Education in Motion / EIM Blog / September 2019 / Standardized Terms in Seating and Mobility

Standardized Terms in Seating and Mobility

Are we all speaking the same language in seating and mobility? Have you heard a wheelchair cushion being called a "pillow" by someone who does not work in this field? Do you call a "wheel lock" a "brake" on a wheelchair or an arm support an "armrest"? Is a pelvic positioning belt the same as a pelvic belt for transportation of occupied wheelchairs? (The answer to this last question is no!) The language of seating and mobility is evolving and, in fact, becoming standardized. Let's take a look at why standardization in terms is important and review a sampling of common terms.

Why Standardization in Terminology Is Important

When we went to university to become therapists, many of us learned a new language. We learned the language of medical terms and their associated definitions. This helps us to have a common language when we speak with other allied health and medical professionals. Since we use the same terminology, we understand one another, making communication easy, clear, and efficient. We know that we cannot use medical jargon when speaking with clients, so we use layman's terms, or other words that ensure clear communication with clients. The choice of words matters when we communicate.

Standardization in terms used in seating and mobility matters just as much as those used in medical language. There is a material difference between a pelvic positioning belt and a pelvic belt for transportation, so it is important that standards exist. The standards provide definitions of terms so that all who are involved in seating and mobility are speaking a common language - the language of assistive technology. This allows us to ask for one thing and be certain that whomever we are speaking with will understand our communication and we will receive what we have requested.

A group in the United States, led by Kelly Waugh, PT, MAPT, ATP worked together to draw upon several recognized industry resources to develop a comprehensive Glossary of Wheelchair Terms and Definitions. Over 500 terms are listed in various categories, including wheelchairs & their components, seating, and seated posture. The final sentence of the preface to this guide sums up the relevance of standardized terms very well. It states:

Achieving the goal of a common vocabulary will ultimately help therapists, suppliers and other stakeholders involved in wheelchair prescription improve the quality and efficiency of their service delivery, with improved outcomes for consumers.

It is a win-win-win situation when standardized terms in seating and mobility are used.

Updated Terms and Definitions

Let's consider terms that relate to seating support. Terms that are deprecated will be reviewed and the preferred terms and their meanings will be highlighted.

Throughout the Glossary of Wheelchair Terms and Definitions, the word "rest" has been replaced with "support." For example, the terms "footplate," "footrest," and "foot box," have been replaced by "foot support." Its definition is "Postural support device intended to contact the inferior surface of the foot to provide support to the foot and lower leg." (p. 56). The preferred term for an "armrest" is an "arm support." Its definition is "Postural support device intended to contact the inferior surface of the forearm to provide support to the upper extremity." (p. 56). Similarly, the preferred term for a "headrest" is a "head support" and its definition is "Postural support device intended to contact the posterior surface of the head to provide support to the head." (p. 56). A final example is "back support." This term replaces "back," "backrest," and "seat back." The definition for a back support is "Postural support device intended to contact the posterior surface of the sacral, lumbar and/or thoracic segments of the trunk to provide support to the torso." (p. 55). If we think a little more about the language used, the term "support" conveys an active image and a required element for posture and positioning; whereas the language of "rest" is passive and may not fully convey a component's importance in positioning.

Let's think about some positioning components. The preferred term for a "pommel," "abductor," or "abductor wedge" is a "medial knee support block." This term means "Postural support device intended to contact the medial surface of both the right and left knees." (p. 59). A "medial thigh support," previously known as either a "leg abductor support" or a "leg dividing support" is a "Postural support device intended to contact the medial surface of the thigh." (p. 59). Examples of medial thigh supports are medial thigh straps and the medial thigh support surfaces in contoured seat cushions.

Similarly, we find an update of terms related to lateral support. What was once called a "hip guide," "hip block," or "lateral hip support" has been standardized to "lateral pelvic support." The definition for this term is "Postural support device intended to contact the lateral side of the pelvic segment, defined as the region from the posterior buttocks to slightly distal to the greater trochanter." (p. 60). The term "lateral thigh support" replaces "adductor," "adductor pad," "leg strap," "thigh block," etc. The definition of a lateral thigh support is "Postural support device intended to contact the lateral side of the thigh in the region from just in front of the greater trochanter to jus tin front of the femoral condyle." (p. 60). The term "lateral knee support" also replaces the terms "adductor," "adductor pad," and "adductor strap." A lateral knee support is "Postural support device intended to contact the lateral surface of the knee, in the area of the lateral femoral condyle." (p. 60). The terms "lateral knee support" and "lateral thigh support" help to clarify support position relative to the body in a way that the word "adductor" is unable to do.

A final example is the updated term of "solid seat insert," which replaces the terms "solid insert," "rigid seat insert," "rigidizer," and "sag compensator." The definition of a solid seat insert is "Additional, removable support structure inserted below the seat cushion, either inside or outside the cushion cover, which is used without removing the integrated wheelchair seat sling." (p. 54).

Current Practice

The terms mentioned above are only a small sample of the terms and definitions outlined in the Glossary of Wheelchair Terms and Definitions. There are many additional terms related to wheelchairs and their components, seating, body segment angles, seating support surface angles, and linear dimensions listed in the glossary. Have all of the terms listed in the glossary become the common language of assistive technology professionals and manufacturers? The answer is no. If we think of this through the lens of knowledge translation, we can understand that awareness must precede action. Many people are not aware of the work that has been done to develop standardized terms. Once people have become aware, it can take some time before the new language and terms are fully incorporated into daily practice. Since the seating and mobility field has so many different groups involved, from health care professionals to vendors and manufacturers, it may take some time before the terms become fully realized, but awareness is the first step.

Sheilagh Sherman, BA, BHScOT, MHM, OT Reg. (Ont.)

Sheilagh Sherman, BA, BHScOT, MHM, OT Reg. (Ont.) joined Sunrise Medical Canada in 2010 as our full-time Clinical Educator. Prior to joining Sunrise, Sheilagh gained extensive clinical experience from working in a variety of settings, including in-patient rehabilitation, complex continuing care, and community rehabilitation. As Clinical Educator, Sheilagh is a clinical resource for therapists across Canada involved in seating and mobility. She teaches in-services and leads workshops & seminars on the clinical aspects of seating and mobility. In addition, Sheilagh hosts monthly webinars for therapists and vendors.


  1. Waugh, K. and Crane, B. (2013). Glossary of wheelchair terms and definitions. Denver, CO. University of Colorado Denver. Available from:

Published: 2019-09-30

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