Planar seat is indicated when there is no seated deformity. Which option is the correct description?

• A. Bevel front edge of seat
• B. Planar seat
• C. Sling seat
• D. Curved seat

Answer: (B)

A seating surface that is flat and uncontoured is used when there is no seated deformity. This planar seat provides uniform contact across the seat pan and does not attempt to shape or guide the pelvis to a particular alignment. When there are no pelvic or spinal deformities to accommodate, a flat, even surface supports comfortable, neutral sitting without introducing pressure points from a contour.

In contrast, a sling seat relies on fabric that forms a sagging surface and doesn’t provide a stable rigid base, which isn’t ideal for long-term postural support. A curved or contoured seat is used to accommodate pelvic obliquities or other deformities, shaping the surface to improve alignment and pressure distribution. A bevel front edge is a design feature to aid knee clearance or transfers, not a description of a seating surface that matches neutral alignment.