Understanding the Feiss Line Test (or Feiss Line Grading) Assessment
To clinically assess and grade the degree of **longitudinal arch collapse (Pes Planus or Flat Foot)**.
Watch How It's Done
How do I start?
Patient is sitting with the ankle in neutral, non-weight bearing.
What happens?
The examiner marks three points: the apex of the **medial malleolus**, the **navicular tuberosity**, and the head of the **first metatarsal**. A line (Feiss Line) is drawn between the malleolus and the metatarsal head. The patient is then asked to stand.
In Plain English
What Does a Positive Result Mean?
The **navicular tuberosity drops below the Feiss Line** upon weight-bearing. **Grade 1:** Drop is 1/3 of the distance to the floor. **Grade 2:** Drop is 2/3 of the distance. **Grade 3:** Navicular tuberosity rests on the floor.
Helpful Tip:
Measures flexible flatfoot severity. A greater drop indicates increased arch collapse.
Safety First
This guide is to help you understand what happens in a clinic. Do not try to diagnose yourself. If you have severe pain, swelling, or cannot put weight on your leg, please visit an urgent care center or your doctor immediately.
Other Foot Tests
Coleman Block Test
To assess the **flexibility of a hindfoot varus deformity** and determine if it is fixed (bony) or flexible (soft tissue) in a patient with a **Cavus Foot (High Arch)**.
External Rotation Stress Test (Syndesmosis Ligament Test)
To assess the integrity of the **Distal Tibiofibular Syndesmosis** (high ankle sprain ligaments) by applying a rotational stress.
Navicular Drop Test (or Staheli's Arch Index)
To quantify the change in height of the **medial longitudinal arch** from non-weight bearing to full weight bearing (assessing flexible flatfoot).
Toe Spread Test
To assess the **strength and endurance of the intrinsic foot muscles** (IFMs), which are essential for arch stabilization and dynamic balance.