I have a 90 yr old grandfather who is sitting 90% of the time. He has sores on his bottom. Do you think Item #: GRL-201IMDMM the donut cushion will help him? or what do you recommend? The donut cushion would probably not provide sufficient level of comfort for your grandafather. You may wish to look into a wheelchair cushion. Wheel chair cushions are designed specifically for individuals who have to be in a seated position for an extended period of time. Please see our selection below: Wheelchair Cushions 12 in - 14 in Wheelchair Cushions 16 in - 18 in Wheelchair Cushions Bariatric 20 in - 30 in Wheelchair Cushions Whellchair Pads & High / Low Profile Cushions