Which of the following areas is NOT commonly affected by compartment syndrome?

Compartment syndrome occurs when increased pressure within a closed anatomical space compromises the circulation and function of the tissues within that compartment. The condition is most commonly associated with areas of the body where muscle compartments are defined by fascia that does not stretch, such as in the thigh, lower leg, and foot. Each of these regions contains muscle groups that can swell due to injury, bleeding, or inflammation, leading to high intracompartmental pressure.

The upper arm is less frequently affected by compartment syndrome because it has a less rigid compartment structure compared to the lower leg and thigh. Additionally, arm injuries typically do not produce the same degree of swelling or muscle compartment pressure that is commonly seen in the lower extremities. While compartment syndrome can occur in the upper arm, it is much rarer, thereby explaining why it is the area not commonly affected compared to the other options listed.

Understanding the anatomical differences and potential for muscle swelling in these regions clarifies why the upper arm is less susceptible to this serious condition.