The subject of running shoes is a pretty hot topic right now and recommending a shoe that’s going to have the desired affect has never been more difficult. Media hype trains, conflicting opinions and a lack of a conclusive body of evidence leave behind pretty murky waters.
This article, and it’s subsequent follow ups, aim to provide some clarity on what we can look for in everyday running shoes.
The best place to start is to stop thinking about neutral and support and to highlight key characteristics of running shoes.
Forget Neutral and Support - Think about Stiffness and Compliance
“Midsole stiffness is the extent to which the midsole resists deformation when a force is applied to it. Compliance is the opposite of stiffness”
A shoe with a compliant midsole is going to compress and easily deform when subjected to external forces. A stiff midsole is going to offer more resistance to forces that attempt to deform it’s structure.
In pretty much every instance, a stiffer midsole is a more stable underfoot platform.
See below for an example of a “neutral” shoe (left) and a “stability” shoe (right). In the video I am deliberately attempting to compress the shoe medially and laterally under my heel. Spot the difference?
If you were to pick up the shoes and attempt to bend/twist them, you would get the same result. There will be greater resistance in the neutral shoe because in this instance, it has a stiffer midsole.
“The relative difference in heel height between the rearfoot and forefoot.”
For example the midsole thickness of the first shoe is 32mm at the rearfoot and 20mm at the forefoot. This gives the shoe a 12mm offset. In other words, there is a pre-existing 12mm heel raise in the shoe.
The midsole thickness of this second shoe is 28mm at the rearfoot and 28mm at the forefoot. There is a 0mm offset in this shoe.
Offsets will almost always range from 0-12mm in running shoes.
This is not as subjective as it sounds
I like to break athletic footwear down into the following controllable variables.
Heel Counter & Collar Depth – Some brands are shallow at 60-70mm and some are deeper at 70-90mm.
See below for a shoe with a shallow heel counter & collar depth. The pen marking shows the collar line of a running shoe with a 90mm (approx) deep heel counter.
Width – Running Shoes come in the following widths. 2A, B, D, 2E, 4E & 6E.
The industry standard is B for women and D for men.
See below for the difference between a 2A width and a 4E width. Both inserts are for a size 9uk.
These are readily available. When recommending a shoe remember you are not limited by a “wide fitting” brand. There is no difference in the price of these when compared to their standard fit counterparts.
Presence of Seams – Some premium shoes have sock-lined uppers. This means the inner layer is seamless. Usually this layer starts at around the same point as where you might tie your laces.
See below example of a sock-lined shoe. The yellow sock liner runs all the way to the distal part of the toe box, inserting into the midsole below the line of the insert.
Presence of Overlays – Some shoes use a medial and lateral midfoot wrap which connects to the laces. When the laces are tightened, this completely secures the midfoot.
See below for an example of an overlay.
Toe Box – They will never come with specific measurements. However some running shoes will present with deeper and/or wider toe boxes than others.
Recommending & Prescribing Shoes
- When recommending footwear try and park the idea of neutral and support. Think stiffness and compliance and how it applies to an individual.
- There is growing support behind recommending footwear on the basis of comfort. Whether right or wrong, know that 9/10 times this advice will lead the service user to choose footwear with a very compliant midsole.
- Remember you can, to a great extent, tailor the characteristics of the footwear to the individuals anatomy. running/walking mechanics and running goals
There are going to be a couple of more posts on running shoes, the next one will revolve around stability shoes and the mechanisms that brands are using within them.