The habitual adoption of certain gestures and postural habits can result in a variety of non-metric traits, including supernumerary facets that are both articular and non-articular. The squatting facet is a classical example of the former, and generally presents as a lateral articular facet on the neck of the talus that articulates with a facet on the anterior border of the distal tibia. These facets arise owing to the adoption of the squatting position and the hyperdorsiflexed position of the ankle joint, bringing the talus and tibia into immediate approximation. This study reports on the difference between the classical squatting facet and a non-articular facet, which can also present on the neck of the talus but occurs, probably, as a result of soft tissue pressure, rather than bony articulation. It is suggested that whilst the function of the two facets may be similar, their aetiology is likely to be very different. Copyright © 2001 John Wiley & Sons, Ltd.