16Mar ArmaSkin liner socks: a trifecta for happy feet.
ArmaSkin liner socks:  a trifecta for happy feet.

A single application that provides relief against blisters, swollen feet and plantar fasciitis

The foot battleground:

Hikers and runners can give their feet a belting.  The internals of the foot stretch and flex to recover and protect themselves. 

Each foot engages around 1200 times in a kilometre and each strike is at the equivalent of nearly 2 body weights (BW) (1) assailing solid ground via the shoe sole!  This is described graphically for different speeds in m/sec, with the heel strike load being slightly above the propelling front foot load.

body weight impact

Those forces compress and stretch the soft tissues of the foot with potentially damaging consequences. The top soft tissue effects are swelling, blisters and plantar fasciitis.

Blisters:

If the external forces are transferred to the layers of skin, they can become shear forces between skin layers.  With repeated and extended shearing the skin layers can separate and the healing fluid that moves into the rupture is visually identified as a blister.

As described in a recent Runners World UK article ArmaSkin liner socks provide the most promising answer for blister prevention because of its unique friction profile where the inner surface has 3 times more grip than its external surface.  Consequently, much of the external movement takes place between the liner sock and the outer sock leaving the internal skin layers unstressed.

A more detailed review of ArmaSkin blister prevention is covered in an earlier Blog.

Plantar fasciitis:

When walking naturally each foot strike applies 0.2 body weight (BW) equivalent force along the foot, i.e. between the ball of the foot and the heel.

This longitudinal load is largely absorbed by the plantar fascia (3).  Shown in the image this fibrous web is what prevents the arch of the foot from collapsing. It is typically about 3.5mm thick.

plantar fascia

During each stride's contact with the ground, under the 0.2 BW load, the plantar fascia first stretches and then contracts.

longitudinal foot strike load

Increasing speed from 5kph (1.4m/sec) to 10kph (2.8m/sec) increases that up to 0.3 BW.   For runners approaching 16-18kph the plantar fascia is stretched with the equivalent of up to 0.4 BW! 

 

anterior posterior loads

In addition, it has been calculated (2) that a 9-degree gradient, either uphill or downhill increases the force by 75%!

Thus, the fatigue through overuse of this fibrous band of tissue is not surprising.

There are many preventative steps that can be undertaken to limit the damage.  These include pre-event calf stretches and tailored cushioning and support from the shoe and inner sole.  This may include orthotics.

There are in addition a range of Plantar compression socks. The basic benefit of these socks is to provide a tight ring grip around the mid foot.

While not designed with Plantar Fasciitis in mind the ArmaSkin liner sock delivers an equivalent characteristic.  Its tight-fitting polyester provides a snug envelope around the entire foot.

Importantly it should be noted that such socks are also worn during recovery periods.

Swelling:

When you remove your shoes, and your feet and ankles look swollen, it is not necessarily a sign of a problem. For most runners and hikers, swelling is short term and does not typically lead to long-term problems or injury,” says Paul Langer, DPM, a podiatrist in Edina, MN, and expert for Superfeet.

As the body’s natural response under exertion and stress, swelling may not be harmful.  However, swelling can cause discomfort. A swollen foot can find new and damaging contact points within a shoe facilitating blister creation and in any case tightness can be uncomfortable.

There are a number of causes for swollen feet. Here are the three main ones.

1. Muscle and venous expansion.

Whenever you find yourself sucking in extra air it is because your muscles are needing more Oxygen. Whether you are exercising or not, the oxygen in your body is used to break down glucose, creating fuel (4) for your muscles.  This fuel molecule is the source of energy that keeps your entire body going.

To get that oxygen to your muscles, blood flow increases and as a result the volume of muscles temporarily expands.

2. Microtears

With intense workouts microtears occur in muscles. Same goes for valves in the venous system. It’s called venous insufficiency: “The repetitious impact of running causes microtraumas to the small capillaries that deliver oxygen to our extremities, resulting in fluid accumulation and swelling,” says Langer.

3. Your hydration strategy can also affect your feet.

This has to do with the balance of electrolytes and water in your body. “Muscles need sodium to fire properly,” explains Dr. Nelya Lobkova, DPM NYC Podiatrist. “And when the sodium is pulled from our blood to help the muscle contract, water follows.” If the balance of electrolytes to water is off, too much water can enter your cells, causing swollen feet. Therefore, it’s important to maintain your electrolyte levels, especially on longer runs.

 

To compensate for swelling, hikers and runners alike err on a larger shoe sizing to accommodate swelling rather than risk the foot rubbing unnecessarily against the inside of the shoe.   And mid hike or run it is easy to loosen off laces a little to cope with swelling. With clever lacing you can still maintain good tension around the ankle for support while releasing tightness on the rest of the foot.

Wearing compression socks can decrease swelling while exercising and can assist in recovery times by encouraging fluid to move away from lower extremities.  In the case of hikers, a simpler on-trail remedy is to elevate feet during breaks. We covered this in an earlier blog.

ArmaSkin has the characteristics of a compression sock.  Its tight all-over fit helps reduce the amount of fluid accumulating in the feet thus reducing swelling.

Conclusion:

So, the benefits of wearing ArmaSkin liner socks is growing beyond a high level of blister prevention. Its characteristics provide relief for blisters, swelling and plantar fasciitis. A sock that delivers happier feet for hikers and runners!

With this additional information in mind ArmaSkin would welcome feedback from our community of wearers on the topics described above via our CONTACT US.

ArmaSkin liner sock logo

References:

(1) Race Walking Ground Reaction Forces at Increasing Speeds: A Comparison with Walking and Running Gaspare Pavei , Dario Cazzola , Antonio La Torre and Alberto E. Minetti

(2) Ground reaction forces during downhill and uphill running. Authors Jinger S.Gottschall Rodger Kram.

(3) The plantar fascia is a thick band of fibrous tissue that runs along the bottom of the foot between the toes and heel. If the fascia becomes inflamed, it can cause painful feet which can be debilitating. 

(4) https://www.solescience.ca/compression-socks-plantar-fasciitis/

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