About alleles above knee leg covers

Our Above Knee (AK) shape has been developed over the years to restore the appearance and silhouette of the leg, while allowing the wide variety of prosthetic knees available on the market to move freely. Our Above Knee prosthetic covers start at the top of the footshell and go to the apex of the knee unit, but do not cover the thigh.

We have made measuring as quick and intuitive as possible, needing only the length and circumference to manufacture the cover. This makes ALLELES Above Knee covers a low time investment option for many clinicians, and an exciting finishing touch for your clients!

how to measure an above knee cover

Our AK covers require two main measurements: The Length and Circumference.


The Length Measurement is taken from the apex of the knee unit, all the way down to the top of the footshell. Using this as a starting point, remove half an inch to an inch to ensure that there will be a gap between the bottom of the cover & the top of the footshell. Typically, if the patient’s ankle is more dynamic, you will want to remove the full inch, whereas less mobile ankles will be fine with a half inch gap. The gap gives the prosthetic foot room to move without impacting range of motion. If the cover is too long, constant impact from the foot can crack the cover.

Keep in mind that the length measurement you provide will be the length that is manufactured, so please remove the gap before recording it in your order.


For the Circumference Measurement, please measure the widest circumference of your patient’s sound limb (calf). This measurement will be used to create the outside circumference of your patient’s cover. 

If a patient is a bilateral amputee, please feel free to select a size that suits them.

These two measurements will be the basis of the cover, and further adjustments can be made to accommodate any particular needs your patient may have.

back shapes for above knee covers

There are two back shape options for ALLELES Above Knee Covers:  Racer Back and Sport Back. Though the Racer Back has more coverage, neither back shape is fully enclosed down to the ankle. The shapes were strategically created not to interfere with the foot components, therefore allowing us to offer our covers to a wider range of clients. If we were to encompass or fully enclose the ankle, it creates excess bulk and causes the cover to lose its anatomical shape.

The Racer Back has ankle tabs for a more complete silhouette.

The Sport Back features an open ankle which allows for larger, more dynamic foot components.

heavy duty material for above knee covers

Above Knee covers can be ordered with either the Standard or thicker Heavy Duty material. The Heavy Duty line of AK covers has all of the same measuring requirements and design options as the regular material with an added level of protection and durability. The main differences include:

• Typical weight is approximately  2 lb, compared to 1lb for a regular AK cover
• The Heavy Duty covers are less flexible, and can be more effort to put on and take off

Heavy Duty covers are an excellent option for clients who are harder on their components. We typically recommend this option for bilateral amputees or for anyone concerned with durability.

Above knee cover adjustments

Based on extensive feedback from patients and clinicians, we have identified a few circumstances that require additional information for Above-Knee clients.

If you have a Polycentric Knee, please include the additional information listed below in your order:

• (1) Knee Unit Measurement;
• (2) Make & Model of Knee.

We will use the knee unit measurement to move the top strap below the knee mechanism so that there is no interference with the functionality of the knee 

If you use a TOTAL KNEE please include the additional information listed below in your order:

• (1) Polycentric Knee Unit Measurement

We will use the knee unit measurement to move the top strap below the knee mechanism so that there is no interference with the functionality of the knee.

*NOTE: we will change the top profile of the cover to sit below the Total Knee ‘Hammer’ UNLESS the ‘Heavy Duty’ Material is selected.

If you have a High Profile, Blade, Microprocessor, or Hydraulic Foot, please include the additional information listed below in your order:

• (1) Measure from Top of Footshell to Top of Foot Unit. 

We will make sure to move the bottom strap above the build height of the foot unit so that there is no interference with the functionality of the foot.

We will not require any additional measurements for TK covers, but we will require that you mention that the cover will be used on a Through Knee Prostheses.

We do alter the shape of the cover and placement of the calf wings so that there is as minimal interference with the prosthesis as possible.

how to put on an above knee cover (Straps)

All of our covers come equipped with two polyurethane straps that secure the cover to the prosthesis. These military grade straps are manufactured in the USA and have proven to be more durable than using a hard connection. 

Based on years of R&D and user feedback, we have found that hard connections are a reoccurring failure point in the cover. Because the straps have some give, it allows the constant movement created from each step to be dispersed throughout the cover rather than through a rigid connection that would fail over time.

1. Grasp cover by ‘wings’ (covers are slightly flexible)

2. Flex cover wide enough to fit around prosthesis componentry

3. Thread strap up through buckle from underneath

4. Pull strap back overtop of buckle to engage ‘Hook’. Lastly, tuck tail into cover or trim excess once you know necessary length

above knee straps

tips & tricks

How to Keep Your Cover from Rotating: Although the straps are intuitive, there is a way AK clients can better secure their covers. If a cover is rotating, it is typically because the bottom strap is not done up tight enough.

In order to do the bottom strap up as tight as possible, thread it as close to the inside of the cover as you can. This will allow you to engage 2-3 strap-holes tighter helping to eliminate rotating.