Convoluted foam cushion
Segmented foam cushion
Low profile segmented air cushion
High profile segmented air cushion
Foam and viscoelastic foam cushion
Foam and viscous fluid cushion
Honeycomb cushion
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Polyurethane refers to a class of polymers composed of organic units joined by carbamate (urethane) links. In contrast to other common polymers such as polyethylene and polystyrene, polyurethane is produced from a wide range of starting materials. This chemical variety produces polyurethanes with different chemical structures leading to many different applications. These include rigid and flexible foams, and coatings, adhesives, electrical potting compounds, and fibers such as spandex and polyurethane laminate (PUL). Foams are the largest application accounting for 67% of all polyurethane produced in 2016.
An ulcer is a sore on the skin or a mucous membrane, accompanied by the disintegration of tissue. Ulcers can result in complete loss of the epidermis and often portions of the dermis and even subcutaneous fat. Ulcers are most common on the skin of the lower extremities and in the gastrointestinal tract. An ulcer that appears on the skin is often visible as an inflamed tissue with an area of reddened skin. A skin ulcer is often visible in the event of exposure to heat or cold, irritation, or a problem with blood circulation.
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Gait deviations are nominally referred to as any variation of standard human gait, typically manifesting as a coping mechanism in response to an anatomical impairment. Lower-limb amputees are unable to maintain the characteristic walking patterns of an able-bodied individual due to the removal of some portion of the impaired leg. Without the anatomical structure and neuromechanical control of the removed leg segment, amputees must use alternative compensatory strategies to walk efficiently. Prosthetic limbs provide support to the user and more advanced models attempt to mimic the function of the missing anatomy, including biomechanically controlled ankle and knee joints. However, amputees still display quantifiable differences in many measures of ambulation when compared to able-bodied individuals. Several common observations are whole-body movements, slower and wider steps, shorter strides, and increased sway.
References
- 1 2 Ferrarin, M; Andreoni, G; Pedotti, A (2000). "Comparative biomechanical evaluation of different wheelchair seat cushions". Journal of Rehabilitation Research and Development. 37 (3): 315–24. PMID 10917263.
- ↑ Kosiak, M (1961). "Etiology of decubitus ulcers". Arch Phys Med Rehabil: 19–29. PMID 13753341.
- ↑ Stewart, SFC; Palmieri, V; Cochran, GVB (1980). "Wheel chair cushion effect on skin temperature, heat flux, and relative humidity". Arch Phys Med Rehabil. 61 (5): 229–33. PMID 7377945.
- ↑ Finestone, HM; Levine, SP; Carlson, GA; Chizinsky, KA; Kett, RL (1991). "Erythema and skin temperature following continuous sitting in spinal cord injured individuals". J Rehabil Res Dev. 28 (4): 27–32. doi: 10.1682/JRRD.1991.10.0027 . PMID 1941646.
- ↑ Bennet, L; Kavner, D; Lee, BK; Trainor, FA (1979). "Shear vs . pressure as causitive factors in skin blood occlusion". Arch Phys Med Rehabil. 60: 309–14.
- 1 2 3 Sprigle, Stephen; Press, Larry; Davis, Kim (2001). "Development of uniform terminology and procedures to describe wheelchair cushion characteristics". J Rehabil Res Dev. 38 (4): 449–61. PMID 11563498.
- ↑ Fleming, Joe. "Wheelchair Cushion: Selection and Maintenance". Vive Health. Retrieved 6 January 2017.