Rosh Emergency Medicine Practice Test

Which joint is primarily involved in the motion associated with the pathogenesis of an ankle sprain?

1. Distal tibiofibular joint

2. Subtalar joint

3. Talofibular joint

4. Tibiotalar joint

The correct answer is: Subtalar joint

The subtalar joint is primarily involved in the motion associated with the pathogenesis of an ankle sprain due to its role in foot inversion and eversion movements. During an ankle sprain, especially in the case of an inversion injury—which is the most common type—the ankle often rolls inward. This motion predominantly occurs at the subtalar joint, which is located below the talus and is crucial for the stability and movement of the foot during daily activities and athletic endeavors. This joint's mobility allows for the necessary adjustments during various activities, such as walking or running, where the foot may need to adapt to uneven surfaces. A sprain typically happens when there is a sudden twist or impact that forces the foot into an unstable position, causing sprain injuries specifically to the ligaments surrounding the ankle joint, particularly those associated with the subtalar motion. While the other joints mentioned are involved in the overall function and stability of the ankle, their primary involvement is more limited in the context of the mechanism of injury associated with typical ankle sprains. The distal tibiofibular joint is more about stability and does not directly contribute to the motion leading to sprains. The talofibular joint is often considered when discussing ligamentous injuries, but the subtalar joint