The Abductor Heel Twist: Look carefully, it is here in this video.
This should be a simple “piece it together” video case study for you all by this point. This young lad came into our office with left insertional achilles pain of two weeks duration after starting some middle distance running.
What do you see here ? It is evident on both the right and the left, but it is a little more obvious on the left and can be seen on the left when he is walking back toward the camera as well. You should see rearfoot eversion, it is excessive, and a small rearfoot adductor twist. Meaning, the heel pivots medially towards the midline of his body. Some sources (Michaud) call this an Abductory Twist, but the reference there is typically the forefoot. Regardless, to help our patients, we sometimes refer to this is “cigarette butt” foot. It is like stepping on a lit cigarette to put it out via twisting/grinding it into the ground.
So, now that you can see this, what causes it?
The answer is broad but in this case he had a loss of ankle dorsiflexion range. The ankle mortise clearly did not have enough of ankle rocker range during midstance so as that limitation was met, the heel raised up prematurely during the moments when the opposite leg is in full swing imparting an external rotation on the stance limb (hence the external foot spin (adducting heel/abducting foot……depending on your visual reference)). There is a bit more to it than that, but that will suffice for now because it is not the central focus of our lesson today.
What can cause this ? As we said, a broad range of things:
- hallux limitus
- flexion contracture of the knee (swelling, pain, joint replacement etc)
- short calf-achilles complex
- weak tib anterior and extensor toe muscles
- Foot Baller’s ankle
- limited/impaired hip extension
- weak glute (minimizing hip extension range)
- sway back (lower crossed syndrome-type biomechanics)
- short quadriceps (similarly impairing hip extension)
- flip flop excessive use (or any other motor strategy that imparts more flexor compartment dominance (read: calf-achilles, FDL)
- excessive pronation
- impaired foot tripod mechanics
- etc
The point is that anything impairing TIMELY (the key word is timely) forward sagittal gait mechanics can, and very likely will, impair ankle rocker. Even the wrong shoe choice can do this (ie. someone who suddenly drops from a 12 mm heel ramped shoe into a 0-4mm ramped heel shoe and who thus may not have earned the length of the calf-achilles complex as of yet).
The abductor-adductor twist phenomenon is not a normal visual gait observation. It is a softly seen, but screaming loud, pathologic gait motor pattern that must be recognized. But, more importantly, the source of the problem must be found, confirmed and resolved. In this fella’s case, he has some weakness of the tib anterior and extensor toe muscles that has lead to compensatory tightness of the calf complex. There was no impairment of the glutes or hip extension, as this was just 2 weeks old or so, but if left unaddressed much longer the CNS would have likely begun to dump out of hip extension and gluteal function to protect……another compensation pattern. Remember, ankle rocker and hip extension have a close eye on each other during gait.
Clinical pearl for the true gait geeks…… if you see someone with a vertically bouncy forefoot-type gait (you know, those people that bounce up and down the hallway at work or school) you can usually suspect impaired ankle rocker and if you look closely, you will usually see a quick abductor-adductor twist.
Shawn and Ivo
the gait guys
