Patent ID: 7249802

Claim:
A backrest for a seat structure, the backrest comprising: a frame member; a compliant, resilient back member having a top, a bottom and opposite sides, wherein said back member is mounted to said frame member, said back member comprising a lumbar region, a thoracic region disposed above said lumbar region, and a lower region disposed below the lumbar region, wherein said lumbar region comprises a first array of openings formed therethrough, said first array comprising a first plurality of staggered, elongated openings, wherein said first plurality of said first array openings are elongated in a direction from the top to the bottom of the back member, and wherein said thoracic region comprises a second array of openings formed therethrough, said second array comprising a second plurality of staggered, elongated openings, wherein said second plurality of said second array openings are elongated in a direction from the top to the bottom of the back member, wherein said first plurality of openings have a greater elongation on average than said second plurality of openings, and wherein second plurality of staggered, elongated openings comprises at least two adjacent vertical columns of openings, wherein said adjacent vertical columns of openings are offset in a vertical direction from said top to said bottom of said back member such that said openings in said adjacent vertical columns are not horizontally aligned.