Cycling after amputation
As a prosthetist, one of my favorite things to do is setting up people on their bikes. I run into unique challenges once in a while and it’s very rewarding when all the stars align and things work. One of the most difficult projects I encountered was with a Marine named Rob Jones who sustained bilateral above knee amputations and desired to get back to riding his upright bike. This took about 3 months of trial and error. When he was finally able to get on and off of his bike and ride on his own without assistance, he picked his bike up and held it over his head and we both felt a sense of victory.
Riding a bike is a fun, low impact activity to build leg strength and improve cardiovascular reserve. Hand crank bikes and recumbent bikes are options if riding an upright bike is not for you. Here are a few tips for those desiring to get back in the saddle:
Setting up your bike
A common problem is the prosthetic foot slipping off of the pedal. Clip-in or cage type pedals are a good solution. For safety, when starting out, it’s best to use a flat pedal without clip-ins on the sound side for single leg amputees as you adjust to clipping in with your prosthesis. Clip-in pedals sometimes have a tension adjustment, which allows you to make it easier or more difficult to unclip. Make sure to adjust this setting to the easiest position, meaning the setting with the least amount of tension.
For both above the knee and below the knee amputation levels, the use of a crank arm shortener can help reduce the amount the knee has to bend, which increases efficiency and improves comfort. These allow the pedal to be positioned in a number of different places. You can experiment with various positions until you find which one is best. That means less socket pinch behind the knee or at the front of the hip. Crank arm shorteners are available online or from a local bike shop. It’s important to know the width of your crank arm when ordering.
For those with single arm amputations, both front and rear shifters can be mounted to the sound side handle bar. Brakes can be wired together or a single brake can be used.
Setting up your prosthesis
If possible, start on a stationary bike or trainer to make sure your prosthesis is comfortable and aligned correctly. It’s also possible to simply not use your prosthesis and to pedal only with your sound side.
A common problem is that the heel of the prosthetic foot hits on the crank arm. If this is the case, your prosthetist may be able to show you how to change your alignment when getting on and off the bike. For above the knee sockets, it sometimes works to have your prosthetist cut down the height of an older socket to improve comfort on the seat. A waist belt can help with suspension and rotation control. Certain prosthetic knees allow a free-swing setting which makes pedaling more efficient. It’s important to know how to change this setting when getting on and off of the bike.
For arm amputations, use of the prosthesis is optional. If using an electric hand or hook, be sure to turn it off once lightly gripping the handle bar in such a way that it would come off in a crash but will not come off accidentally.
Your first ride
After you’ve set up your bike and prosthesis, the next step is practicing getting on and off of the bike. It’s a good idea to have someone with you to spot you getting on and off the bike. That person can also help get the prosthetic foot secured to the pedal if you’re having difficulty. Choose a flat surface area with a lot of space and make sure to wear a helmet. It’s best to swing your prosthetic side (or weaker side for bilateral’s) over the bike and secure in the pedal. Getting off requires setting your sound side (or stronger side for bilateral’s) down first. Unclipping the foot requires a twisting motion for clip-in pedals. It is sometimes easier to unclip your prosthesis if you lean your bike over a bit after putting your sound side foot on the ground.
As your cycling improves, you may be looking for ways to bring your sport to the next level. It’s possible for your prosthetist to attach a cleat directly to the carbon foot and to glue tread around it for walking. This lightens up the setup and can make power transferred through the prosthesis to the bike more direct. Special knees are available which make it easier to stand up and pedal.
There are a number of specialized elbows and attachments for non-electric arm prostheses that may improve your experience. Most of these incorporate a release mechanism in case of a crash.
In conclusion, riding a bike with or without a prosthesis may take some work up front to get everything working properly. Once set up properly, it can lead to miles and miles of fun. For Rob, I thought that the moment when he raised his bike above his head was the end of his journey, but it was just the beginning. In 2013, he went on to ride that bike across the entire U.S.! Determination and the right equipment are all that’s needed to make cycling a success for you.
Pictures: Crank arm shortener, aaron’s bike arm, emily’s bike foot, hand crank bike