The Case of the Non Rotating Knee

Here is a runner, wanting to be an ultra runner, who recently developed right sided knee pain while running a 50K. He was pacing another individual and developed pain on the outside (lateral patella and knee) on the right, ascending and especially descending hills. The pain is dull and achy. He is able to “push through” the pain, but if he does, it remains painful for a few days.

He has an anatomically short leg on the L (tibial). There is no significant tibial torsion (he has normal external version) and not femoral torsion. There are adequate amounts of internal (>15 degrees) and external (>30 degrees) rotation of the hips.

He has 7 degrees ankle dorsiflexion on the right, 10 degrees on the left. On the table (and in the video) he has 0 degrees of hip extension during passive motion, walking and running. He has weakness of the long extensors of the toes, as well as the abductors.

Take a look at his video. Note the following:

·       the right knee has less medial excursion than the left (watch the dots)

·       rearfoot valgus is noted on the L  (ie. calcaneus is everted)

·       subtle lean to Left on L sided stance phase

·       when barefoot, the problem lessens

Why does the right knee rotate less than the left?

When folks have a short leg, we generally expect that leg to remain in supination (thus external rotation) more and the longer leg to internally rotate more, due to excessive pronation. But here, we see the opposite. You will notice he has a rearfoot valgus on the left. This means the midtarsal joint is in a greater amount of pronation on the shorter side. For every action, there is an equal and opposite reaction. In this case, less pronation (or supination) on the longer leg side. Remember, we said generally folks pronate more on the long leg side. This is one of the exceptions.

So, should he throw away his shoes?

The shoes, which have a certain amount of torsional rigidity, are compounding the problem. The Brooks Cascadia is an excellent trail running shoe, he just needs something with less torsional rigidity. the shoe does  not allow his knee to come midline sufficiently. Since he is a Brooks Fan, we suggested the “Grit” in the Pure line. 4mm drop and less rigid torsionally. He could also work his way into a “Drift” (4mm or zero drop, extremely flexible).

Why does he lean to the left on stance phase on the left?

Most likely, to clear the right long leg on swing phase. This is one of the 5 common strategies. For more strategies, click here.

Why is it better when he is barefoot? It must mean he should be a barefoot runner, right?

He is better, because there is less impediment to the foot pronating (ie. the shoe has less torsional rigidity)

The Gait Guys. Making you a better diagnostician, with each and every post.

More proof for the Cross Over Gait for the non-believers and debaters.

For those of you who have been with us for a few years, you are no stranger to our articles and videos on the web for piecing together many aspects of the CROSS OVER GAIT in a manner more comprehensive and more clear.  If you are not familiar with our work on this, please click here.

Today we add a little more “proof to our pudding”.

“Changing step width alters lower extremity biomechanics during running.” Brindle et al.
http://www.gaitposture.com/article/S0966-6362(13)00291-9/abstract

• Step width influences frontal plane biomechanics of all body parts
• Changes in step width affects arm swing symmetry and often creates arm abduction
• Hip and knee biomechanics change from their normal predicted path and mechanics
• Hip adduction, rearfoot eversion and internal tibial spin decrease as step width increases
• Knee adduction/valgus stress decreases as step width increased.
• Increased step width improves cephalad stacking of all lower extremity joints
• The swing limb is a hinging pendulum. Striving for a level pelvis and normal step width promotes a normal sagittal pendulum path and improves the likelihood of a recurring sagittal pendulum swing for the opposite leg. 

As Brinkle et al. say in their paper, “step width is a spatiotemporal parameter that may influence lower extremity biomechanics at the hip and knee joint.”  We would argue that it is even more far reaching than the hip and knee. You have likely learned here at the Gait Guys that arm swing is heavily predicated on the dynamics of contralateral leg function and positioning.

The above video shows a classic cross over gait. The limbs can be seen crossing over the midline thus guaranteeing that the pendulum is moving through an arc and not along a straighter progression. This adduction of the limb virtually guarantees that the foot is striking greater on the lateral heel and forefoot than it should, that the rear foot is going to move through eversion with greater speed and force and internal tibial spin and arch control will need to be controlled better.  And if they are not controlled better, pathology may eventually occur.  Do you want any of this to occur at an accelerated rate as occurs in running ? One doesn’t need to just heel strike to suffer these problems, midfoot strike will still see them if the cross over occurs.

Shawn and Ivo, the Cross Over Guys.

What’s your Foot Type? : Part 2

Welcome to Monday! Here is the next in the series…

Rearfoot valgus.

Remember the foot tripod? It consists of the the 3 points: the base of the 1st metatarsal (under the sesamoids), the base of the 5th metatarsal, and the calcaneus. In this foot type the rear leg of the tripod is compromised as the rear foot collapses medially (the heel or calcaneus,  everts or moves laterally) causing subsequent collapse of the arch and midfoot.

This foot type causes an excessive internal rotation strain on the lower kinetic chain, often with collapse of the knees inward (genu valgum or “knock knees”). Due to the midfoot collapse, the deep calf muscles are typically overused and strained leading to medial ankle region tendonopathies, as they attempt to slow the rate of pronation and arch collapse.

This foot type has a difficult time going from pronation to supination to prepare for a rigid foot push off in the propulsive phase. Because the lower limb is internally rotated so much, the external rotators are over burdened leading to fatigue and weakness of the glutes and shortening of the TFL, leading to the chronic IT Band syndromes. Low back pain is common because of forward tip of the pelvis.

2 down, 3 to go!

Confused between the ear?

Have no fear. Shed no tear.

Our shoe fit program is almost here!     (Everyone has a little Dr. Seuss in them)

The Shoe fit functional testing module (also available separately from the 3 part program) discusses foot types in more detail.

The Gait Guys: promoting foot and gait competency everywhere!

Clinical Video Case Study: Tibial Varum with added Post-op ACL complications.

This is a case of ours. This young man had a left total knee reconstruction (Left ACL and posterolateral compartment reconstruction; allograft ligaments for both areas). This video is roughly 3 months post surgery.

Q: What anatomical variants are seen in this individual?

A: Note the genu and tibial varum present. This results in an increased amount of pronation necessary (right greater than left, because of an apparent Left sided short leg length;

* NOTE: post-operatively at this point the client had still some loss of terminal left knee extension. thus the knee was in relative flexion and we know that a slightly flexed knee appears to be a shorter leg. Go ahead, stand and bend your left knee a few degrees, the body will present itself as a shorter leg on that left side with all the body compensations to follow such as right lateral hip shift and left upper torso shift to compensate to that pelvic compensation.)

Normally, in this type of scenario (although we have corrected much of it at this point by giving him more anterior compartment strength and strategy as evidenced by his accentuated toe extension and ankle dorsiflexion strategies, these are conscious strategies at this point for the patient), the functionally shorter left leg has a body mass acceleration down onto it off of the longer right leg stance phase of gait. This sagittal (forward) acceleration is met by a longer stride on the right with an abrupt heel strike (in other words, the client is moving faster than normal across the left stance phase so there is abrupt and delayed heel strike on the right because of a step length increase. (again, this is just commentary, had we videoed this client weeks before this, you would have seen these gait pathologies. This video shows him ~70% through a gait corrective phase with us.)

Again, this client has bilateral tibial varum. You can see this as evidence due to the increased calcaneal valgus (ie. rearfoot pronation; look at the achilles valgus presentation).
He increases his arm swing on the Left to help bring the longer Right lower extremity (relative) through.
if you look closely you can also see early right heel departure which is driven by the increased forward momentum of the body off of the short left limb. In other words, the body mass is moving forward faster than normal onto the right limb (because of the abbreviated time spend on the left “short” leg) and thus the forward propulsed body is pulling the right heel up early and the heel is spinning inwards creating a net external rotation on the right limb (look for the right foot to spin outwards/externally ever so slightly in the second half of the video).

Early heel departure means early mid and forefoot weight bearing challenges and thus reduced time to cope well with pronation challenges. As we see in this case where the right foot is pronating more heavily than the left. You can think of it this way as well, the brain will try to make a shorter leg longer by supinating the foot to raise the arch, and the longer leg will try to shorten by creating more arch collapse/pronation.