Determination of the Coefficients of Friction Between Pant Fabrics and Seat Covers

Abstract

Background

Shear forces related to friction are one of the risk factors shown to increase the likelihood of wheelchair users developing pressure injuries (PIs), especially in the buttocks region. Thus, reducing the coefficient of friction between the seat and the person’s pants could be a means toward reducing the incidence of PIs.

Objective

This study aimed to: (1) determine the coefficients of friction of seven commonly worn pant fabrics and two seat cover fabrics and (2) investigate the effects of a deformable seat cushion on the measurement of the coefficients of friction.

Methods

A mechanical system (termed sled) had a pants fabric secured to its bottom and was placed on top of a custom seat pan with seat cover. The seat pan was tilted from horizontal until the sled system started to slide on the seat pan. The coefficient of friction between the two fabrics was calculated using kinematics data obtained from a motion capture system.

Results

The office fabric seat cover produced smaller coefficient of friction than the vinyl seat cover for all of the pant fabrics. Women’s khakis demonstrated one of the smallest coefficients of friction, and denim demonstrated one of the largest coefficients of friction consistently across both seats covers.

Conclusion

Replacing traditional vinyl seat covers in wheelchairs with a fabric closer to an office seat fabric is one approach to reducing frictional forces at the seat interface. Although optimal pant fabrics can be identified for shear force reduction, the results also depend on the seat cover fabric.