Final answer:
Casts or splints can cause pressure ulcers by constricting blood vessels and creating friction on the skin.
Step-by-step explanation:
Casts or splints can cause pressure ulcers by a) constricting blood vessels and d) creating friction on the skin.
When a cast or splint is applied, it may put pressure on the surrounding blood vessels, restricting blood flow to the area. This can lead to tissue damage and the development of pressure ulcers.
In addition, the cast or splint can create friction on the skin, especially if it is not properly fitted or if there is excessive movement or rubbing against the cast. Friction can cause the skin to become irritated and susceptible to developing pressure ulcers.