Wow!  Can you figure out why this person at the distal end of her first metatarsal under her medial sesamoid.

She recently underwent surgery for a broken fibula (distal with plate fixation) and microfracrure of the medial malleolus. You are looking at her full range of dorsiflexion which is improved from approximately 20° plantarflexion. She is now at just under 5°.

She has just begun weight-bearing and developed pain over the medial sesamoid.

The three rockers, depicted above from Thomas Michauds book, or necessary for normal gait.  This patient clearly has a loss of ankle rocker. Because of this loss her foot will cantilever forward and put pressure on the head of the first metatarsal.  This is resulting in excessive forefoot rocker.  Her other option would have been to pronate through the midfoot. Hers is relatively rigid so, as Dr. Allen likes to say, the “buck was passed to the next joint. ”

There needs to be harmony in the foot in that includes each rocker working independently and with in its normal range. Ankle rocker should be at least 10° with 15° been preferable and for footlocker at least 50° with 65 been preferable.

 If you need to know more about rockers, click here.

Do you know where your rocker is?

At 1st pass, some articles may seem like a sleeper, but there can be some great clinical pearls to be had. I recently ran across one of these. It was a presentation from the  42nd annual American Academy of Orthotists and Prosthetists meeting in Orlando, March 2016 entitled “ Shifting Position of Shoe Heel Rocker Affects Ankle Mechanics During Gait”. The title caught my eye.

They looked at ankle kinematics while keeping the toe portion of rocker constant at 63% of foot length, angled at 25 degrees and shifting the base of a rockered shoe from 1cm behind the medial malleolus, directly under it and 1cm anterior to it. Knee and hip kinematics did not differ significantly, however ankle range of motion did.

The more forward the ankle rocker, the less plantarflexion but more ankle dorsiflexion at midstance. So, the question begs, why do we care? Lets explore that further…

  • Think about the “average” heel rocker in a shoe. It largely has to do with the length of the heel and heel flare (base) of the shoe. The further back this is (ie; the more “flare”) the more plantar flexion at heel strike and less ankle dorsiflexion (and thus ankle rocker, as described HERE) you will see. Since loss of ankle dorsiflexion (ie: rocker) usually means a loss of hip extension (since these 2 things should be relatively equal during gait (see here), and that combination can be responsible for a whole host of problems that we talk about here on the blog all the time. Picking a shoe with a heel rocker based further forward (having less of a flare) would stand to promote more ankle dorsiflexion.
  • Having a shoe with a greater amount of “drop” from heel to toe (ie: ramp delta) is going to have the same effect. It will move the calcaneus forward with respect to the heel of the shoe and effectively move the rocker posteriorly.
  • Lastly, look a the shape of the outsole of the shoe. The toe drop is usually clear to see, but does it have a heel rocker (see the picture above)?

These are  a few examples of what to look for in a clients shoe when examining theirs or making a recommendation, depending on whether you are trying to improve or decrease ankle rocker. We can’t think of why you would want to decrease ankle rocker, but with conditions like rigid hallux limitus, where the person has limited or no dorsiflexion of the great toe, you may want to employ a rockered sole shoe. We would recommend one with the rocker set more forward.

 Every foot has a story. 

 This is not your typical “in this person has internal tibial torsion, yada yada yada” post.  This post poses a question and the question is “Why does this gentleman have a forefoot adductus?”

The first two pictures show me fully internally rotating the patients left leg. You will note that he does not go past zero degrees and he has femoral retroversion. He also has bilateral internal tibial torsion, which is visible in most of the pictures. The next two pictures show me fully internally rotating his right leg, with limited motion, as well and internal tibial torsion, which is worse on this ® side

 The large middle picture shows him rest. Note the bilateral external rotation of the legs. This is most likely to create some internal rotation, because thatis a position of comfort for him (ie he is creating some “relief” and internal rotation, by externally rotating the lower extremity)

 The next three pictures show his anatomically short left leg. Yes there is a large tibial and small femoral component. 

 The final picture (from above) shows his forefoot adductus. Note that how, if you were to bisect the calcaneus and draw a line coming forward, the toes fall medial to a line that would normally be between the second and third metatarsal’s. This is more evident on the right side.  Note the separation of the big toe from the others, right side greater than left. 

Metatarsus adductus deformity is a forefoot which is adducted in the transverse plane with the apex of the deformity at LisFranc’s (tarso-metatarsal) joint. The fifth metatarsal base will be prominent and the lateral border of the foot convex in shape . The medial foot border is concave with a deep vertical skin crease located at the first metatarso cuneiform joint level. The hallux (great toe) may be widely separated from the second digit and the lesser digits will usually be adducted at their bases. ln some cases the abductor hallucis tendon may be palpably taut just proximal to its insertion into the inferomedial aspect of the proximal phalanx (1)

Gait abnormalities seen with this deformity include a decreased progression angle, in toed gait, excessive supination of the feet with low gear push off from the lesser metatarsals. 

 It is interesting to note that along with forefoot adductus, hip dysplasia and internal tibial torsion are common (2) and this patient has some degree of both. 

 His forefoot adductus is developmental and due to the lack of range of motion and lack of internal rotation of the lower extremities, due to the femoral retrotorsion and internal tibial torsion.  If he didn’t adduct the foot he would have to change weight-bearing over his stance phase extremity to propel himself forward. Try internally rotating your foot and standing on one leg and then externally rotating. See what I mean? With the internal rotation it moves your center of gravity over your hip without nearly as much lateral displacement as would be necessary as with external rotation. Try it again with external rotation of the foot; do you see how you are more likely displace the hip further to that side OR lean to that side rather than shift your hip? So, his adductus is out of necessity.

Interesting case! When you have a person with internal torsion and limited hip internal rotation, with an adducted foot, think of forefoot adductus!

1.  Bleck E: Metatarsus adductus: classification and relationship to outcomes of treatment. J Pediatric Orthop 3:2-9,1983.

2. Jacobs J: Metatarsus varus and hip dysplasia. C/inO rth o p 16:203-212, 1960

Forefoot valgus: A fixed structural defect in which the plantar aspect of the forefoot is everted on the frontal plane relative to the plantar aspect of the rearfoot; the calcaneum is vertical, the mid tarsal joints are locked and fully pronated

Want to know more? Join us Wednesday evening: 5 PST, 6 MST, 7 CST, 8 EST for Biomechanics 309: Focus on the forefoot on onlinece.com.

McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.

Fore foot types: Differences between forefoot varus and forefoot supinatus.

Certainly this can be a contraversial topic. Perhaps this will help clear up some questions.

Supination of the forefoot that develops with adult acquired flatfoot is defined as forefoot supinatus. This deformity is an acquired soft tissue adaptation in which the forefoot is inverted on the rearfoot. Forefoot supinatus is a reducible deformity. Forefoot supinatus can mimic, and often be mistaken for, a forefoot varus. A forefoot varus differs from forefoot supinatus in that a forefoot varus is a congenital osseous deformity that induces subtalar joint pronation, whereas forefoot supinatus is acquired and develops because of subtalar joint pronation (1).

A Forefoot Varus induces STJ pronation whereas a Forefoot Supinatus is created because of STJ pronation (2).

As the foot experiences increased subtalar joint (STJ) pronation moments during weightbearing activities (as in forefoot supinatus) , the medial metatarsal rays will be subjected to increased dorsiflexion moments and the lateral metatarsal rays will be subjected to decreased dorsiflexion moments. Over time, this increase in STJ pronation moments will tend to cause a lengthening of the plantar ligaments and medial fibers of the central component of the plantar aponeurosis and a shortening of the dorsal ligaments in the medial longitudinal arch. As a result, the influence of increased STJ pronation moments occurring over time during weightbearing activities will tend to cause the following (3):

1. An increase in inverted forefoot deformity.
2. A decrease in everted forefoot deformity.
3. A change in everted forefoot deformity to either a perpendicular forefoot to rearfoot relationship or to an inverted forefoot deformity.

More on the forefoot tomorrow evening on onlinece.com: Biomechanics 309. Join us!

1. Clin Podiatr Med Surg. 2014 Jul;31(3):405-13. doi: 10.1016/j.cpm.2014.03.009. Forefoot supinatus. Evans EL1, Catanzariti AR2.

2. https://kenva.wordpress.com/…/…/forefoot-varus-or-supinatus/

3. http://www.podiatry-arena.com/podiatry-forum/showthread.php…

Forefoot Varus or Forefoot Supinatus?

Forefoot varus is a fixed, frontal plane deformity where the forefoot is inverted with respect to the rearfoot. Forefoot varus is normal in early childhood, but should not persist past 6 years of age (i.e. when developmental valgus rotation of forefoot on rearfoot is complete, and plantar aspects of fore- and rearfoot become parallel to, and on same plane as, one another (1)

Forefoot supinatus is the supination of the forefoot that develops with adult acquired flatfoot deformity. This is an acquired soft tissue adaptation in which the forefoot is inverted on the rearfoot. Forefoot supinatus is a reducible deformity. Forefoot supinatus can mimic, and often be mistaken for, a forefoot varus. (2)

A forefoot varus differs from forefoot supinatus in that a forefoot varus is a congenital osseous where a forefoot supinatus is acquired and develops because of subtalar joint pronation.

“Interestingly, only internal rotation of the hip was increased in subjects with FV – no differences were present in hip adduction and knee abduction between subjects with and without FV. The authors nevertheless conclude that FV causes significant changes in mechanics of proximal segments in the lower extremity and speculate that during high-speed weight-bearing tasks such as running, the effects of FV on proximal segments in the kinetic chain might be more pronounced.”

We wonder if the folks in this study had a true forefoot varus, or actually a forefoot supinatus (3).

The Gait Guys

1. Illustrated Dictionary of Podiatry and Foot Science by Jean Mooney © 2009 Elsevier Limited.

2. Evans EL1, Catanzariti AR2. Forefoot supinatus.
Clin Podiatr Med Surg. 2014 Jul;31(3):405-13. doi: 10.1016/j.cpm.2014.03.009.

3. Scattone Silva R1, Maciel CD2, Serrão FV3. The effects of forefoot varus on hip and knee kinematics during single-leg squat. Man Ther. 2015 Feb;20(1):79-83. doi: 10.1016/j.math.2014.07.001. Epub 2014 Jul 12.

Forefoot Varus Anyone?

Forefoot varus appears to move the center of gravity medially while walking. Nothing earthshaking here, but nice to see the support of the literature.

“The most medial CoP of the row and CoP% detected increased medial CoP deviation in FV ≥ 8°, and may be applied to other clinical conditions where rearfoot angle and CoP of the array after initial heel contact cannot detect significant differences.”

We will be talking about foot types this week on onlinece.com; Wednesday 8 EST, 7 CST, 6MST, 5 PST Biomechanics 314. Hope to see you there!

J Formos Med Assoc. 2015 May 5. pii: S0929-6646(15)00132-1. doi: 10.1016/j.jfma.2015.03.004. [Epub ahead of print]
Analysis of medial deviation of center of pressure after initial heel contact in forefoot varus.

picture from: http://forums.teamestrogen.com/showthread.php?t=46901