Subtalar Joint Axis Rotational and Translational Motions During Closed Kinetic Chain Pronation and Supination - Sagittal Plane Motion In this three dimensional animation of the medial view of the weightbearing foot skeleton during closed kinetic chain subtalar joint (STJ) pronation and supination, the STJ axis is noted to undergo plantarflexion during pronation and dorsiflexion during supination. As the talus plantarflexes during STJ pronation, note how the STJ axis plantarflexes along with the