Are you a caretaker?
From what I have been reading, bed sores or pressure sores may be common for those that are either bed ridden or are confined to a wheelchair. The sores are usually prominent for areas which are boney such as the buttock (tail bone). They are caused by pressure or friction. If you have an individual who is also bowel or bladder incontinent, the extra moisture doesn't help any.
Here is one article about bed sores here which you can review.
But the best information comes from The National MS Society with regard to pressure sores caused by MS.
They suggest that to prevent these sores from happening or becoming worse, that the person's position should be changed at least once every two hours.
They also offer this advice with regard to wheelchair use:
"If you use a wheelchair, it is important that you sit on a cushion that distributes your weight. A gel-filed cushion is often recommended. Ask your physician or physical therapist about an evaluation by a seating specialist. Sitting on pillows, towels, or foam pads may add to your risk of developing pressure sores."
The treatment for pressure sores seem dependent upon how severe the sores are. The treatments range from simply relieving the source of pressure, to dressing the wound and using antibiotics, to surgery.
Definitely a doctor's guidance is needed to adequately treat these pressure sores.
I hope this helps some. Good luck to you and thank you for your question.