Could someone explain to me the biomechanics of abductory twist?
Two possible reasons: 1. Foot pronates beyond midstance–> internal rotation moment to leg; the opposite leg is swinging forward and rotating the pelvis –> externally rotation moment to leg on ground –> conflict between proximal external rotation and distal internal rotation moments — initially the pronated foot causing the internal rotation moment wins the battle and foot does not resupinate to accommodate that proximal external rotation moment ….. eventually as heel comes off ground, friction between the ground and foot can no longer no longer resist the external rotation moment coming from above –> abductory twist 2.