Anatomy, Range of Motion and Neutral Position of the Subtalar Joint The subtalar joint (STJ) allows triplanar motion of the foot relative to the leg. STJ pronation involves dorsiflexion, abduction and eversion of the foot relative to the leg. STJ supination involves plantarflexion, adduction and inversion of the foot to the leg. This triplanar motion of the STJ is important during human bipedal locomotion to allow the frontal plane motions of the foot to occur along with transverse plane motions