by Dr. Brant McCartan
Conventional wisdom has often held that 100% cotton socks are the best for your feet. It is a natural material, so it must be good for you, right? Cotton socks are actually not my favorite. I tend to prefer a blend of acrylic or other natural fibers like wool. What is wrong with cotton? Cotton fibers tend to hold and absorb more heat and moisture. Acrylic is better at wicking – or removing – heat and moisture from your skin. Cotton fibers also tend to get compressed by your foot and shoe. They don’t “bounce back” as well, so the cushioning or shock absorption is not as good.
Why do we wear socks? They help keep our feet warm and dry, and make our shoes much more comfortable by reducing shear, or friction from rubbing. Heat regulation, or keeping our exercising feet cool – is another goal of wearing socks. Socks help in transferring heat from the foot out of the shoe. Many newer socks have very thin upper sock surfaces to promote moisture evaporation and heat release.
The foot sweats a great deal. Coupled with gravity pulling body sweat down towards the feet, the sock gets moist pretty quickly. Increased skin hydration and moist socks result in increased friction and increase the likelihood of blistering. Aside from temperature regulation, studies have been directed at analyzing wicking potential. If certain socks can keep your feet dry, they can therefore prevent blisters.
A study by Herring & Richie found that wearing acrylic fibered socks resulted in fewer and smaller blisters compared to cotton socks. This is likely a result of improved wicking of the acrylic fibers. Acrylic fibers have a higher tensile strength. They maintain their shape and compact less which results in less swelling and better transfer of moisture away from the skin sock interface compared to cotton, which retains moisture ten times greater than acrylic.
Socks can also add padding, good for absorbing the shock from running or walking A good shock absorber releases the kinetic energy transferred from two surfaces over a longer period of time or converts some of the energy to heat. Many studies attribute joint degeneration, osteoarthritis, lower back pain, plantar fasciitis, Achilles tendinitis, metatarsalgia and other aches and pains to poor shock absorption or dissipation. Some authors have shown socks to be beneficial in reducing foot pressures, or shock.
Wearing socks with shoes decreases shear force, or rubbing, significantly compared to wearing a shoe without socks. In a study comparing five different socks: cotton, double layer cotton, wool cushion sole sports, acrylic cushion sole hiking, and toweling cushion sole sports found that only the wool and acrylic socks significantly increased shock attenuation when compared to barefoot walking.
Socks can be an important part of keeping your feet moving without pain. Be sure to bring your preferred socks with you when shopping for new shoes, and to any appointments with your podiatrist. If foot or ankle pain is keeping you sidelined, contact us today.