers to participating in an activity, and within rehabilitation this is of considerable important. The word, participation may be used in this context, quite correctly. To distinguish it, if needed, it is probably clearer to use the word, engagement as this has no alternative meaning.

Participation, within the jargon, is usually preceded by social so the the phrase is social participation, a term used within the World Health Organisation’s International Classification of Functioning. Even there it meaning is not well defined – see here for a discussion. It relates to a person’s involvement in activities that carry social meaning – but almost all activities do.

As a term, it is better avoided. If used, the user should expand on the intended meaning. If heard or read, the listener or reader needs to establish or investigate what meaning it carries.

Concepts surrounding the term include:

  • social networks, the people that the person has some form of relationship with;
  • social interaction, which extends beyond networks to people met incidentally;
  • roles and role function, realising that roles cannot be externally evaluated but are attributed by the actor and the observer or other actor(s);
  • satisfaction with social interactions;
  • number of people seen over a set time, and loneliness.

There are probably other related concepts. Click to return.

Formulation (of a case)

Formulation is a term used mostly in psychiatry where it is now also closely linked to the use of the biopsychosocial model of illness. A useful resource can be found here.

Formulation is the end-product of assessment. It is a synthesis of all available information that summarises the present situation, its development, causes and exacerbating factors, its prognosis and potential management. It is the foundation upon which all action is based. It needs to be relatively concise, but at the same time to encompass all important information from all relevant domains of the biopsychosocial model.

It is described in more detail elsewhere in the website. Click to return.


Context refers to all the factors that are not specifically part of the current clinical state of the patient. It includes their environment in its broadest sense, not just physical, but it also includes their personal history and personal attitudes and expectations. Context is very personal – it is the specific house, the particular people who are family, or work colleagues, the good or bad experience of a particular hospital, etc. Without context, a description is almost without value.

Within rehabilitation the main contextual domains are: physical, the observable environment outside the person’s body; social, the culture, the laws, the social care system etc; the personal context, a mixture of beliefs, attitudes, aspirations etc that give the person a personality; temporal context within the illness, and temporal context within the person’s life, sometimes summarised are their ‘narrative’.

Click to return.

ADL: Activities of Daily Living

The abbreviation, ADL is widely used. It stands for Activities of Daily Living, a phrase that is also widely used. Unfortunately, it has no precise meaning over and above the word activities (see above). The commonest meaning for ADL is personal activities of daily living which usually encompasses things that allow you to be independent, not needing daily help or support, They include: continence and toileting; grooming and bathing or showering; dressing; walking and getting about the house; and feeding (but not cooking). Everything else may be referred to as extended activities of daily living, but other groups exist: domestic ADL, community ADL, leisure activities etc. So if anyone say ‘ADL” or ‘Activities of Daily Living’, ask what they mean, and what they include within the term.

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The World Health Organisation recognised the power of the biopsychosocial model of illness immediately it was published in 1977, and by 1980 it had published its first classification of the consequences of disease (to complement the International Classification of Diseases ICD). The document was the International Classification of Impairments, Disabilities and Handicaps (WHO ICIDH). This was not entirely satisfactory, and in 2000 the International Classification of Functioning, Disability and Health (WHO ICF) was published. (here) The actual classification is only available of the web. In my view it is unusable as a classification, but the concepts are important. However, there are many people who think it useful, and ‘core data sets’ are being developed for many common diseases. (here)

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The INTERMED (that is its name I think, not an abbreviation) is a measure of complexity developed using the biopsychosocial model of illness. It was developed in 1995, before the model was expanded in the WHO ICF classification. It is a good screening tool for detecting people with complex health problems. (here) Various forms exist.

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