Shear stress measured on beds and wheelchairs.
Local shear is understood to be one of the principal risk factors for the development of pressure sores. There is a need for a small deformable sensor that can measure the shear force between skin and deformable materials without disturbing the shear phenomenon. In the present study a new shear sensor is introduced with a contact area of 4.05 cm2. A series of validation experiments was performed with ten healthy young subjects. It was demonstrated that with a forward-tilted seat, the sum of the local shear forces between skin and sensormat is equal to the resultant shear force measured with a force plate. This result serves as a validation of the new sensor. The shear values recorded are 4.8 kPa in the longitudinal direction and 8.5 kPa in the transversal direction while sitting in a wheelchair, and 5.6 kPa in the longitudinal direction and 3.1 kPa in the transversal direction on a mattress of a hospital bed, while in sitting position in bed.
Goossens
R H
RH
Erasmus University Rotterdam, Faculty of Medicine, Department of Biomedical Physics and Technology, The Netherlands.
Snijders
C J
CJ
Holscher
T G
TG
Heerens
W C
WC
Holman
A E
AE
D001513:Beds; D001696:Biomechanical Phenomena; D006801:Humans; D011187:Posture; D015203:Reproducibility of Results; D013314:Stress, Mechanical; D014910:Wheelchairs