The human foot is an intricate and dynamic structure designed to support the body’s weight, absorb shock, and facilitate efficient movement. In my opinion, its most important role is to provide sensory information to our brain about the environment when we stand, walk, or run. The foot is complex anatomically and biomechanically. It consists of 26 bones and four layers of muscles collectively known as the intrinsic muscles of the foot.
These muscles, along with the foot’s numerous joints, contain an abundance of sensory receptors including joint mechanoreceptors, Golgi tendon organs, and muscle spindles. These sensors, located within the joint capsules, tendons and muscles, relay environmental information—such as ground texture and density—along with physical information regarding joint position and muscle length to the brain. This sensory input is crucial for the reflexive and automatic control of posture and balance that produces safe and efficient movement.
Our perception and response to the physical environment depends on the quality of sensory information we receive and how efficiently our brain processes it to create our current reality. At its core, this includes visual, vestibular, and proprioceptive input. Proprioception refers to two kinds of bodily sensations – static limb position and the rate of movement – and occurs both consciously and unconsciously (for a more detailed overview of proprioception, click here or here). The muscles and joints of the foot are major contributors to proprioception, helping us maintain both static and dynamic balance, posture, and the ability to perform complex movements required in sports and daily life. Thus, maintaining proprioceptive function is essential for aging gracefully and preserving both physical and neurological health and independence.
When proprioception becomes impaired or diminished, we often see a loss of balance and postural control. This issue manifests on a spectrum. A common example at a far end of the spectrum is seen in those with poor blood glucose regulation, such as those with type 2 diabetes. Chronically elevated blood glucose levels can damage large-diameter sensory neurons, which are responsible for transmitting proprioceptive information to the brain. This is why you may see people with severe diabetes develop poor balance, cuts and injuries to the lower limb more frequently. Not only do they have poor blood supply from co-existing conditions, but they also have reduced ability to feel and reflexively control the position and response of their feet. Less sensory input means less information for our brain to work with, resulting in less accurate motor responses, and therefore potential injury. This is detrimental to both long-term physical and neurological health as it can increase the risk of fall and injury.
What Can We Do to Maintain Foot Health and Proprioceptive Function?
We’ve all heard the saying, "If you don’t use it, you lose it." This holds true for conditions such as osteoporosis and sarcopenia, where a lack of weight-bearing exercise and resistance training leads to declines in bone density and lean muscle mass, respectively. This principle also applies to the brain and nervous system—arguably even more so. Simply put, the brain relies on three things to function well: oxygen from the blood, glucose for fuel, and sensory input. Removing any one of these elements may negatively impact brain health.
Footwear can significantly reduce the sensory input component of this equation. Now, I’m not here to promote scrapping shoes altogether and showing up to work to wiggle your toes in the face of your HR manager, (that would pose multiple problems that you or I are likely not willing to deal with) but I do think we rely far too heavily on ultra-supportive footwear nowadays.
Most of this is due to cultural and social changes. Shoes have been great at permitting us to move more comfortably in places we wouldn’t typically have access to, but really, we weren’t built to be constrained in tight footwear all day. We’ve gradually become less tolerant of harder surfaces and longer durations on our feet, while centuries ago people wouldn’t think twice about walking through the woods barefoot all day to hunt for their next meal. Although we don’t have any data to suggest they remained injury free, it’s safe to say they were likely walking much more than us and obviously relatively successful in doing so.
Prolonged use of tight footwear tends to create problems in the form of pain or injury if we don't select what we wear wisely and/or make time to be barefoot when possible. For instance, high heels or shoes with tight toe boxes can lead to plantar fasciitis, heel pain, forefoot pain, or irritation of nerves between the toes. You may even be thinking right now, "Yup, I’ve dealt with one of those."
Typically, shoes restrict the natural movement of the foot, which is designed to function in three dimensions. The 26 bones and four muscle layers in the foot work synergistically, and when the toe box of the shoe is constricted, it alters normal biomechanics. This restriction prevents our ability to fully splay our toes, invert and evert the hindfoot, and pronate and supinate the midfoot—movements that are necessary for proper foot function and to maximize sensory input from our environment.
If you spend most of your day in heels or shoes with restrictive toe boxes, here are some simple strategies to improve foot, physical and even brain health:
Go barefoot at home. Avoid wearing shoes, slippers, or socks indoors. This can boost proprioceptive input and engage the muscles of the feet for better stability and support.
Use toe spacers. These devices help mobilize the joints between the toes and encourage positions not permitted by tight footwear.
Exercise barefoot (if your gym allows it). Removing shoes during exercise helps your body rely more on the intrinsic stabilizing muscles of the foot. Click here for some examples I've shared on my instagram page.
Perform balance exercises. Practice balancing with your eyes open and closed, on hard floors and soft compliant surfaces. Progressively increase the difficulty as you improve.
Strengthen intrinsic foot muscles. Many people find it difficult to move their toes independently, similar to how we move our hands. Working on this can help develop strength and motor control in the muscles that support the foot, while also providing novel sensory input to the brain.
Walk barefoot in nature (when safe). Walking on grass, sand, or other natural surfaces offers unique sensory feedback to the feet and the brain.
While it’s not feasible to be barefoot all the time, even a small amount of barefoot activity can make a significant difference. The key is to recognize how much you rely on footwear and gradually find ways to implement some barefoot moments during your day. Reintroducing strategies that allow your feet to move naturally will provide novel sensory stimulation to the brain and nervous system that may help develop and maintain control, balance, strength and brain health as you age.
Conclusion
Your feet may seem far from the brain but they are, in fact, some of the most valuable sources of sensory input that help maintain upright posture, balance, and the ability to walk and run. While the feet are not the only factor, they play a crucial role in the longevity and high-performance puzzle and we know that the loss of foot function is closely linked to various metabolic and neurological conditions. Thus, if we consciously maintain foot and proprioceptive health we are also doing work to support brain health. Conversely, preserving our brain health may also enhance proprioceptive function. To live well and perform well, you have to hit it from all directions.
Yours in good health,
Andrew
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