The Case of the Apropulsive Cyborg Gait !
Can you identify the deficit in this gait pattern ? Yes, the Cyborg looks like he is pulling his feet out of quicksand with each step, but why ?
Please do not read on until you watch the video a few times……watch the video again and improve your powers of observation and of what you know to be true biomechanically to identify the gait deficit.
This is a recycled blog post from our archives in 2011.
For those in the medical field, you have likely seen this problem……but only unilaterally and that is why it might not be initially familiar. HINT: It could be a lesion of S1 (the first sacral nerve root.)
As I (Dr. Allen) sit at my computer at home I have my desk oriented so that I look out of 4 windows onto a secluded quiet street that many runners in the area have adopted as a safe road to travel. Little do they know what I do for a living let alone that I am spying on them. But, some days I feel like I should hire some high school kid to just hand out my cards at the end of my driveway with an additional little typed up synopsis of their running flaws and list of probable injuries they either currently are milking, or have in the past (or are about to experience !). And so, on my days off I get to work at my desk and look up and see more runners run than I do during a busy day at my clinic. It is both a blessing and a curse. It seems that I just can never get away from this stuff. Heck, I was cooking up dinner the other night and I caught a glimpse of a trailer for a new TV show, and I was hit with seeing yet another interesting gait which prompted yet another call to my partner Ivo. I said to him, “man, you think the celebrity and Gait Guys at the Movies was a neat idea (thanks again Bill !) wait until you hear this idea ! (you will get a sample of that very idea later in the week ! It should be a hit !). Ok, enough babbling. I wanted to create enough dialogue between my initial question so that your wandering eye would not look further down for the gait deficit by curious default.
OK, so what did you see ?
if your answer was……..the Cyborg does not have any ankle plantarflexion whatsoever, you would be right. And without any plantarflexion a person will always be in a forward lean like they are pushing a refrigerator across the floor. Or better yet……like a hockey player who’s skates are laced as such to block out plantarflexion. Plantar flexion, eversion and abduction are all components of pronation; the action which makes the foot a “mobile adapter” rather than the rigid lever of supination we need to propel ourselves forward. This is why they power out the movement to the side and off the inner edge of the blade (in fact, if you look closely at the right ankle of the Cyborg, you will see it flip out into external rotation very quickly just like a NHL pro……by turning out the foot into external rotation he can thus create a push off from the medial foot and big toe, utilizing the FHL to assist in push off.
The left foot (which does not do this), has nothing else to offer.
In this gait, the body mass must lurch forward with an abrupt jerking motion (generated by the rectus abdominus, obliques and hip flexors) and heavy forward arm pump to accelerate the mass forward enough to literally PULL the glued foot off of the ground (PULL rather than PUSH from the gastrocsoleus/gluteal complexes). This would be classified as an APROPULSIVE gait. We have heard some in the coaching world would call this a PULL gait rather than a PUSH gait.
So, I wonder what this cyborg’s foot would look like ? We bet there would be a massive toe long flexor response (and likely hammer toes) in an attempt to find something in the posterior compartment for forward propulsion. Of course this phenomenon would likely not be seen in a broad based S1 nerve root lesion but in a non-ablative non-nerve related problem (ie, a functional problem with the posterior compartment) you could see compensations such as this from the other possible ankle plantarflexor muscles (tibialis posterior, plantaris, flexor digitorum longus).
So, good video case……..hope you enjoyed the case of the Apropulsive Cyborg !
we remain, ……. The Gait Guys……..Shawn and Ivo