Support surface is a medical term used to describe materials such as mattress

Mattress

A mattress is a manufactured product to sleep or lie on, consisting of resilient materials and covered with an outer fabric or ticking. In the developed world it is typically part of a bed set and is placed upon a foundation....

es that support people who are bed-ridden through illness. Research and development of appropriate support surfaces can alleviate some of the complications of immobility, such as bedsore

Bedsore

Bedsores, more properly known as pressure ulcers or decubitus ulcers, are lesions caused by many factors—such as unrelieved pressure, friction, humidity, shearing forces, temperature, age, continence, and medication—to any part of the body, especially portions over bony or cartilaginous areas such...

s and respiratory

Respiration (physiology)

'In physiology, respiration is defined as the transport of oxygen from the outside air to the cells within tissues, and the transport of carbon dioxide in the opposite direction...

 problems.

The National Pressure Ulcer Advisory Panel's (NPUAP) Support Surface
Standards Initiative (S3I) has released the first version
of its Terms and Definitions Document. This set of definitions is
provided in an attempt to redefine commonly used and confused terms.
The terms describe support surface features, components, categories,
and performance characteristics.

The Terms and Definitions Document and an evaluation form can be found
at NPUAP`s site

Problems of immobility

As long as people have been bed-ridden through illness, they have fallen victim to the complications of immobility. These can include, but are not limited to:

• Disorders of the skin
  Dermatology
  Dermatology is the branch of medicine dealing with the skin and its diseases, a unique specialty with both medical and surgical aspects. A dermatologist takes care of diseases, in the widest sense, and some cosmetic problems of the skin, scalp, hair, and nails....
  
   and underlying tissue.
• Pneumonia
  Pneumonia
  Pneumonia is an inflammatory condition of the lung—especially affecting the microscopic air sacs —associated with fever, chest symptoms, and a lack of air space on a chest X-ray. Pneumonia is typically caused by an infection but there are a number of other causes...
  
   and other related respiratory illnesses.
• Disorders of the renal
  Urology
  Urology is the medical and surgical specialty that focuses on the urinary tracts of males and females, and on the reproductive system of males. Medical professionals specializing in the field of urology are called urologists and are trained to diagnose, treat, and manage patients with urological...
  
   and gastrointestinal systems
  Gastrointestinal tract
  The human gastrointestinal tract refers to the stomach and intestine, and sometimes to all the structures from the mouth to the anus. ....
  
  .
• Disruption in the cognitive systems resulting in neuro-psychological disorders
  Psychopathology
  Psychopathology is the study of mental illness, mental distress, and abnormal/maladaptive behavior. The term is most commonly used within psychiatry where pathology refers to disease processes...
  
  .

Critically ill patients, unable to move spontaneously, are nursed in the supine

Supine

In grammar a supine is a form of verbal noun used in some languages.-In Latin:In Latin there are two supines, I and II . They are originally the accusative and dative or ablative forms of a verbal noun in the fourth declension, respectively. The first supine ends in -um. It has two uses. The first...

 position for extended periods of time. This is in striking contrast to normal human beings who, even during sleep

Sleep

Sleep is a naturally recurring state characterized by reduced or absent consciousness, relatively suspended sensory activity, and inactivity of nearly all voluntary muscles. It is distinguished from quiet wakefulness by a decreased ability to react to stimuli, and is more easily reversible than...

, change their position approximately every 11.6 min–a phenomenon described by Keane as "minimum physiological mobility requirement." The deleterious effects of prolonged immobilization affect the heart

Heart

The heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...

, vascular system, musculoskeletal system

Musculoskeletal system

A musculoskeletal system is an organ system that gives animals the ability to move using the muscular and skeletal systems...

, skin, and kidneys, despite the usual nursing practice of repositioning every two hours.

Traditional methods of dealing with immobility

The traditional method of dealing with immobility is to turn the patient at least every two hours, following a side-back-side protocol. Through the years, many mechanical systems have been improvised to prevent these complications of immobility:

• Sheepskin
  Sheepskin
  Sheepskin is the hide of a sheep, sometimes also called lambskin or lambswool.Sheepskin may also refer to:* Parchment, a thin material made from calfskin, sheepskin or goatskin** Diploma, originally made of sheepskin...
  
   laid on top of the patient's mattress.
• Foam mattresses and overlays.
• Non-powered and powered air mattress
  Air mattress
  An air mattress is an inflatable mattress/sleeping pad. Due to its buoyancy, it is also often used as a water toy/flotation device, and in UK is termed as a lilo .-For sleeping:...
  
  es