What is a Pressure Ulcer?

A pressure ulcer is a localised injury to the skin and/or underlying tissue, usually over a bony prominence caused by pressure or pressure in combination with shear.

They cause pain, discomfort and reduced quality of life to patients and represent a monumental cost to the health and social care system.

The Uncomfortable Truth

Pressure ulcers have a negative impact on quality of life. It is known that individuals with pressure ulcers frequently experience pain combined with fear, isolation and anxiety. Furthermore, Mortality rates are as high as 60% in the elderly with a pressure ulcer within one year of discharge from hospital.


Mortality Rate in Elderly Patients

How Big is the Problem?

Pressure ulcers remain an all too common problem throughout healthcare institutions. The magnitude of the problem is evident in that 18-22% of all patients across acute, long term care and home care environments are said to experience a pressure ulcer.
Given the fact that these injuries may be 95% avoidable, it is clear that attention to pressure ulcer prevention remains vital and often overlooked.

Many people who suffer from long term disabilities, who are elderly or lack mobility often spend long periods of time sitting. When people spend prolonged time sitting they can become very uncomfortable and may develop poor posture, pressure ulcers or both.

Many chairs do not incorporate necessary features for pressure management in seating. These include being able to adjust to a persons individual size, provide postural support, repositioning for weight redistribution and appropriate cushion use.

For example:
In normal upright sitting 75% of body weight supported on 8% body area which leads to high interface pressure.

Normal seated pressure distribution:

Buttocks & Thighs 75%
Feet 19%
Back 4%
Arms 2%

Posture and Pressure Ulcers are Inextricably Linked

When a person sits in an abnormal posture, their weight may not be taken equally through the Ischial Tuberosity’s (IT’s). In a person with a pelvic obliquity for example, a greater percentage of their weight is channelled through the lower IT. This leads to higher interface pressure on this side, therefore increasing the possibility of a pressure ulcer occurring.

Normal Posture

Balanced weight Distribution through ITs

Abnormal Posture

Unbalanced weight Distribution through ITs

95% of Pressure Ulcers are Avoidable
Over-reliance on the Bed and Mattress
Much of the past research and practice has focused on the use of beds and mattresses to treat pressure ulcers, however long and enduring periods of bed rest can have significant cognitive and psycho-social effects. Complications can include depression, learned helplessness and apathy in addition to physical complications such as muscular atrophy, joint contractures, decreased range of movement and pain.

The ability to do even minor tasks like reading, writing, eating and drinking can be affected as well as decreased motivation, which can have an effect on rate of recovery.

Furthermore, the literature does not contain evidence supporting the use of bed rest to facilitate healing of pressure ulcers.

A Better Way

With good sitting posture, a person has a much improved quality of life. Sitting upright may improve a person’s psychological well-being, their ability to interact with others and to do functional tasks. It also facilitates improved physiological functions such as respiration, digestion and elimination when compared to lying in bed. Each of these factors is known to help in the reduction of pressure ulcers.

Therapeutic Clinical Seating for Pressure Management
Martina Tierney and Seating Matters developed a range of therapeutic, clinical seating to reduce the risk and incidence of pressure ulcers.

The design of the seating has been influenced by extensive clinical experience in seating and pressure management. Furthermore extensive testing and clinical trials have been carried out to prove that these results could be replicated in care environments across the world.

How do the Seating Matters chairs reduce pressure ulcers?

The research carried out by the University of Ulster showed there are other elements of pressure management which must be addressed for a more successful outcome. In order to achieve effective pressure management in seating, the Four Principles of Pressure Management should be incorporated.

The Four Principles of Pressure Management in Seating are:

Load the Body

Maximising the surface area contact between the person and the chair and therefore reducing pressure in high risk areas by loading and supporting the persons feet, legs, arms, back and head.

Provide Postural Support

Help keep a person in a mid-line position by supporting their sides, shoulders and head with lateral and head supports. This may ensure equal weight goes through both sides of their body.

Allow Effective Repositioning

The Seating Matters chairs may tilt from 0-45° to allow weight to be redistributed and shifted throughout the day. This is important as it allows for re-oxygenation of the weight bearing tissues.

Use an Appropriate Surface

A proper cushion will facilitate immersion, envelopment and support of the patients anatomical contours. The Seating Matters cushions use a combination of materials to support the principles of immersion and envelopment.

Pressure ulcer classification agreed by the European Pressure Ulcer Advisory Panel (EPUAP)

Category 1

Non-blanchable redness of intact skin Discolouration of the skin, warmth, oedema, induration or hardness may also be used as indicators, particularly on individuals with darker skin.

Category 2

Partial thickness skin loss involving epidermis, dermis or both The ulcer is superficial and presents clinically as an abrasion or blister.



Category 3

Full thickness skin loss involving damage to or necrosis of subcutaneous tissue that may extend down to, but not through underlying fascia.

Category 4

Extensive destruction, tissue necrosis, or damage to muscle, bone, or supporting structures with or without full thickness skin loss.

NB: Category 4 pressure ulcer will always be a Category 4.


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