Orthopedic Certified Specialist (OCS) Practice Exam 2026 - Free OCS Practice Questions and Study Guide

In exertional compartment syndrome, the anatomical structure most at risk of compression is the deep peroneal nerve. This condition occurs when the pressure within a closed muscle space rises, leading to decreased blood flow and potential nerve and muscle damage. In the anterior compartment of the lower leg, where the deep peroneal nerve resides, activities that increase muscle volume, such as running or strenuous exercise, can lead to significant increases in compartment pressure.

The deep peroneal nerve innervates muscles responsible for ankle dorsiflexion and toe extension. As the muscle fascia does not stretch, the increased pressure can compromise blood flow and nerve function, resulting in symptoms such as pain, weakness, and numbness in the affected area.

While other nerves may be anatomically close to different compartments, the deep peroneal nerve is the most closely associated with the anterior compartment, which is commonly affected by exertional compartment syndrome. Therefore, identifying this nerve highlights the risks associated with muscle swelling and the importance of timely intervention to prevent complications.