Influence of angle of back for sitting comfort of wheelchair

Sitting comfort for wheelchairs has been based on the angle of the back-rest. The affect that wheelchair backs had upon the tactile sensation of elderly persons, was based upon wheelchair use via factor analysis. Wheelchair "sitting comfort" was based primarily upon two (2) factors: "Painless at the back" and "Soft at the seat". From a correlation between physical properties (body pressure) and sensory evaluation, it has been discovered that back-rest angle is closely related to how \´painless at the back and soft at the seat a wheelchair is\´.