More on the scourge of Flip Flops. Riding the inside edge of the sandal. Mystery hunting with Dr. Allen.

Tis the season upon us. Riding the inside edge of the sandal.
You can see it in the photo, the heel is a third of the way off the sandal.

You either have it or have seen it. It is frustrating as hell if you have it. Your heel rides on only half of your flip flop or summer sandals. You do not notice it in shoes, only in sandals, typically ones without a back or back strap. This is because the heel has no controlling factors to keep it confined on the rear of the sandal sole. There is no heel counter on open backed shoes and sandals, the counter keeps the heel central on the back of the footwear. There is a reason this inside edge riding happens to some, but not everyone. It is best you read on, this isn’t as simple as it might seem.

These clients may have restricted ankle rocker (dorsiflexion), restricted hip extension and/or adductor twist (if your reference is the direction the heel is moving towards). I could even make a biomechanical case that a hallux limitus could result in the same scenario. So what happens is that as the heel lifts and adducts it does not rise directly vertically off the sandal, it spins off medially from the “adductor twist” event. This event is largely from a torque effect on the limb from the impaired sagittal mechanics as described above, manifesting at the moment of premature heel rise resulting in an slightly externally rotating limb (adducting heel). The sandal eventually departs the ground after the heel has risen, but the sandal will rise posturing slightly more laterally ( you can clearly see this on the swing leg foot in the air, the sandal remains laterally postured). Thus, on the very next step, the sandal is not entirely reoriented with its rear foot under the heel, and the event repeats itself. The sandal is slightly more lateral at the rear foot, but to the wearer, we believe it is our heel that is more medial because that is the way it appears on the rear of the sandal or flip flop. Optical illusion, kind of… . . a resultant biomechanical illusion is more like it.

You will also see this one all over the map during the winter months in teenagers who swear by their Uggs and other similar footwear, as you can see in the 2nd photo above. This is not an Ugg or flip flop problem though, this is often a biomechanical foot challenge that is not met by a supportive heel counter and may be a product of excessive rear foot eversion as well. This does not translate to a “stable” enough shoe or boot, that is not what this is about. This is about a rearfoot that moves to its biomechanical happy place as a result of poor or unclean limb and foot biomechanics and because the foot wear does not have a firm stable and controlling heel counter. This is not about too much pronation, so do not make that mistake. And orthotic is not the answer. A heel counter is the answer. The heel counter has several functions, it grabs the heel during heel rise so that the shoe goes with the foot, it give the everting rearfoot/heel something to press against, and as we have suggested today, it helps to keep the rearfoot centered over the shoe platform. To be clear however, the necessary overuse and gripping of the long toe flexors to keep flip flops and backless sandals on our feet during the late stance and swing phases of gait, clearly magnifies these biomechanical aberrations that bring on the “half heel on, half heel off” syndrome.

There you have it. Another solution to a mystery in life that plagues millions of folks.

Shawn Allen, the other gait guy

Riding the inside edge of the sandal. Mystery hunting with Dr. Allen.

You can see it in the photo above, the heel is a third of the way off the sandal. (there are 2 photos provided today, find the arrow and tab to see both)

You either have it or have seen it. It is frustrating as hell if you have it. Your heel rides on only half of your flip flop or summer sandals. You do not notice it in shoes, only in sandals, typically ones without a back or back strap.  This is because the heel has no controlling factors to keep it confined on the rear of the  sandal sole. But there is a reason this happens to some, but not everyone. It is best you read on, this isn’t as simple as it might seem. 

These clients have restricted ankle rocker (dorsiflexion), restricted hip extension and/or adductor twist (if your reference is the direction the heel is moving towards). I could even make a biomechanical case that a hallux limitus could result in the same scenario. So what happens is that as the heel lifts and adducts it does not rise directly vertically off the sandal, it spins off medially from the “adductor twist” event. This event is largely from a torque effect on the limb from the impaired sagittal mechanics as described above, manifesting  at the moment of premature heel rise resulting in an slightly externally rotating limb (adducting heel). The sandal eventually departs the ground after the heel has risen, but the sandal will rise posturing slightly more laterally ( you can clearly see this on the swing leg foot in the air, the sandal remains laterally postured). Thus, on the very next step, the sandal is not entirely reoriented with its rear foot under the heel, and the event repeats itself. The sandal is slightly more lateral at the rear foot, but to the wearer, we believe it is our heel that is more medial because that is the way it appears on the rear of the sandal or flip flop.  Optical illusion, kind of… . . a resultant biomechanical illusion is more like it.

You will also see this one all over the map during the winter months in teenagers who swear by their Uggs and other similar footwear, as you can see in the 2nd photo above. This is not an Ugg or flip flop problem though, this is often a biomechanical foot challenge that is not met by a supportive heel counter and may be a product of excessive rear foot eversion as well.  This does not translate to a “stable” enough shoe or boot, that is not what this is about. This is about a rearfoot that moves to its biomechanical happy place as a result of poor or unclean limb and foot biomechanics and because the foot wear does not have a firm stable and controlling heel counter.  The heel counter has several functions, it grabs the heel during heel rise so that the shoe goes with the foot, it give the everting rearfoot/heel something to press against, and as we have suggested today, it helps to keep the rearfoot centered over the shoe platform.  To be clear however, the necessary overuse and gripping of the long toe flexors to keep flip flops and backless sandals on our feet during the late stance and swing phases of gait, clearly magnifies these biomechanical aberrations that bring on the “half heel on, half heel off” syndrome.

There you have it. Another solution to a mystery in life that plagues millions of folks. 

Dr. Shawn Allen, mystery hunter, and one of the gait guys.

Pronating around internal hip rotation loss.

This is a remedial principle, but it is always nice to capture it on video like this. Watch this clients left foot. On initial impressions you might just say too much foot pronation, and you would be right. Some of you might say abductor-adductor twist of the foot. These are all correct. But, if we told you that this was a hip complaint client, and lack of internal hip rotation this foot action should be a simple 60Watt “light bulb moment” (translation: “epiphany”), certainly not a 100Watt moment (but for some it might be).  

This client cannot internally rotate through the hip adequately, so they have found the opposite end of the limb to internally rotate through.  They collapse through the arch/tripod, which essentially in the crudest of analogies “internally screws the limb” into the ground.  They are finding internal femur rotation through foot pronation.  Internal hip rotation is being achieved from a bottom up process if you will. Pronation through the foot complex is adduction, medial rotation and plantarflexion of the talus which will carry the tibia (and thus the femur) with it into internal rotation.  There is a problem in many clients who find that extra little bit of rotation at the hip via a foot/ankle cheat.  That problem is one of corruption of the pelvis antiphasic motion of the pelvis, they will most often dump the same hip laterally and thus drift into the frontal plane instead of achieving the antiphasic motion of the pelvis.  This will decouple the rotation of the torso in the opposite rotation of the pelvis, and thus begin the corruption of arm swing.  Want to take it another level deeper ? Ok, eat this for lunch……. asymmetrical thoracic rotation from side to side will set up. This will mean more work through scapulothoracic stabilization and cervical rotation on the side of the thoracic rotation deficit.  Still not deep enough ? Ok, evaluate their respiration symmetry.   Too many are doing respiratory work before hip rotation is clean and symmetrical, especially during gait that necessitates 1000′s of engraining steps a day.  If the hips are not clean, gait is not clean, and that means repetitive arm swing-thoracic-respiratory mechanics are not clean.

If you want to truly fix someones rooted problems, you have to be willing and able to go down the rabbit hole. 

Shawn Allen, one of the gait guys

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

Ankle Dorsiflexion: Even in sprinters who land on the forefoot often heel strike, a retrograde strike if you will.

Many people think of heel strike followed by midfoot/tripod contact phase followed by ankle dorsiflexion, aka ankle rocker.  Heel strike is normal in the walking gait cycle. In some runners, depending on foot type, strength, flexibilty and several other factors, heel strike may be considered normal and may be essential for normal injury free mechanics. However, in recent years we tend to see the media and research investigate a midfoot or forefoot strike pattern. If you have been here with us on TGG for a year or 2-3 you will know we are big advocates of a midfoot strike pattern for several reasons which we will not go into again in this article. (Feel free to SEARCH our blog for MIDFOOT strike articles).  

However, one rarely sees anyone or any source talking about the retrograde heel contact when forefoot strike patterns are used.  Here, in this video, you can see several of these top level athletes who are trying to go forward at top end speed, but who are tapping the heel down on many loading responses. This can be thought of as a retrograde movement and could in a biomechanical way of thinking be considered non-productive. In other words, they are trying to move forward and yet the heel is touching down which is a backwards movement. This point can be argued but that is not the point of this article. The point that we are trying to make is that in order to drop the heel down, and especially if the heel touches, that the runner had better have sufficient ankle rocker/dorsifleixon otherwise the arch may be asked to collapse via excessive pronation (to perform the heel tap) which will drive an internal spin movement when the leg is supposed to be externally rotating to a rigid supinated foot for propulsive toe off. This negative scenario is a huge power leak for a sprinter, or any runner for that matter when they are ramping up speed.  

So, why does this happen ?  Well, for some it can help to load the posterior mechanism, the gastrocsoleus-achilles complex for conservation and power conversion.  It also enables more hip extension and thus more gluteal function. Longer stride means more efficient and greater arm swing which is a huge accessory power source for a sprinter. This also lengthens the stride, they feed off of each other. There are many benefits, if you have sufficient ankle rocker range in the ankle to begin with.  In some runners who do not have the requisite ankle rocker range, you may often see the increased foot progression angle and external limb spin and/or the dreaded adductor twist of the heel (aka  abductory twist of the foot).  These are strategies to get more hip extension and more gluteal function without finding it via the ankle dorsiflexion, where you want to see it.  Remember, the body is a brilliant compensatory and substituter. If the body cannot find a range at one joint it will find it at the next proximal or distal joint. And when that loss is at the ankle, motor patterns options dictate you either find it at foot pronation or hip extension.

Maybe, just maybe we should have called this blog article “Can you hold the foot tripod all the way through the stance phase, even through retrograde heel touch down ? If you cannot, trouble could be on the horizon. ”  But that is a really dumb title.  

Shawn and Ivo

the gait guys