Like almost everyone in the western world, I grew up wearing socks with shoes. No questions asked, socks it was. No matter if they were dress shoes, sneakers, running shoes, cycling shoes, or boots, everything but sandals deserved socks.
A good friend of mine from Illinois is doing his Masters design project on shoes, and since I’m an unreformed shoe geek, he asked for my feedback on his post, Why We Should Think About Redesigning Shoes.
We discussed shoe design, shoe fitting, shoe materials, shoe stack height, shoe etc. But all the focus on shoes in our conversation and in the minimalist running trends neglect to recognize that there are two things, in fact, on most of our feet when running: shoes and socks.
As far as running biomechanics are concerned, much attention as already been paid to shoe construction, so I want to poke on the subtle assumption in the running shoe industry that socks are doing their job just fine.
My biomechanical issue with socks
My hypothesis is that socks are inhibitive of natural running mechanics because they isolate the foot from the friction.
It’s not that socks are all bad. They do provide 3 main functions to feet: friction mitigation, thermal comfort, and cleanliness. I appreciate these benefits, but lately the benefits of these has been overshadowed by the inability to feel the shoes I’m running in because of the socks.
Solid foot contact with the ground is a prerequisite to setting the foundation for good biomechanics. Solid contact is can be consider a proxy for achieving a food tripod, where the heal and heads of the 1st and 5th metatarsal phalangeal joints (MPJs) simultaneously engage the ground the provide balance and shift from the initial pronation at contact, to the transition toward supination, and finally to toe-off. Removing one of these points of contact, such as the case with a functional hallux limitus, bad things happen according to the Gait Guys,
…This roll and glide in descending the metatarsal head to the ground is what we refer to as “medial tripod anchoring”. Disruption of this roll and glide at these joint surfaces through this extension movement to get the metatarsal head to the ground… Failure of this biomechanical mechanism leads to insufficient medial tripod, aberrant toe off mechanics, probably pain, and risk for bunion and hallux valgus formation (because when the medial tripod is not anchored the functional mechanics of the adductor hallucis muscle changes and ends up pulling the hallux laterally).
It’s a bit of a stretch to say wearing socks is the same as a functional hallux limitus, but just go with me on the broader idea that poor tripod means sub-par foot function. Does wearing socks actually keep the foot from anchoring to the shoe though?
According to researchers at the Hong Kong Polytechnic University in a 2005 paper, shear force between the foot and footwear is greatly reduced by wearing socks of low friction coefficient against the outsole. My hypothesis is that this reduction in friction induces the proprioceptive confusion and inability to anchor the foot to the shoe as it would anchor to the ground without the shoe and sock. This is, I believe, the root of my proprioceptive dissatisfaction with wearing socks while running.
Back to the conversation with Ehsan, I started thinking about how to recreate barefoot experience if shoes are still required, and my first solution was going sockless. In fact, over the last month, I’ve converted to running nearly all of my runs sockless in Saucony Kinvaras, Salomon Sense, and track spikes. All of these shoes happen to be designed for sockless running.
But, a shoe without a sock is an imperfect system, mainly because of the requirement of friction to hold one’s foot in the shoe and the tendency of the foot to sweat. The result for me is a dusty, squeaky heal, especially on longer runs.
So, my experimental solution is a half-sock that cover the ankle, heal, and rear half of the arch, which protects the ankle and prevents squeaking where the heal cup contacts the foot. Below is a highly-technical drawing of the concept.
The critical feature of this design is that it does not cover the toes and MPJs, thereby enabling a respectable medial tripod anchoring assuming loss of friction due to socks in the heal is negligible compared to the losses in the forefoot. However, if this assumption is found to be invalid, an oval of below the heal could be removed, similar to the hole in the rear of the Nike Zoom Victory track spike:
In my research, I’ve only been able to find half socks called clog or slide socks that cover the front half of the foot, as well as a plantar fasciitis sleeve make by Feetures that covers the back half and the MPJ’s. I’m on a mission to find a half sock that fits the requirements above or sew up my own pair when I get back to Illinois over Christmas vacation.
Maybe these will resolve my biomechanical issue with socks.
Bonus, shot of the week.