Exploring the Links Between Human Movement, Biomechanics & Gait
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.
Pain on the outside of the leg? Could it be your orthotic? What you wear on your feet amplifies the effect of the orthotic.
This woman presented with right-sided pain on the outside of her leg after hiking approximately an hour. She noticed a prominence of the arch in her right orthotic. She hikes in a rigid Asolo boot ( see below). Remember that footwear amplifies the effect of an orthotic!
In the pictures below you can see the prominent arch. The orthotic has her “over corrected” so that she toes off in varus on that side. The rigid footwear makes the problem worse. The peroneus group is working hard (Especially the peroneus longus) to try and get the first Ray down to the ground.
The “fix” was to soften the arch of the orthotic and grind some material out. Look at the pictures where the pen is pointing to see how some of the midsole material was taken out. Notice how I ground it somewhat medial to further soften the arch.
She felt better much better after this change and is now a “happy hiker” 🙂
This patient came in with pain at the base of the first metatarsal that she believed was related to her orthotic. The first picture shows the foots relationship to the orthotic. Notice how the sesamoid bones and distal aspect of the first metatarsal under lap the orthotic shell. In other words, the shell is longer than her foot. When she dorsiflexes her big toe, she’s hitting the distal of the orthotic.
The next view shows the orthotic with a typical first ray cutout. Notice how far forward the shell of the orthotic goes (next picture). I have placed a pen pointing to the area where the orthotic shell is too long.
In addition to reviewing her first ray descending exercises, a simple fix was to grind back the orthotic shell and be careful to bevel the edge so that it was not hitting the sesamoids and it did not impinge upon the descending first ray. I have placed a pen where the cut out now is (pre and post gluing in the pictures). The cork underlying the base of the first ray was also ground away (last picture)
A simple fix for a common problem. Make sure that your orthotic shell lengths fall just short of the 1st ray and not impinge on the sesamoids!
Gluteus minimus dysfunction is often present in gait disorders, including stance phase mechanical problems, since it fires from initial contact through pre swing, like it better known counterpart, the gluteus medius. It is interesting that the trigger point referral pattern of the gluteus minimus has a sciatic distribution, whereas the gluteus medius is more in the local area of the hip.
There are several, well known effects of dry needling:
decreased central sensitization
increased range of motion
changes in muscle activation
changes in the chemical environment surrounding a trigger point
changes in local and referred pain
and now we can add (not surprisingly), changes in autonomic function. The mechanism probably has something to do with pain and the reticular formation sending information down the cord via the lateral cell column (intermediolateral cell nucleus) or pain (nociceptive) afferents sending a collateral in the spinal cord to the dysfunctional muscle (Dr Ivo talks about these mechanisms in his dry needling and acupuncture lectures).
The presence of active TrPs within the gluteus minimus muscle among subacute sciatica subjects was confirmed. Every TrPs-positive sciatica patient presented DN related vasodilatation in the area of referred pain. The presence of vasodilatation suggests the involvement of sympathetic nerve activity in myofascial pain pathomechanism.
BMC Complement Altern Med. 2015; 15: 72. Published online 2015 Mar 20. doi: 10.1186/s12906-015-0587-6PMCID: PMC4426539 Intensive vasodilatation in the sciatic pain area after dry needling
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
This runner came in with ankle pain after running across the slope of the hill with the right foot uphill left foot down. She slipped on the ice and heard a pop. She presented to the office with minimal swelling, ankle pain on the right-hand side. Very little discoloration. She said that her ankle was “bent sideways” but reduced overtime as she crawled home to get help.
She slipped on the ice and heard a pop. She presented to the office with minimal swelling, ankle pain on the right-hand side. Very little discoloration. She said that her ankle was “bent sideways” but reduced overtime as she crawled home to get help.
The ankle was moderately swollen and tender at the medial and lateral malleoli with little gross deformity. She was not able to bear weight on that side without pain. We took the first picture (top) which didn’t look too bad. We could’ve stopped there thinking that it was just a bad sprain. But we didn’t… We always take three views of an area so we don’t miss things. You can plainly see in the second and third views that she has involvement of the deltoid ligament as well as the more obvious distal fibula fracture.
We did some acupuncture to do reduce swelling at the patient’s request and contacted the orthopedists office for her, placed her in the mobilization brace and give her some crutches.
When in doubt,take the shot. It can make a huge difference clinically.
Holy twisted tibias Batman! What is going here in this R sided knee pain patient?
In the 1st picture note this patient is in a neutral posture. Note how far externally rotated her right foot is compared to the left. Note that when you drop a plumbline down from the tibial tuberosity it does not pass-through or between the second and third metatarsals. Also note the incident left short leg In the next picture both of the patients legs are fully externally rotated. Note the large disparity from right to left. Because of the limited extra rotation of the right hip this patient most likely has femoral retro torsion. This means that the angle of her femoral head is at a greater than 12° angle. We would normally expect approximately 40° of external Rotation. 4 to 6° is requisite for normal gait and supination.
In the next picture the patients knees are fully internally rotated you can see that she has an excessive amount of internal rotation on the right compare to left, confirming her femoral antetorsion.
When this patient puts her feet straight (last picture), her knees point to the inside causing the patello femoral dysfunction right greater than left. No wonder she has right-sided knee pain!
Because of the degree of external tibial torsion (14 to 21° considered normal), activity modification is imperative. A foot leveling orthotic with a modified UCB, also inverting the orthotic is helpful to bring her foot somewhat more to the midline (the orthotic pushes the knee further outside the sagittal plane and the patient internally rotate the need to compensate, thus giving a better alignment).
a note on tibial torsion. As the fetus matures, The tibia then rotates externally, and most newborns have an average of 0- 4° of internal tibial torsion. At birth, there should be little to no torsion of the tibia; the proximal and distal portions of the bone have little angular difference (see above: top). Postnatally, the tibia should twist outward (externally) a total of 15 degrees until adult values are reached between ages 8 and 10 years of 23° of external tibial torsion (range, 0° to 40°). more cool stuff on torsions here
Got big toe pain? Think it’s gout? Think again! Things are not always what they appear to be.
This gent came in with first metatarsophalangeal pain which had begun a few months previous. His uric acid levels were borderline high (6) so he was diagnosed with gout. It should be noted his other inflammatory markers (SED rate and CRP) were low. Medication did not make the symptoms better, rest was the only thing that helped.
The backstory is a few months ago he was running in the snow and “punched through"the snow, hitting the bottom of his foot on the ground. Pain developed over the next few days and then subsided. The pain would come on whenever he try to run or walk along distances and he noticed a difficult time extending his big toe.
Examination revealed some redness mild swelling over the 1st metatarsophalangeal joint (see pictures above) and hallux dorsiflexion of 10°. If we raised the base of the first metatarsal and pushed down on the head of the 1st, he was able to dorsiflex the 1st MTP approximately 50°. He had point tenderness over the medial sesamoid. We shot the x-rays you see above. The films revealed a fracture of the medial sesamoid with some resorption of the bone.
The sesamoid fracture caused the head of the 1st metatarsal to descend on one side, and remain higher on the other, altering the axis of rotation of the joint and restricting extension. We have talked about the importance of the axis of this joint in may other posts (see here and here).
He was given exercises to assist in descending the first ray (EHB, toe waving, tripod standing). He will be reevaluated in a week and if not significantly improved we will consider a wedge under the medial sesamoid.
A pretty straight forward case of “you need to be looking in the right place to make the diagnosis”. Take the time to examine folks and get a good history.
Medial knee pain in a skier. Considering an orthotic? You had better know what you are doing!
Can you guess why this gal has pain in both knees? Especially when skinning up a hill and skiing down?
Take a close look at the photos above and notice the orientation of her knee with her foot. Now look at you tuberosity and drop a line straight downward. This line should pass through or slightly lateral to the second metatarsal shaft. Can you see how it falls to the outside of this? Perhaps even between the third and fourth metatarsal?
This gal has bilateral internal tibial torsion. When she wears a standard foot bed (creates a level surface for the right for the foot) or an orthotic without appropriate posting, it pushes her knee outside of the saggital plane. This creates abnormal patellofemoral tracking and appears to be a major contributor to her pain.
You will notice that we placed a valgus post under the orthotic( a post that is canted from lateral to medial) which pushes her knee to the midline as the first ray descends. You can see her alignment is better with her boots on and the changes.
The bottom line? Know your torsions and versions. Posting a patient like this incorrectly could result in a meniscal disaster!