Assessing Plus Sized People: Anthropometrics and Activity Analysis.

This article looks to explore the meaning of anthropometrics in practice and how to account for the diversity in human measurements when supporting engagement in occupation and promotion of function.

Anthropometrics is the study of human measurements and movement and is derived from the Greek ‘anthropos’ meaning human and ‘metron’ meaning measure. It is not often discussed in occupational therapy literature; however, it is an important part of decision making around adaptations and the environment.

Anthropometrics is often used in building design and guides things like dimensions, door widths and type and position of door handles to enable people to use the environment with ease (Designing Buildings, 2022). Anthropometrics is also used to consider whether the size and shape of personal protective equipment is appropriate (HSE, 2005), the planning of workstations to be used in seating and standing (Skilling, 2016) and sizing clothing (Daannen & Reffletrath, 2007). The study of human sizes is important across all areas of life.

Part M of the Building Regulations (access to and use of buildings) and the equivalent in Scotland, Wales, and Northern Ireland, provides a guide to minimum compliance with the regulations. When considering plus sized people in their home environment, it is likely that the minimal guidance set out in the building regulations would not be sufficient to meet an individuals’ needs and how they move and carry out bathroom occupations. It is important to understand how someone moves, the influence of a walking aid, the presence of another person in the bathroom, a person’s turning circle, their ability to reach and bend and where items are placed to reduce the risk of falls.

Occupational therapists are expert in occupation, the things people need, want, or are expected to do as individuals within families or communities that bring meaning and purpose to life (WFOT, 2022). When working with plus sized clients, to support them to maximise their occupational performance and maintain their life roles, anthropometrics is essential when making appropriate recommendations. This does not mean that we should always take measurements of different parts of a persons’ body; moreover, it is important to understand where someone carries their weight and the effect of this on function.

This is where activity analysis is key.

Activity analysis is the process of breaking down an activity into steps and examining its components. Activities, such as using a toilet, can be separated into constituent elements to analyse the skills required, understand a person’s ability to undertake an activity, or identify areas where the activity can be adapted to improve occupational performance (Creek, 2008). When a plus sized person struggles with toileting it is important to analyse how they are carrying out their bathroom occupations to fully understand why their occupational performance is affected and how anthropometry is impacting this.

Occupational therapists are skilled in assisting people with toilet transfers and often this is the focus of an assessment when reviewing toileting. However, there is so much more to the occupation of toileting than sitting and standing on and off the toilet.

An activity analysis of toileting has been produced by Closomat and can be found here:

An occupational therapist, skilled in activity analysis, appreciates the complexity of an activity and the physical, cognitive and intrapersonal demands required to carry it out effectively.

A plus sized person may struggle to wipe after using a toilet as they cannot lean to one side of the toilet, as leaning out of their base of support puts them at risk, or due to a large gluteal shelf they cannot reach to the rear, or a large panniculus means wiping from the front is impossible. They may struggle to reach the toilet roll as they have reduced range of movement in the upper limbs to lack the multi-limb coordination required to do this.
The environment may also not support optimal occupational performance. For example, the toilet may be located too close to a wall, forcing a plus sized person to be unable to sit centrally on the seat and increasing the risk of falls and waste not falling into the pan. Similarly, the proximity of the wash hand basin may cause similar issues, reducing space to sit and move the upper limbs to reach to wipe.

If it can be argued that activity analysis is essential in optimising occupational performance in the bathroom, where does anthropometrics fit in? A person’s BMI may be known prior to an initial assessment and conclusions as to the presentation of a person may be made prior to a face to face meeting. However, BMI is calculated by squaring the height. This reduces the impact of leg length and presumes body mass distribution at each level of height (Nutall, 2015). A BMI does not account for anthropometrics.

Occupational therapy recommendations should always account for a person’s anthropometrics and the effect of intervention on this. When adapting the home environment, it is important to understand how a person interacts with their environment and how the environment can be changed to make it ergonomically effective. A person who carries most of their weight to the front around their abdomen, may have to adopt a particular posture (for example, with their legs open to accommodate their size). A person who carries their weight around the hips may find the width of a standard toilet seat uncomfortable and provides ineffective support. When assessing someone for the first time, it is essential to review a person’s anthropometry and evaluate how this may affect function.

As part of a holistic assessment of a person, an occupational therapist should critically think about the occupations that may be affected by a person’s weight and body fat distribution and ensure this is factored into a robust clinical assessment. Due to the sensitive nature of the discussion of toileting across cultures, it is helpful if an occupational therapist is aware of the impact on being plus sized on bathroom occupations and address sensitive issues with skill and patience as part of a dynamic and holistic assessment.

• Creek, J. & Bullock, A. (2008). Planning and Intervention. In Creek, J. & Lougher, L. (4th Edition). Occupational Therapy and Mental Health. Edinburgh: Churchill Livingstone.
• Daannen HAM & Reffletrath, PA (2007) Sizing in Clothing. https://www.sciencedirect.com/science/chapter/edited-volume/abs/pii/B9781845690342500067?via%3Dihub
• HSE (2005) Revision of body size criteria in standards- protecting people who work at height. https://www.hse.gov.uk/index.htm
• Nuttall, FQ (2015) Body Mass Index. Obesity, BMI and health: A critical review. Nutrition Today: May/June 2015 – Volume 50 – Issue 3 – p 117-128
• Skilling, EJ (2016) human factors in the chemical under process industries: making it work in practice. https://www.sciencedirect.com/book/edited-volume/9780128038062/human-factors-in-the-chemical-and-process-industries?via=ihub%3D
• WFOT (2022) About occupational therapy Retrieved from: https://wfot.org/about/about-occupational-therapy Accessed on 25.03.2022