Toward Real-Time Detection of Deep Tissue Injury Risk in Wheelchair Users Using Hertz Contact TheoryBy Agam, Limor; Gefen, Amit; Journal of Rehabilitation Research and Development, Vol. 45, No. 4, pp. 537-550
Publication Date: 2008
Study assessed the suitability of a new portable system based on the Hertz contact theory for evaluating internal gluteal muscle stresses under the ischial tuberosities of wheelchair users in real-time as a risk indicator for deep-tissue injury. The Hertz contact theory consists of a series of mathematical equations to calculate normal, hoop, radial, and shear stress components on and within a soft flat surface or half-space when pressed by a rigid hemisphere. Five individuals with paraplegia and a control group of 6 individuals participated in the study. Participants were monitored and processed with the portable system while seated in a wheelchair with an air cell cushion. The resultant internal peak and average stress doses of the control group were compared with those of the paraplegic group and the results were validated against previously-published finite-element (FE) stress data for the same participants. Individuals with paraplegia were characterized by peak muscle-compression stresses that were 2.4-fold higher than those in the control group. A Bland-Altman comparison, a method of data plotting used in analyzing the agreement between two different assays, indicated that stresses recorded by the system used in the study were in satisfactory agreement with the previously-published FE analyses. The study concludes that the new stress-monitoring system has the potential to be a practical means of evaluating internal muscle stresses during everyday life for individuals with paraplegia.
VA Rehabilitation Research & Development Service (Web Site: http://www.rehab.research.va.gov )
Link to text: http://www.rehab.research.va.gov/jour/08/45/4/agam.html
This publication is included in the library of the National Rehabilitation Information Center (NARIC), accession number J55040