Intratest reliability in determining the subtalar joint axis using the palpation technique described by K. Kirby.

Background: Exact determination and classification of the spatial position of the subtalar joint axis could be a predictive clinical variable in biomechanical analysis and a valuable tool in the design of functional foot orthoses.

Methods: Three clinicians with different levels of experience determined and classified the subtalar joint axis location, three times, on 52 individuals, using the clinical palpation, allocation and interpretation technique, as described by K. Kirby.

Results: High intratester precision (ICC 0.72 to 0.93) was found for determining the axis location (SEM, 3.72° for angle/0.27 cm for X-axis); however, classification of the spatial position of the axis has large intertester variation (κ = 0.243 to 0.494)

Conclusions: The clinical palpation technique itself is reliable; the consistent attribution of a classification, in other words, interpretation, is weak.