During the Feiss Line assessment, what is assessed to determine the amount of pronation?

The Feiss Line assessment is specifically designed to evaluate the position of the navicular bone relative to the medial malleolus and the first metatarsal head while assessing the impact of weight-bearing on foot structure. The primary focus of this assessment is to measure the navicular drop, which indicates how much the navicular bone lowers in relation to the established baseline when a person transitions from a non-weight-bearing to a weight-bearing position.

This navicular drop serves as an objective measure of pronation, where increased drop signifies greater pronation. By examining this change, clinicians can determine the extent of flatfoot deformity or excessive pronation, which can help guide treatment plans for conditions like plantar fasciitis, tibialis posterior dysfunction, or other related pathologies.

The other choices listed do not specifically correlate with the intended assessment of pronation via the Feiss Line. Range of motion of the ankle, while important for overall foot and ankle mechanics, does not directly indicate the degree of pronation. Pain levels in the forefoot can provide insight into a patient’s experience but do not measure structural changes in the foot. Similarly, calf muscle strength is relevant to overall biomechanics but does not address the specific relationship between the navicular bone and the mechanisms