Until recently, putting on a pair of socks was about as important as putting on a pair of underwear. They merely served as a barrier between your feet and your shoes. Socks are no longer just mundane apparel destined to be lost in the dryer. An enormous amount of research has been done on different fibers and fiber blends making socks just as impressive as some of the shoes we now see in the market. Believe it or not choosing the right sock can be critical for your comfort and your health.
Over the past decade, sock technology has evolved to address the main problems athletes face with their feet….sweat. The palms of the hands and soles of the feet have far more sweat glands relative to other parts of the body. Feet sweat about 10 to 15 gallons per foot per year. Having that moisture against the skin significantly increased the coefficient of friction. Having this increase in friction results in an increase in shearing forces which results in blisters. The terms “hydrophilic” and “hydrophobic” are used when discussing sock material. Hydrophilic means the material draws water to the fiber while hydrophobic fiber wicks water through the fiber. While there are socks composed of blends of both types of fibers designed to wick fluid from the skin and absorb the fluid in a layer away from the skin as a general rule athletes should look for hydrophobic material in their socks.
Naturally, with all of the different types of socks and different types of fibers, some people will have different reactions to how they ultimately feel in a pair of socks. Different fabrics have different textures that people may not like due to how it makes their body react. For example, some patients report that socks that are thin and have a silken feel will cause them to be uncomfortable and sweat more. This type of uncomfortable feeling can cause the hands and other parts of the body to sweat. Often times, they look for socks that have more texture, regardless of material, to make them feel comfortable.
The choices in sock materials are laid out below, so when you are looking for your next pair of socks, please consider the options and try to make the most informed choice that works best for you.
COMMON FIBER TYPES USED IN THE MANUFACTURING OF SOCKS
Most people are surprised to discover that cotton is about the worst material you can choose for an athletic sock. Cotton, a nature fiber, is the most widely used fiber for socks because it is inexpensive, cool, and breathable. While it is a great choice for outer apparel, in the closed environment of a shoe it is a poor choice. Cotton fibers are hydrophilic and absorb three times more moisture than some synthetic fibers. Not only that, once wet, cotton retains moisture and has a ten-fold greater drying time. If that’s not bad enough the cotton fibers themselves actually swell when wet which causes them to become compact and lose their shape. This also adds to the likelihood of developing blisters.
Wool is a much better choice for socks than cotton when comparing natural fibers. Wool offers excellent wicking properties and has the ability to absorb up to 33% of its own weight without feeling wet or clammy. Wool also has a natural crimp and resilience due to fact that each wool fiber is made up of millions of coiled springs that provides some elasticity but coil back to their original shape. Wool is a bulkier fiber and allows air to become trapped providing great insulation.
Bamboo has come into favor in recent years as a good natural fiber for socks. Bamboo is breathable and has greater wicking properties than cotton. The bamboo fibers are hollow which makes them more absorbent. Bamboo is also eco-friendly and an evergreen plant which helps cut down on greenhouse gases.
While wool is the best natural fiber available, it doesn’t even come close to beating the synthetic fibers. Synthetic fiber socks significantly outperformed nature fiber socks in four important areas:
Ability to wick fluid away from the skin.
Resist compaction and maintain shape when wet.
Pressure and shear force management.
Synthetic fibers are petroleum based and include: Nylon, Polyester, Polypropylene (Olefin), and Acrylic. Nylon, Polyester, and Polypropylene are forms of plastic that have been extruded through what is essentially a very small spaghetti maker into filaments that are then woven into fiber. While wearing a plastic sock may not sound very “high tech”, keep in mind that billions of dollars’ worth of science and technology have gone into the production of these products.
Nylon in a very strong, versatile fiber. Nylon is often combined with other fibers to give added stretch or to improve durability.
POLYESTER (Terylene, Dacron, Coolmax)
Polyester is the most widely utilized synthetic fiber in the world due to its low cost. It is often used in place of nylon for stretch socks but is not as effective. It has many variants including: Coolmax, Thermax, Thermolite all of which are designed specifically for superior moisture transfer.
Polypropylene is the lightest of the manmade fibers and is very hydrophobic. It is used alone or in dual layer socks as the layer against the skin. An outer layer is composed of a hydrophilic fiber to hold the moisture away from the skin.
Acrylic provides softness and warmth and might be considered the synthetic equivalent of wool. It is often found in wool blends. Acrylic is also a desirable fiber due to its ability to hold brilliant colors.
In reality most socks are a blend of different fibers in an attempt to capture the desired properties of each material. Cotton socks, for example, are great at absorbing moisture but are often blended with Nylon to help move the moisture away from the skin.
Sock liners are made of a thin polyester or wool material that helps wick moisture away from the skin. They are worn under your hiking boots mostly to prevent blistering which can occur when your feet become very sweaty.
Copper is known to have antibacterial properties, and the EPA lists copper as an antimicrobial material. While copper won’t prevent sweaty feet, it will decrease foot odor by decreasing the bacterial count. Copper infused fabric has also been shown to be beneficial in alleviating fungus.
Copper compressive socks are also commonly advertised. They claim the copper will help prevent fatigue and facilitate recovery following injuries. While the compression aspect of these socks is beneficial, there is no scientific evidence showing that copper will prevent fatigue or decrease inflammation.
Sometimes the metal edge that the marketing uses to promote a product, however, will give you the increased push that you were looking for to give you the strong finish that the product claims.
There are also socks available with titanium. Tisoks socks have 3% Titanium woven into the fabric. The titanium releases ions which can help with athlete’s foot. Titanium is reported to have better anti-fungal performance than silver or copper.
Silver has been known for its antimicrobial properties for hundreds of years. Before the discovery of antibiotics silver was commonly used to treat infections. It is still used in everything from food packaging to wound care products. Silver socks are coated with silver nanoparticles which decrease the bacterial count on the feet. Silver won’t help with foot perspiration, but it will help with foot odor that usually comes with foot perspiration.
WHITE SOCKS VS. DARK SOCKS, DOES IT MATTER?
There are many myths about wearing white socks vs dark socks to combat fungal or bacterial infections. From a foot health perspective there is absolutely no difference. The only caveat being that some people may be allergic to certain dyes in colored socks. Also, wearing dark socks with short pants will make you look like a grandpa.
WHAT ARE DIABETIC SOCKS?
Diabetic socks are specially designed socks to reduce the chances of potential foot problems that diabetics are prone to. The two main features of a diabetic sock is that they are non-elastic and seamless. Elastic at the top of the sock can restrict blood flow to the foot or conversely trap fluid in the foot causing swelling. Seams in the sock can create pressure points on the feet resulting in ulcerations. Diabetic socks are also usually more padded to protect bony prominences in the feet.
Compressive socks are beneficial for swelling in the feet or varicose veins. After blood flows down the legs and through the capillaries in the feet it relies on skeletal muscles to literally squeeze the blood back up to the heart. The blood has a long way to travel and it has gravity working against it. With that said, anything we can do to assist the process helps.
Compressive socks are one of these things. Research has shown that wearing compressive socks decreases muscle swelling, decreases pain from “tired legs”, and helps increase lactic acid removal from muscles. Compressive socks can be purchased over the counter at most pharmacies or they can be custom fit by a podiatrist. There are different degrees of compression so consulting with a physician may be advised. Also, it is important to note that there are certain medical conditions where compressive socks are contraindicated.
LET’S TALK TOE SEAMS
Sock toe seams has become a whole science of their own. Socks are manufactured by a machine which knits material into a tube. Another machine then finishes it off by sewing across the tube to close off the toe end of the sock. This can leaves an uncomfortable seam at the toes. The seam creates a bulky ridge that protrude beyond the cushioning of the sock. The seam can drive people crazy if they have sensitive feet. Worse yet, they can cause blistering and ever ulcers in athletes.
Tube socks are the worst. The seam runs across the end of the sock and fall across the tip of the toes. Tube socks are especially uncomfortable with narrow feet because of the excess fabric at each corner creates more bulk from the excess material.
Most socks, besides tube socks, have the seam positioned on top of the toes. Having the seam on top of the toes provides the lease amount of irritation.
TYPES OF TOE SEAMS:
Machine Linked Seam
When the knitted sock comes off the knitting machine it is put in another machine that essentially lays the two ends of the open sock together and sews it shut. This leaves a bulbous raised seam that can irritate sensitive feet. Machine linked seams are what you’ll find when shopping for socks in your run of the mill department store.
Some machine linked seams are “channeled”. Meaning the seam sits behind the yarn loops that provide padding in the sock. Since the seam is recessed in the yarn loops decreasing its bulkiness making it is less detectable.
Hand Linked Seam
With a hand linked toe seam, the two ends of the sock are closed one thread at a time using a single thread. A hand linked seam is also sometimes referred to as a flat seam. The process is labor intensive but results in a very low-profile seam that is almost undetectable. These socks are usually more expensive due to the added labor cost. Hand linked seam socks are often incorrectly advertised as “seamless”.
With flat seams or hand linked seams the seam is almost undetectable and suitable for most people. However, for those who find ever the smallest seam bothersome, there are seamless socks available. To make a truly seamless sock the knitting process starts at the toes and spins upwards forming a tube.