An abductory twist is an observation which is noticed during an observation of the running. Just as the heel begins to unweight or raise up the floor there’s a quick sudden abduction or twist noticed of the heel. This is a commonplace finding during a gait evaluation, however its clinical relevance is actually of some question.
There are a number of reasons for this abductory twist. One is that because rearfoot is pronating (moving inwards at the rearfoot) this is attempting to internally turn the leg. While doing so the other leg is in the swing phase moving forward and is attempting to externally rotate the lower limb. The lower limb is ‘battling’ with these two opposite forces. Friction between the ground and the foot keeps the heel from moving. Immediately after force begins to come off the heel, the external rotation force from above is now able to abduct the rearfoot and it does so rapidly. A second explanation is that there is a condition at the great toe joint in which it does not enable dorsiflexion correctly. This might 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 difficult to begin, the body abducts the heel to move medially about that joint. A third reason which is often only found in the physical therapy literature is that the twist is due to control of motion about the hip joint. In that literature it is often described as a medial heel whip.
The cause of debate around the clinical importance is that it is merely an observation seen when doing a gait analysis that is caused by something else (ie, losing friction with the ground, a problem at the great toe joint or maybe the hip joint). If it is a concern, then management is directed at what is creating the abductory twist or medial heel whip rather than directed at the abductory twist alone. The management options to get rid of it is going to be very variable dependent on what is the best management decision for the reason.