The Abductory Twist is a whip of the heel bone that can occur in some people during gait when the weight comes of the heel. It can be due to a foot that is overpronated past the middle of the stance phase or block at the first metatarsophalangeal joint.

Curated Resources:
http://www.runresearchjunkie.com/the-abductory-twist-during-gait/ (Run Junkie)
http://podiapaedia.org/wiki/biomechanics/clinical-biomechanics/biomechanical-assessment/gait-analysis/abductory-twist/ (PodiaPaedia)
https://podiatryarena.com/index.php?threads/abductory-twist.93483/ (Podiatry Arena)
http://www.epodiatry.com/abductory-twist.htm (ePodiatry)
https://podiatryarena.com/index.php?threads/abductory-twist.93483/ (Podiatry Arena)
http://podiatric.blogspot.com.au/2008/11/abductory-twist.html (Podiatry Update)
http://www.podiatryonline.tv/abductory-twist.htm (Podiatry TV)
http://foot-health-forum.com/index.php?tags/abductory-twist/ (Foot Health Forum)
http://www.podiatry-online.net/articles/the-abductory-twist-2.html (Podiatry Online)
http://www.podiatryexperts.net/uapage/10 (Podiatry Experts)

An abductory twist is the observation that is viewed during an observation of the running technique. As soon as the rearfoot starts to unweight or come off the surface there is a quick sudden abduction or twist noticed with the rearfoot. This is a frequent finding when doing a gait evaluation, however its clinical importance is of some debate.

There are a variety of explanations for this abductory twist. One is that since the foot is pronating (rolling medially at the rearfoot) this is trying to internally rotate the leg. At the same time the other leg is in the swing stage going forward and is endeavoring to externally rotate the leg. The leg is ‘battling’ with these two opposite forces. Friction between the ground and the rearfoot keeps the rearfoot from moving. Whenever load begins to come off the rearfoot, the external rotation power from above is now able to abduct the rearfoot and it does so rapidly. A second reason is that there is a problem at the great toe or hallux joint in which it will not allow dorsiflexion correctly. This could be a hallux rigidus, a functional hallux limitus or a issue with the windlass mechanism which affects motion at the big toe joint. As this motion is hard to start, the body abducts the heel to move medially about that joint. Another reason which is often only seen in the physiotherapy literature is that the observation is because of control of movement about the hip. In that literature it’s often described as a medial heel whip.

The cause of discussion about the clinical significance is that it is merely an observation viewed when doing a gait evaluation which is the result of another thing (for example, losing friction with the ground, a problem at the big toe or hallux joint or perhaps the hip joint). If it is a problem, then management is directed at what is creating the abductory twist or medial heel whip and not aimed at the abductory twist alone. The treatment options to do away with it is going to be very variable contingent upon what is the preferred management option for the cause.