The Gray Institute calls the foot/ankle the "switch that turns on the engine." Or in other words if your foot is not functioning optimally then movement at the knee, hip, back, and on up will be compromised, and long term may cause dysfunction.
Without proper talus (ankle) function torque cannot be converted into power in the lower body. Or in other words if your ankle is messed up it will affect how you walk or run. Common sense right?
Then think about how that may affect your fitness training. If you are running on shoes that are worn out or unstable, or if you train in the gym and in poor footwear, at the very least you are compromising progress. At worst you are causing injury to yourself. For those with flat feet or high arches, wearing the wrong shoes will hinder conversion of torque into power at the hip, which ultimately means compromising strength at the very important hip joint.
But aside from shoes if the ankle and foot is not able to function well in all degrees of motion, lacks stability, or if there is excessive fascial tension then ground reaction forces will not transfer properly into movement. For example if one's ankles do not dorsiflex or evert properly then restrictions there mean there will be increased stress on the knee in order to produce movement. Over time this may lead to knee pain and possibly injury.
But as physical therapist Bill Hartman points out here issues may not be only physiologic but neurologic. In other words long term ankle stiffness may lead to neurologic adaptations that negatively affect movement quality even after stretching the ankle. Other areas have been taking up the slack for the ankle and must now be retrained along with the ankle in order to produce good movement.
Let me explain with a little demonstration.Take your shoes off and stand up…I’ll wait.Now, keep your knees straight, stay tall, and slowly lean forward until the moment you feel like your heels will come up off the floor and hold that position. Do you feel it?Do you feel your toes grip the floor? Do you feel the tension move up into your calves?In an effort to maintain stability, your nervous system turns on your calves and the deep posterior compartment musculature and on up the kinetic chain. Many athletes have the exact same problem.Your mobilization and stretching may have addressed the physiologic stiffness that would prevent normal ankle mobility, but if your athlete has poor control of his center of gravity, the stiffness will persist to maintain stability. The result is a neurologic barrier to performance and greater risk of injury.Got an athlete with plantar fasciitis, anterior knee pain, groin pain, piriformis syndrome?Consider looking at the factors that influence center of gravity and the associated alignment and muscular activation patterns.Here’s a hint…start from the ground up.
Check out this video of Lenny talking about functional and structural work.
The final take home point is this. I see many people in the gym wearing shoes that appear to hinder their training. Take the time to find a great pair of shoes, or go barefoot if that is appropriate. If you are not sure what type of foot you have - flat, normal arch etc... than find someone qualified to help you. Doing so now may save you a lot of pain and money down the road. Same as eating well.
Funny how everything is connected isn't it?