Which ROM should be assessed when screening for ankle sprain risk?

• A. Plantarflexion ROM
• B. Knee extension ROM
• C. Dorsiflexion ROM
• D. Hip internal rotation ROM

Answer: (C)

Dorsiflexion range of motion is the key measure because limited dorsiflexion restricts the ankle’s ability to move forward over the foot during dynamic tasks like landing and cutting. When dorsiflexion is tight, compensations occur—such as early heel rise, extra subtalar pronation, and tibial rotation—that load the lateral ankle ligaments and increase the risk of an ankle sprain. Testing dorsiflexion, often with a weight-bearing lunge or knee-to-wall assessment, directly evaluates this function and helps identify risk.

Plantarflexion ROM is more about pushing off than controlling forward motion at contact, so it’s less predictive of ankle sprain risk. Knee extension ROM and hip internal rotation ROM relate to other joints and movement patterns, not the primary mechanics driving ankle sprain risk.