Not another Cross over runner ! Yup, and some new pearls on the topic.

Watch this video (and we will post her second video shot from the side in a separate blog post) so you can see some of the components we will talk about today.

Quite often in the Cross over gait the runner has great difficulty getting into the glutes (max and medius) effectively.

In this video today from Runblogger, we see yet another runner who is lacking skill and strength in the appropriate muscles and patterns to run efficiently.

  1. In this video it is clear that she has the classic Cross-Over stride flaw. This video is nice because there is a line present to support our cause, the feet at basically falling on a line instead of below the hips. We see the typical far lateral foot strike in this runner that is classic for Crossing over.  This more lateral strike, even though it is a nice midfoot strike (see the side video shot in the other video of her we post), causes pronation to occur quicker and longer than normal and can create an abductory twist when the heel departs from the ground. However, we do not see the abductory twist like we saw in the Lauren Fleshman videos.  Why not ? because this runner has the foot progression angle at zero, perhaps negative 5 degrees (what we are saying is that she is toe’d-in). This is appears to be from her having mild internal tibial torsion. And a negative foot progression angle will help hold the arch through pronation and in this case is protecting from the abductory twist of the foot at heel rise. There is most likely a forefoot varus here as well (note the inversion at strike). Most likely it is functional; she appears to have inadequate motion in the rear and midfoot, so the pronation must occur somewhere and we see it here in the forefoot.

 Pretty cool to see how a subtle change in one’s anatomy can play out differently.  Go back and watch the Fleshman video blog of weeks ago and watch for the abductory twist of the feet.

2. In this runner, what we really wanted to discuss however is the poor motor control of the gluteus medius and maximus (maximus will be in #3). We can clearly see in this video that during all phases of stance, the pelvis is dipping on the contralateral side. This downward drop is creating a greater gluteus medius lever arm and thus greater demand on the gluteus medius, and in this case a failed attempt (if the opposite hip were hiked, the lever arm would be reduced and put lesser demand on the gluteus medius, less fatigue factor). New to this concept ? Click here.Think now about the reciprocal pairing with the adductors and you could understand why her adductors are probably shortened as well; the adductor magnus especially, as it has a secondary motion of external rotation, and it is probably being substituted here to help decelerate the internal spin of the lower extremity

As the longer lever pairs with the body weight factor, there is a vertical descent of the body and this must be made up by eccentric control of the gluteus maximus (the option of optimal choice) or it is dumped into the quadriceps and they are expected to cope with the body mass descent by slowing knee flexion.  She appears to be opting for the later, not a good choice.

3. Now switch over to the frontal plane (side) shot of this runner in the other blog post. Can you clearly see that the quadriceps are being asked to control the decent? Look at the vertical oscillations of her body. Look at the amount of knee flexion occuring at impact.  It is clear that the gluteus maximus is not dampening this drop and this can be seen by the amount of hip flexion noted here. We always think of the glutes as extensors but in gait they are huge dampeners of the rate and degree of hip flexion.

This is very inefficient running.  She could be much more effective and faster if she works on these issues.  If she can just pair improved gluteus medius to control the frontal plane pelvis drop, and improve the maximus to control the sagittal drop there would be more energy to move forward and less wasted into overcoming the ground reaction forces (which she is maximizing) as dictated by Newton’s Laws.

are we the only ones seeing this stuff ?  hopefully you are starting to get real good at this stuff. 

The Gait Guys, saving one runners life (and hips and knees) one day at a time.

Shawn and Ivo