In the sitting position, which sites are commonly at risk for pressure sores?

• A. Scapulae
• B. Sacrum/coccyx
• C. Ischial tuberosities
• D. Popliteal

Answer: (C)

In sitting, pressure ulcers form where weight and pressure are concentrated over a bony area with limited padding, cutting off blood flow to the tissue. The ischial tuberosities—the sit bones at the base of the pelvis—directly bear the body's weight when you’re seated. They press against the chair with relatively thin overlying tissue, so prolonged sitting reduces blood flow and can lead to tissue damage and ulcers. That makes them the most common pressure-sore site in this position.

The sacrum and coccyx can be at risk if the person leans back or slumps, shifting weight to the sacral area for extended periods, but they’re not as consistently loaded as the sit bones in a typical seated posture. The scapulae are unlikely to be the primary pressure point unless you’re leaning hard against the backrest in a way that presses the shoulder blades into the chair, and the popliteal region isn’t a primary seated pressure site because it’s not normally bearing substantial weight in standard sitting.