A Comparison of the Average Sitting Pressures and Symmetry Indexes between Air-adjustable and Foam Cushions

[Purpose] The purpose of this study was to determine the best adjustable cushions, for the maintenance of normal sitting balance by healthy persons in wheelchairs, from a foam cushion, and a newly-developed air-adjustable cushion. [Subjects] Eighteen healthy participants (9 men, 9 women) were recruited. [Methods] Participants were evaluated using the Force Sensing Array System to assess average sitting pressure and the symmetry index of chair sitting under the following conditions: no seat cushion, a foam cushion, and a newly-developed air-adjustable cushion. [Results] The results show that there were no significant differences among the average sitting pressures which were measured on the hard surface of a chair, a foam cushion, and the newly-developed cushion. The air-adjustable cushion's symmetry index turned out to be closer to 0 than those of the foam cushion and the hard surface of the chair. [Conclusion] We suggest that the newly-developed air-adjustable cushion contributes to a more symmetrical sitting posture than the basic foam cushion or no seat cushion.