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How a Prosthetic Running Leg Lets You Run An Ultra Marathon

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How a Prosthetic Running Leg Lets You Run An Ultra Marathon How a Prosthetic Running Leg Lets You Run An Ultra Marathon www.runnerclick.com

Runners are programmed to overcome any obstacle in their path, and Amy Palmiero-Winters has the true spirit of a runner. In 1994, she lost her leg after a motorcycle accident. 

With the help of a prosthetic running leg (and years of dedicated training), she currently holds eleven world records and is the first amputee to win an ultramarathon in 2010. 

Amy is proof that you can do anything if you have the drive and determination. 

So, what are running prostheses, and how do they work? 

What are running prosthetics?

When you think of prosthetics, you likely imagine a copy of a leg that is indistinguishable from biological limbs. While these styles of prosthetics help amputee runners navigate through day-to-day tasks, they aren’t exactly ideal for running.

A running prosthetic, also known as running blades, is your best bet in sprinting, when you need to pick up the pace. 

These prosthetics boast a curved design and are made from carbon fiber because it is incredibly lightweight and durable. The original running prosthetic (called the ‘Flex Foot’) was designed by a fellow amputee athlete named Van Phillips in the 1970s. 

Until that point, many prosthetics were designed to mirror the bones in the human body. On the other hand, prosthetist Van Phillips wanted to create something that mimicked tendons and ligaments in the lower leg.

The curved design of the running-specific prostheses works like a spring that helps to naturally propel the runner forward so running amputee sprinters can reach higher speeds with ease.

It’s made to mimic the movement of the calf muscles and Achilles tendon in biological legs for more fluid motions built for speed.

How are running blades made? 

When you move through your gait cycle, you place your body weight on your joints and tendons three times.

The human foot has 26 bones that have evolved to withstand the weight of running to limit the damage to your ligaments and joints. For runners that need a prosthetic, this can prove to be a bit of a challenge. 

Many modern running blades on the market are composed of around 80 layers of carbon fiber to help withstand the continuous weight placed upon the prosthetic. 

Carbon fiber is a perfect choice for running blades because it is stronger than steel but feels lightweight. These blades are strong enough to withstand the impact but light enough to keep your stride nice and bright – even for an ultramarathon!

Since running blades don’t require a shoe, spikes can be placed along the prosthetic base to boost ground contact and traction, similar to the spikes on your running shoes. 

Are They Expensive? 

In short – yes. Even the most affordable running prosthetics will cost around as much as a used car! However, the price tag on these running prosthetics isn’t inflated unnecessarily. There are a few excellent reasons why running prosthetics are so expensive. 

The first reason is that these prosthetics are hand-crafted by a professional. They are composed of up to 80 layers of carbon fiber placed by hand to ensure durability and quality. This process is tedious and time-consuming, hence the high price point. 

It’s also important to note that much research goes into designing prosthetics that mirror a runner’s natural gait cycle. Science is constantly changing and evolving to make new and better designs. 

Prosthetics aren’t just your basic pair of trainers- a team of doctors likely designed custom-made prosthetics for your unique body type. 

Are Prosthetic Legs Fair?

There is a raging debate about the potential unfair advantages that running prosthetics give runners, and it’s a hot debate that likely won’t be settled any time soon. 

While these blades can provide runners with a few advantages, running prosthetics has a few disadvantages. A 2009 study found that there were physiologically similarities and mechanical differences. 

The running blade design provides more energy return than runners that don’t use prosthetics. However, runners will need to excerpt more effort mechanically to achieve the same result as non-amputees. 

Non-prosthetic users rely on the muscles in their legs to build speed and agility, while prosthetic users rely heavily on their hip flexors and core muscles to generate momentum. 

Overall, prosthetic runners’ muscle engagement is radically different from non-prosthetics runners. Is it better or worse? The jury is still out on that one. 

To understand if running blades provide an advantage, we must first understand what makes one runner faster than another runner, and that study is still ongoing!


As time marches on, prosthetic limbs get better and better. The first artificial leg was invented in 1846 by Benjamin Franklin Palmer, and it was designed to help users get from point A to point B. Today, modern prosthetics have come so far that they have made quite a few appearances at the Olympics. 

Modern advancements in prosthetics paired with the relentless spirit prove there is no obstacle that runners can’t conquer. With proper training, prosthetic users can not only compete in ultramarathons, but they have demonstrated that they can also finish first!


  1. Peter G. Weyand, Matthew W. Bundle, Craig P. McGowan, Alena Grabowski, Mary Beth Brown, Rodger Kram, and Hugh Herr, The fastest runner on artificial legs: different limbs, similar function?,

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