Which sites are commonly at risk for pressure sores in the supine position?

• A. Back of head
• B. Scapulae
• C. Spinous processes
• D. Sacrum

Answer: (D)

Prolonged external pressure over a bony area that has little cushion leads to tissue ischemia and potential ulcer formation. When a person lies on their back, the weight of the trunk rests directly on the sacrum. The sacral region has relatively thin soft tissue coverage and limited muscular padding, so sustained contact with the bed quickly compromises blood flow and tissue viability. That combination makes the sacrum the most common site for pressure sores in the supine position. Other areas like the back of the head or scapulae can be affected if padding is poor or the person remains immobile for a long time, but they’re less consistently involved than the sacrum. Spinous processes are typically well cushioned by surrounding muscles and tissue, so they’re less likely to develop pressure sores in this position.