Exploring the Links Between Human Movement, Biomechanics & Gait
Shoe News you can use….
Last time we talked about the outsole (see here and here if you missed it or need a review). Today we will focus on the midsole.
The Midsole, sandwiched between the outsole and the upper, provides torsional rigidity to a shoe. They can be single (uni) density (left picture) or multiple (middle picture).
Midsole material is very important, as it will accommodate to the load imposed on it from the person as well as any gear they may be carrying. It serves as the intermediary and transducer for load transfer between the ground and the person.Softer density material in the heel of the shoe, like in the blue lateral side of the shoe in the bottom picture, softens the forces acting at heel strike and is good for impact and shock absorption.
Because the midsole tranduces forces and provides torsional rigidity (picture on right). The stiffer the material, the more motion control it provides. Midsoles like the one in the center are made with materials of differing densities (white is softer, light grey more dense, dark gray, most dense) to absorb force and decrease the velocity of pronation during heel strike and mid stance, with a firmer material medially that protects against overpronation as you come through mid stance and go through toe off.
Wow. Shoe anatomy for the day. Knew this? Great! Lost? Want to know more? Download our Shoe Fit Certification program by clicking here. You can also email us for more information about becoming IFGEC certified in shoe fit: firstname.lastname@example.org
Ivo and Shawn. Bald. Handsome. Knowledgeable. The Gait Guys!
The Vamp: What you need to know… (3 pics here today)
Vamp may refer to anything from a Norwegian folk band, a repeating musical figure in a song, a femme fatale, a vampire, a movie, action figure or comic character. It can also be part of a shoe.
For our intents and purposes, though these are all interesting topics, we are going to limit our discussion to shoes…
Every shoe has an upper part that helps hold the shoe onto the foot. The “vamp” refers to the upper at can cover anywhere on the top part of the foot between where the toes and the legs connect to the foot.
In styles that don’t offer a lot of coverage on top of the foot, the part that covers the tops of the toes might also be referred to as the vamp. Closed footwear, such as boots, trainers and most men’s shoes, will have a more complex upper. This part is often decorated or is made in a certain style to look attractive.
The vamp has a medial and lateral part. The medial vamp (located on the inside or big toe side of the shoe) often gives support to the medial longitudinal arch of the foot (since most shoes offer little if any arch support in and of themselves). Likewise, the lateral vamp can (but often does not) offer support to the lateral longitudinal arch.
Most folks like shoes with a larger, snug medial vamp, because it “feels” better and that’s what they are used to. Then again, most people wear shoes that are too tight for their feet anyway. More on this in a post on the Brannock’s Device.
The Vamp. An athletic supporter for your feet : )
Ivo and Shawn. Definitely Foot geeks, but not shoe vamps.
Shoe Retail Thursday: Today we have a client in some shoes that appear to be a good match, until you look more closely. See if you can see it.
” Just because the shoe fits, doesn’t mean you should wear it ! ”
– The Gait Guys
First of all, we apologize for the crummy video. But we were scouring through some old stuff while working on our long awaited “Shoe Fit” program and this video just had to be shown. This is a short video, you might get some vertigo from the nasty camera work. Sorry about that.
Initially this client looks great from behind. The rear foot looks neutral, no valgus heel collapse into rearfoot pronation and no over burdening of the lateral crash zone (lateral/outside tipping of the shoe into supination). If anything could be said, they look like there could be a subtle rearfoot supination from the initial shot before they start to walk.
We are also not sure what shoe this is, we do however know it is a New Balance stability shoe from the video. This client had purchased these shoes 1-2 weeks prior in a trusted high end specialty running store. As the client walks away from us everything looks pretty good. We could point out some subtleties but those are not the point of our talk today. It is not until they come walking back that something is clearly wrong. Did you see it ? The LEFT foot is drastically supinating displaying a lateral weight bearing shift all the way through toe off.
Now, on the surface this is a simple case. (We just shot a concept video last night to take this blog post today to the next level. We will present it next week once we get it edited.) But the points we need you to understand today are :
Just because someone has a flat foot standing in front of you does not mean they need a stability shoe. We see plenty of folks who are serious walkers, runners all the way up to professional athletes who have flatter, or flattened, medial longitudinal arches but still have very strong competent feet. There are ethnic groupings that have flat feet. So just because a foot looks flat does not mean one should reach for a stability shoe or an orthotic or additional foot bed insert. This client had flatter arches but had competent feet. They also had some issues of tibial torsion that negated some of the challenges of flatter feet. So, our point here is what you see is not always what you get, nor what you should fix either for that matter.
What should happen in a shoe does not always truly happen. This means you have missed some calculations or you simply do not have enough experiential wisdom to predict the oddities in certain situations or with the given anatomy of a given athlete. This comes in time, with experience.
Sometimes supination is not really supination. This client has a flatter foot. Flatter feet do not supinate well. Ok, better put they run out of time to supinate the foot because they have spent too much time into the pronation phase. However, they also could have weakness in the supinatory mechanisms to drive it adequately. Remember, some clients will fall into their weaknesses and some will strategize to avoid the weaknesses if they have enough body awareness and strength to do so. They just do not seem to have the skills to find the more appropriate pattern to correct the underlying issues. But there is certainly something positive to be said to knowing you have a problem and that you are cheating around it rather than being oblivious.
This case was possibly, maybe even likely, one of several problems:
wrong shoe for the foot type
possibly a faulty shoe fabrication
poor strategy to make for a rigid foot structure
This case also draws clinical inquiry into:
whether there is weakness of the ankle and forefoot everting muscles namely the peronei and extensor digitorum longus and brevis. * This the topic of the video we are producing because these muscles have huge implications in the cross over gait (which we have senselessly beat you all with in previous blog posts) at the lower end of the limb.
Who are we ? The Gait Guys…… Shawn and Ivo. The dynamic duo of all things gait.