Obligate Pathomechanics

Much of what we see in gait analysis is secondary to the anatomical and physiological constraints exhibited by a patient. Take a look at this gentleman running. At first glance, you may be saying “yup, crossover gait, strengthen the gluteus medius complex“.

Now let’s talk about his physical exam. He has “windswept biomechanics“, With external tibial torsion on the right and internal table torsion on the left. There is no significant difference or increase in his Q angles bilaterally. He has a forefoot supinatus on the right side (I.e his forefoot is inverted with respect to his rear foot). He has limited plantar flexion of the first Ray complex on the right.

Now watch the video again with this in mind. Can you understand that if he’s unable to get his first ray to the ground he’s going to have any sort of hike your push off, in order to get it to the Ground he’ll need to mediately rotate his lower extremity and increase the valgus angle on that side. External tibial torsion (when you drop a plum line from the tibial tuberosity, it passes medial to a line passing to the long axis of the second metatarsal) compounds this. Stand up, rotate your right foot to the outside, keep it there and walk forward. Do you see how your knee has to go to the inside to push off your big toe?

Yes, he has a crossover gait but it is obligate and a direct function of his inability to descend the first ray, at least partly due to his forefoot supinatus and his external tibial torsion on the right.

Obligate pathomechanics. Coming to a patient in your office or one of the folks you are coaching soon.

We will be talking about foot types and pathomechanics tonite, October 16th, 2019, on our 3rd Wednesday’s teleseminar on onlinece.com: Biomechanics 314

5 pacific, 6 mountain, 7 central, 8 eastern

Dr Ivo Waerlop, one of The Gait Guys

This simple screening test becomes a form of exercise.

Today we look at a simple CNS screen for your “central pattern generators” or “CPG’s”. If you do not pass, then the exercise becomes the rehab exercise. If you (or your client) does not have good coordination between the upper and lower extremity, then they will not be that efficient, physiologically or metabolically. 

The “cross crawl” or “step test” looks at upper and lower extremity coordination, rather than muscular strength. If performed for a few minutes, it becomes a test that can look at endurance as well. 

It is based on the “crossed extensor” response, we looked at last week. That is, when one lower limb flexes, the other extends; the contralateral upper limb also flexes and the ipsilateral upper limb extends. It mimics the way things should move when walking or running. 
 

• Stand (or have your client stand) in a place where you will not run into anything.
• Begin marching in place.
• Observe for a few seconds. When you (or your client) are flexing the right thigh, the left arm should flex as well; then the left thigh and right arm. Are your (their) arms moving? Are they coordinated with the lower extremity?
• What happens after a few minutes? Is motion good at 1st and then breaks down?
• Now speed up. What happens? Is the movement smooth and coordinated? Choppy? Discoordinated?
• now slow back down and try it with your (their) eyes closed

If  movement is smooth and coordinated, you (they) pass

If movement is choppy or discoordinated, there can be many causes, from simple (muscle not firing, injury) to complex (physical or physiological lesion in the CNS).

• If movement is not smooth and coordinated, try doing the exercise for a few minutes a day. You can even start sitting down, if you (they) cannot perform it standing. If it improves, great; you were able to help “reprogram” the system. If not, then you (they) should seek out a qualified individual for some assistance and to get to the root of the problem.

Training out a crossover gait?

This gal came to see us with right-sided hamstring insertional pain. During gait analysis we noted that she has a crossover gait as seen in the first two sections of this video. In addition to making other changes both biomechanically (manipulation, gluteus medius exercises) and in her running style (“Rounding out her gait” and making her gait more “circular”, running with less impact on foot strike, extending her toes slightly in her shoes) she was told to run with her arms at her sides rather than across her body. You can see the results and the third part of this.

Because of her bilateral gluteus medius weakness that is seen with the dipping and lateral shift of the pelvis on the footstrike side, she moves her arms across her body to move her center of gravity over her feet.

Yes, there is much more work that needs to be done. This is one simple step in the entire process.

Can you see it?

Here we are again. We have looked at this picture before; once about head tilt, and another about flip flops and form.

Take a good look at this picture and what is different about the child in blue all the way to the right and all the others with the exception of the boy in pink, that we really cannot see?

Can you see it? No, we don’t mean the flip flops (but if you caught that all the boys were in sneakers and all the girls are in flip flops, you are good!)

How about looking at arm swing? Remember this post on arm swing and crossover gait, with the simple cue for correction? All of the children EXCEPT the boy in blue, are drawing their arms ACROSS their body (ie: flexion, internal rotation and adduction). Take a look at their legs. Yep, crossover gait (flexion, internal rotation and adduction). Little boy blues arms are going relatively straight and going in the saggital plane, where the others are going in the coronal plane.

We are not saying that blue does not have some gait challenges, like his torso shift to the left (or pelvic drift to the right), most likely do to gluteus medius weakness or inappropriate firing of the gluteus medius on the left stance phase leg; or his head tilt to the right, which most likely represents a compensation for the right pelvic drift and left body lean.

Arm swing. A very important clue to the puzzle we call gait and compensation. It is more prevalent than you think, and, in some cases, easily corrected with a simple cue.

The Gait Guys. Making it real and pertinent, in each and every post.

Take a look at this gal.

Why does she have a cross over gait?

• note how much tibial varum she has (curvature of the tibial in the coronal plane)
• how much adduction of the right foot there is, potentially indicating a tight posterior compartment, or perhaps a loss of internal rotation of the right thigh
• the excessive posterior rotation of the left shoulder and upper body
• the subtle abduction of the right arm compared to the left
• the slight torso lean to the left

The correct answer is we don’t know until we examine her. Maybe is is there out of necessity or perhaps it is a more efficient running style for her. Here are some points:

Technical Issues with the crossover gait

The cross over gait may be:

• a more efficient running style
• a potential pathologic musculoskeletal motor pattern
• better for long distance runners
• a challenge to balance because of a narrower base of support

It may also be related to:

• a weak gluteus medius
• weak adductors
• excessive foot pronation
• lower extremity morpholgy (like tibial varum, forefoot varus)
• a weak vastus medialis
• a weak tibialis posterior
• and the list goes on

Join us, tomorrow, Wednesday evening, 8pm EST, 7 CST, 6 MST, 5PCT for an hour of crossover gait on chirocredit.com or onlinece.com for Biomechanics 316. We look forward to seeing you there..

The Gait Guys: Shawn and Ivo

Classic Crossover Gait Case.

Here is a client with a uncompensated forefoot varus (ie: the forefoot is inverted with respect to the rearfoot) and a cross over gait, secondary to incompetence of the medial tripod of the foot (he cannot descend the head of his 1st metatarsal to form the medial tripod due to the uncompensated forefoot varus) and weak right lower abdominal external obliques which we discovered on examination (perhaps you can detect a subtle  sag of the right side during stance phase on that side).

Note how he circumducts the lower extremities around each other. This takes the cross over to another level and it can occur when a client is pronating through the medial tripod such as in this forefoot varus case (we know this from the examination, it cannot be detected for sure from the video with the foot in the shoe, that would be an assumption).

How do you fix this?

• tripod standing exercises
• core stabilization exercises with attention to the right lower oblique (see our core series available for download on Payloadz here and here
• foot manual therapy to improve motion of the 1st ray
• see our crossover gait series on youtube here: part 1, part 2, and part 3
• form running classes such as Chi Running

The Gait Guys. Bringing you the meat, without the fat.

all material copyright 2012 The Gait Guys/ The Homunculus Group: all rights reserved