If you use a wheelchair long term, switch to a pressure-relieving cushion and check the sitting bones and tailbone once a day

Moderate value
Evidence B
Buys life
Costs a little
Takes minutes
Some willpower

In plain words

An ordinary foam cushion, after long sitting, will break down the skin; once broken, it heals slowly and infects easily. Among nursing-home residents who used pressure-relieving cushions, pressure sores over the sitting bones were clearly fewer, but when the tailbone was counted together with them no difference was seen. The wheelchair itself should also be fitted to the person's size, not just bought as a generic model.

Cost: A pressure-relieving cushion costs a few hundred to over a thousand yuan. Checking once a day takes a minute.
What you get: This randomized clinical trial was done at 12 nursing homes. From 2004 to 2008 it recruited 232 residents aged over 65 who sat in a wheelchair more than 6 hours a day and had a Braden score under 18. Everyone was first fitted with a well-fitting wheelchair and then randomly split into two groups. One group used a skin-protection cushion (air, viscous fluid plus foam, or gel plus foam), and the other used a segmented foam cushion 7.6 cm thick. They were followed for 6 months or until a pressure sore developed. Pressure sores at the ischial tuberosity (sitting bone) occurred in 8 (6.7%) in the segmented foam group and 1 (0.9%) in the skin-protection cushion group, P=0.04. Counting the sitting-bone and sacrum/tailbone sores together, there were 21 (17.6%) in the segmented foam group and 12 (10.6%) in the skin-protection cushion group, P=0.14, which did not show a difference.
Notes: Graded B for two reasons. First, the sample was only 232 people, the main outcome's P value of 0.04 just passed the line, and the secondary outcome showed no difference. Second, the people studied were very old nursing-home residents, so applying it to younger wheelchair users is extending it beyond what it covers. In the trial everyone was first fitted with a well-fitting wheelchair, so “well-fitting” and “cushion” worked together; don't change only the cushion. For pressure-sore protection for people who stay in bed long term, with air mattresses and regular turning, see §17.8 (pressure sores). For how to apply for a subsidy for basic assistive devices, see §33.7 (go to the county Disabled Persons' Federation and ask about everything).
Evidence grade: B : Supported by research but without a precise number, or based on small or single studies.
Sources: Brienza D, Kelsey S, Karg P, et al. (2010). A randomized clinical trial on preventing pressure ulcers with wheelchair seat cushions. Journal of the American Geriatrics Society, 58(12):2308-2314. https://doi.org/10.1111/j.1532-5415.2010.03168.x

Translated from the Chinese original. Original book, section 33, tip 5. Content may be out of date and rules differ by place. When you actually deal with an agency, a doctor or a court, follow what local officials, doctors and lawyers tell you. Disclaimer