Last July, I contributed an article to the Swim Brief postulating why Warm Cities, produce Fast Swimmers. My first point was:
"Hands and Feet
I'm shocked at the amount of people in California who wear sandals or no shoes at all, all the time!
In Ohio, and I'm guessing most of the Midwest, people wear shoes all the time! When I say all the time, I mean every waking second, until they go to bed.
Reference:
"Hands and Feet
I'm shocked at the amount of people in California who wear sandals or no shoes at all, all the time!
I repeatedly have to remind kids to bring real shoes to dry-land. One particular kid sleeps in a hammock, so I guess I shouldn't expect anything else.
In Ohio, and I'm guessing most of the Midwest, people wear shoes all the time! When I say all the time, I mean every waking second, until they go to bed.
Even in bed many Midwesterners, like myself, wear socks (I'm trying to knock the habit). This desensitization doesn't only happen in the feet, but also in the hands. During cold spells, gloves help keep the body warm, but also desensitize oneself to sensation.
The cortex is complicated, which neither I, nor anyone else fully understands. However, literature suggests repeated use of an area increases cortex size and firing. Therefore, desensitization (gloves, socks, and shoes) may decrease their cortical size. Moreover, the hands and feet are highly innervated structures. This makes sense, as cave men/women we needed sensitive feet to prevent stepping on rocks and our society still uses their hands excessively making this neural structure necessary.
Unfortunately, desensitization is devastating for feel in the water. Often times, feel is only discussed for the hands, but the feet also feel. In California (and I'd imagine other warm states), the lack of shoes and gloves increases sensitivity and use of these areas, theoretically increasing the cortical demand and size, improving feel (Mullen 2012)."
Upon reflection, I thought of another benefit of not wearing shoes must be discussed: the flattening of feet.
This thought lead me to ... PubMed, time for some research.
Upon reflection, I found an interesting study by Rao (1992) concluding:
"Flat foot was most common in children who wore closed-toe shoes, less common in those who wore sandals or slippers, and least in the unshod. Our findings suggest that shoe-wearing in early childhood is detrimental to the development of a normal longitudinal arch (Rao 1992)".Well this study certainly did not support my theory.
Once again, this caused me to reflect, if wearing a shoe increases flat feet, then why do I feel those who don't wear shoes are superior swimmers...
Another thought crossed my mind, after reading the Rao study, perhaps not wearing shoes increases the strength of the foot muscles, increasing their ability to "grab" and "feel" water with their feet. Rao et al. did theorize the lack of flat feet in those who didn't wear shoes was due to increased foot strength. Once again, this is purely speculative, but if a swimmer obtains greater sensitization and strength of the foot musculature at the feet, they likely can move more water with the feet.
In swimming, the role of the kick can be debated, but the importance of being able to push backwards with the feet is not. Even if you feel the feet are negligible for propulsion (Rushall 2011), it is still necessary to move water with the feet to balance the perturbations of the body caused by the arms and body.
Now, I haven't proved that a flat foot isn't more beneficial for swimming, as it may increase the surface area to push water backwards, but this review did support the notion of increasing overall foot strength is ideal for swimming propulsion. However, much more research is necessary before mandates are warranted.
The cortex is complicated, which neither I, nor anyone else fully understands. However, literature suggests repeated use of an area increases cortex size and firing. Therefore, desensitization (gloves, socks, and shoes) may decrease their cortical size. Moreover, the hands and feet are highly innervated structures. This makes sense, as cave men/women we needed sensitive feet to prevent stepping on rocks and our society still uses their hands excessively making this neural structure necessary.
Unfortunately, desensitization is devastating for feel in the water. Often times, feel is only discussed for the hands, but the feet also feel. In California (and I'd imagine other warm states), the lack of shoes and gloves increases sensitivity and use of these areas, theoretically increasing the cortical demand and size, improving feel (Mullen 2012)."
Upon reflection, I thought of another benefit of not wearing shoes must be discussed: the flattening of feet.
This thought lead me to ... PubMed, time for some research.
Upon reflection, I found an interesting study by Rao (1992) concluding:
"Flat foot was most common in children who wore closed-toe shoes, less common in those who wore sandals or slippers, and least in the unshod. Our findings suggest that shoe-wearing in early childhood is detrimental to the development of a normal longitudinal arch (Rao 1992)".Well this study certainly did not support my theory.
Once again, this caused me to reflect, if wearing a shoe increases flat feet, then why do I feel those who don't wear shoes are superior swimmers...
Another thought crossed my mind, after reading the Rao study, perhaps not wearing shoes increases the strength of the foot muscles, increasing their ability to "grab" and "feel" water with their feet. Rao et al. did theorize the lack of flat feet in those who didn't wear shoes was due to increased foot strength. Once again, this is purely speculative, but if a swimmer obtains greater sensitization and strength of the foot musculature at the feet, they likely can move more water with the feet.
In swimming, the role of the kick can be debated, but the importance of being able to push backwards with the feet is not. Even if you feel the feet are negligible for propulsion (Rushall 2011), it is still necessary to move water with the feet to balance the perturbations of the body caused by the arms and body.
Now, I haven't proved that a flat foot isn't more beneficial for swimming, as it may increase the surface area to push water backwards, but this review did support the notion of increasing overall foot strength is ideal for swimming propulsion. However, much more research is necessary before mandates are warranted.
Reference:
- Rao UB, Joseph B. The influence of footwear on the prevalence of flat foot. A survey of 2300 children. J Bone Joint Surg Br. 1992 Jul;74(4):525-7.
- Rushall, B. S. Swimming Pedagogy and a Curriculum for Stroke Development. 2nd ed. Spring Valley: Sports Science Associates, 2011.
G. John Mullen received his Doctorate in Physical Therapy from the University of Southern California and a Bachelor of Science of Health from Purdue University. He is the founder of the Center of Optimal Restoration, head strength coach at Santa Clara Swim Club, creator of the Swimmer's Shoulder System, and chief editor of the Swimming Science Research Review.











