The Basics of a Prosthetic Leg

Jacky Hunt-Broersma is an amputee who’s been running for five years — here are her tried-and-true tips.

It’s amazing how many things you need to think of as a runner to prepare for a race. You train for months, many hours a day (and night): walking, running, building a strong core, and boosting your mental strength. You need to ensure that your fueling, hydration, clothing, and shoes all work for you. And then you have the occasional blisters and the chafing to deal with.

To make things a bit more interesting, let’s throw in a prosthetic leg. Now you need to think of a whole bunch of other things to keep you going, and unfortunately there isn’t a lot of information available for amputee runners.

The reason? There aren’t many people running, especially long distances, on a leg made of carbon.

From the outside, a prosthetic blade looks cool and fast. It looks like you can bounce across the rocks like a fairy without feeling a thing, no blisters or sprained ankles to deal with, and your foot doesn’t get wet when you run through water. And while some of these things are true, it is, unfortunately, not that easy.

I have been an amputee for 19 years and a runner for five years. I lost my leg to cancer at the age of 26, and nothing prepared me for a dramatic experience like that. Learning to walk again on a prosthetic leg—something that your brain doesn’t trust—is hard; it’s challenging to put your faith into a mechanical device that doesn’t give you any feedback about the position of your foot and whether it’s in a safe position so that you can move forward. I never thought of these movements until the amputation, and this was the most difficult thing for me to learn.

I wasn’t a runner before my amputation, but my husband is a runner; when I was waiting for him at the finish line of a race cheering on runners, I admired them all crossing the finish line—they were totally exhausted, but feeling so proud of their accomplishment. It was at that moment that I decided that I wanted to give running a go, but I never knew how complicated the process would be as an amputee.

It isn’t as simple as putting on a pair of running shoes, stepping out the door, and going for a run when you are an amputee. I started running with a walking prosthetic leg, but it was too heavy. I needed something that was made for running, but I first had to do research to find the foot that worked for me.

I had to get my leg measured countless times, and run in a test socket for a while, to make sure the socket fit properly. Then, when I got my new running blade, it took some time to adjust. Yes, the first time I ran with a blade it made me feel like I was flying when compared to my previous leg, but I wasn’t putting all my weight on it. My brain wasn’t connecting the dots yet. I suddenly had this foreign object strapped to my leg, and I was expected to run fast on it. It was a process to build trust, and the more I started trusting the blade, the more weight I could put on it and make my gait much better.

Over the years I’ve learned a lot—here are my tried-and-true tips to not only help other amputees, but to help give able-bodied runners a little insight into what amputees need to think of.

The Basics of a Prosthetic Leg

To understand amputee runners better, it’s important to know the basics of what a prosthetic leg consists of. First, you have the foot, which can also be a blade (that you see runners wear during the Paralympics). The second part is the socket, and the third part is the liner. All three form a prosthetic leg.

Your stump (or residual limb) is the part of your leg where the amputation happened, and this will need to be connected to the prosthetic leg. It works like this: The liner slides tightly over your stump, which in turn slides into the socket (which is molded around your stump) and the socket is connected to the foot or blade.

There are different ways to connect the liner to the socket. For walking, I use a pin socket, which means there is a pin built into the liner which slides or clicks into the socket. For running I use suction—suction sockets are molded around your leg, and the liner and socket fits very tight into each other. The air gets pushed out at the bottom of the socket through a valve. You also get a vacuum system, which consists of a liner that goes over your socket and your leg, and it creates a vacuum to keep your leg in the socket.

More on Sockets

This is a super important piece of equipment, and it needs to fit properly otherwise you won’t be able to go very far. Most amputees will use the same system (pin, suction, vacuum) for both running and walking. However, I found that the pin socket is great for walking—and it is easy to take on and off at night if I need to go to the bathroom—but I didn’t like it for running. It causes too much pistoning (when your leg moves up and down in the socket)—it feels like a shoe that is too big and your foot moves around in it, and the rubbing will cause blisters. The suction system works great for running, and I’ve found this system holds me tightly into place. Out of all the systems, this one gave me the least amount of sweating issues.

The vacuum system is another popular choice, especially for runners. My issue with this system is that you need a long sleeve over your leg and socket. I just found it hard to roll up, and it fits really tight around my knee so I didn’t have a great range of motion. (And the sweating with this system is ridiculous!) I know this works well for some runners, but with the amount of running I do, I’ve found that I had to stop every five miles to dry my leg to prevent it from sliding off, especially when you live in a place with high humidity.

More on Running Feet

There are a lot of options regarding running feet, and I’ve tried a few. Every person is different and will have a different fit, so it’s ultimately a personal choice. The biggest challenge with running feet are that they are expensive, and you can’t just try a foot out and decide if you like it or not. It isn’t like shoes that you can ditch if you don’t like them.

As a single leg amputee, I have to ensure that the foot and blade I choose matches the natural pushback I get from my healthy leg, otherwise I will run lopsided. You need to get the balance right. Not enough pushback and it feels like you are running with a brick tied to your leg. Too much pushback and your leg will bounce too high, injuring your hips.

These are the legs I have the most experience with:

  1. Freedom Catapult

I started my running on the Freedom Innovation Catapult foot. This is a great option for those just starting out, and it’s super easy to adjust. Unfortunately, the tread (bottom part that touches the ground) doesn’t last very long on the trails—I had to stick the tread from my running shoes onto the blade if I went on trails or longer runs.

  1. Fillauer Obsidian

I switched to the Fillauer Obsidian when I started trail running because the foot has a split toe and it helps when running over rocks or roots. I feel more balanced in it, and it has great tread. The only thing with the Fillauer foot is that it is a little tricky to set up, and you will definitely need a professional to help you with this in the beginning.

  1. Fillauer AllPro

I use this as my walking foot. You could also use this as a running foot if you wanted to. I use this foot to power hike, which is part of my training for ultramarathons.

  1. Ossur Flex Run With Nike Sole

This foot seems to be a popular choice among amputee athletes. It comes with great tread, and the Ossur brand has been around for a long time, so it’s a trusted brand. I did test out this foot, and I found it heavier than the Fillauer Obsidian—it just didn’t move with me as well as the Fillauer foot did.

More on Liners

Like the socket, it’s super important that you get a liner that works for you. For my running, I use the Ossur Iceross Seal-In, and for my walking socket I use the Otto Bock Skinguard. The downside with the walking liner is that it doesn’t last very long—I have to replace mine every six months. They aren’t cheap (around $550), and there’s no guarantee your insurance will cover it. (However, you may be able to find cheaper liners through Adaptive Direct or eBay.)

What Is the Cost of Running Blades?

Running prosthetics are expensive, and not all insurance companies will cover it. Prosthetics can cost anywhere from $10,000 and up. There are other options though: There are a few great charities out there that will help with running blades and financing.

How Do You Handle Sweat?

Sweating is a huge issue when it comes to wearing prosthetic walking or running legs. There is nothing scarier (except a snake!) like being out on a run and your leg slides off from all the sweat. One system can cause more sweating than another, so you need to weigh the pros and cons. With my pin and sucking systems, I’ve found that I don’t sweat as much as I do when I used the vacuum system, but sweating is still an issue.

Personally, wearing a sweat sock under my liner has made a huge difference. The one I use is the Knit-Rite Liner-Liner Prosthetic Sock With X-Static—this sock super soft on my skin, and it’s thin enough not to interfere with the tight-fitting socket. The downside with the sock is that it doesn’t last very long, and they are expensive.

Other options to try is to rub your stump full of heavy-duty antiperspirant in the evening before you go to bed. I’ve tried this, and it helped with the sweating, but the deodorant irritated my skin. I know some amputees who have had Botox injections into their stump as well.

How Do You Handle Rubbing, Chafing, and Blisters?

When I first started running with a blade, the socket would rub on parts of my bone and it would be seriously annoying and painful. Rubbing some lube—I use Squirrel’s Nut Butter— on those spots help. (You can also talk with your prosthetist if you’re having this issue, and they can make a new socket that’s wider to relieve the pressure.)

When it comes to blisters, I don’t only get them on my foot, but also on my stump. The trick with blisters is to make sure your skin isn’t rubbing too much and that it isn’t wet, which is a challenge when you are an amputee. Again, if you lube the sections that are prone to blisters, that will help. Also make sure your socket fits properly—but as with feet, your stump will swell when it gets hot and shrink when it is cold. It is very tricky to get something that always fits perfectly.