When checking for rigid or supple flat feet, which anatomical landmark is used and which test confirms the finding?

When checking for rigid or supple flat feet, which anatomical landmark is used and which test confirms the finding?

• A. Navicular Tubercle , Navicular drop test
• B. Tubercle of the 5th metatarsal , Haglunds' test
• C. Calcaneus , Calcaneal eversion measurement test
• D. Neck of the Talus , Severs' test

Answer: (A)

Assessing flat feet relies on the navicular bone as a reliable marker of arch height. The navicular tubercle is the palpable landmark used on the medial midfoot. To distinguish rigid from supple flat feet, perform the navicular drop test: measure the height of the navicular tubercle from the floor when the foot is non-weight-bearing (seated), then measure again with the patient standing (weight-bearing). A significant drop in navicular height indicates the arch collapses under load, meaning a supple flat foot, whereas little or no drop points to a rigid flat foot. This combination of landmark and test directly differentiates how the arch behaves with weight-bearing. Other options refer to landmarks or tests for different conditions, such as Haglund’s deformity or retrocalcaneal issues, and do not assess arch flexibility.

Assessing flat feet relies on the navicular bone as a reliable marker of arch height. The navicular tubercle is the palpable landmark used on the medial midfoot. To distinguish rigid from supple flat feet, perform the navicular drop test: measure the height of the navicular tubercle from the floor when the foot is non-weight-bearing (seated), then measure again with the patient standing (weight-bearing). A significant drop in navicular height indicates the arch collapses under load, meaning a supple flat foot, whereas little or no drop points to a rigid flat foot. This combination of landmark and test directly differentiates how the arch behaves with weight-bearing. Other options refer to landmarks or tests for different conditions, such as Haglund’s deformity or retrocalcaneal issues, and do not assess arch flexibility.