m certainly no expert, but I will say since you mentioned he is wheelchair bound, then
pressure is exerted on
pressure points on his feet. If he has spasticity and his
foot is pressing on certain aspects of his foot (ie: lateral/side, heels, ball of feet, etc.) then what that does is decrease blood flow to that area and can cause ulcerations after consistent pressure. It is even worse if his protein levels (albumin) are low.