Navicular drop is a measurement that is used to determine how much the navicular moves between the neutral and relaxed positions of the foot.
The Navicular Drop test is a physical examination technique used to assess the mobility and stability of the foot’s arch, specifically the medial longitudinal arch. The test provides information about the extent of pronation or collapse of the arch when weight is placed on the foot. Here’s how the Navicular Drop test is performed:
- Preparation: The individual being tested should be standing barefoot on a flat surface, such as an examination table or the floor.
- Marking the Navicular Tuberosity: The examiner locates the navicular tuberosity, which is a bony prominence on the inside of the foot, just above the arch. This point serves as a reference for measurements.
- Measurement in Neutral Position: The examiner measures the vertical distance between the floor or surface and the navicular tuberosity while the individual is in a relaxed, standing position with equal weight distributed on both feet. This is the baseline measurement of the foot’s arch height.
- Measurement in Subtalar Joint Pronation: The examiner instructs the individual to roll the foot inward or pronate the subtalar joint. This motion causes the arch to lower or collapse. The examiner then measures the vertical distance between the floor or surface and the navicular tuberosity in this pronated position.
- Navicular Drop Calculation: The Navicular Drop is calculated by subtracting the measurement in the pronated position from the baseline measurement in the neutral position. The result represents the amount of arch collapse or pronation that occurs when weight is placed on the foot.
The Navicular Drop test is commonly used in sports medicine, orthopedics, and podiatry to assess foot biomechanics, specifically related to overpronation. Excessive navicular drop may indicate decreased arch stability and can be associated with various foot and lower limb conditions, such as flat feet, plantar fasciitis, shin splints, and patellofemoral pain syndrome.