Some people want to run before they can walk – and who can blame them! Össur understands what it takes to move freely and most fast, hence its range of high performance prosthetic feet for people who want to achieve.
Experience the comfort, power and agility that make up the building blocks of high energy activity. From chasing world records to jogging with the dog, Össur’s sports feet are renowned for keeping people moving.
Superior biomechanical expertise, combined with invaluable feedback from top athletes and active people, has helped guide the following designs. Watch them in action when Team Össur get on the field, and prepare to be inspired.
Flex-Foot Cheetah®
It has broken all manner of records and, like its namesake, the Cheetah runs like the wind. Just watch athletes like Marlon Shirley, Oscar Pistorius or April Holmes, all three of whom are world record holders who ran their way into the history books on the Cheetah. An agile sprinting foot, it is used mainly by people with below-knee amputations, but is also suitable for some above- knee users. The design captures the running characteristics of the Cheetah, the world’s fastest land animal. It replicates the big cat’s hind leg, whose foot extends and reaches out to paw at the ground while the large thigh muscles pull the body forward.
Comfort, power and agility
If you think Össur’s sports feet could help you achieve your sporting ambitions, discuss the different options with your prosthetist.
What is it?
Össur's Flex-Foot Cheetah is a J-shaped, high performance carbon composite prosthetic sprinting foot. The prosthesis is designed to mimic the action of the anatomical foot/ankle joint of able-bodied runners and help compensate for the user’s impaired physiology.
Over the past decade, scores of amputee athletes have used the Flex-Foot Cheetah from Össur to compete at international levels of sport. In fact, the Flex-Foot Cheetah is considered the leading choice in prosthetic feet for both elite and recreational amputee athletes.
The technology used in the Flex-Foot Cheetah has existed since 1997, and has not experienced any significant updates since that time.
Who is it for?
Össur's Flex-Foot Cheetah was designed for unilateral/bilateral transtibial and transfemoral (above-the-knee and below-the-knee) amputees who wish to participate in running or sprinting sports at competitive and/or recreational levels.
How does the Flex-Foot Cheetah work?
Össur's Flex-Foot Cheetah is a uniquely designed prosthetic foot that features proprietary carbon technology to efficiently store and release energy produced by the user while running. When a user is running, the prosthesis’ "J" curve is compressed at impact, storing energy and absorbing high levels of stress that would otherwise be absorbed by the runner’s ankle, knee, hip, and lower back. At the end of stance phase, the "J curve " returns back to its original shape, releasing the stored energy and propelling the user forward.
The Flex-Foot Cheetah is designed to have more layers of carbon at higher stress points, such as the apex of the "J" curve, and less carbon where more flexibility is needed, such as the toe portion. Importantly, the Flex-Foot Cheetah has no heel component. This ensures that the prosthetic foot’s reaction accurately mimics that of an able-bodied runner replicating both the stance and swing phases of running.
What does this mean for the amputee?
Prosthetic feet, like shoes, are designed for specific activities. Running or participation in other sports with a normal prosthetic foot can cause discomfort and potential injury. It also may be fatiguing to the user, typically requiring they expend disproportionately higher amounts of energy. Össur's Flex-Foot Cheetah was specifically designed for running, allowing amputee athletes to train more effectively and with less risk of injury than if they used prosthetic feet designed for normal daily activities. The smooth reaction and dampening effect of the Flex-Foot Cheetah also allows the user to focus on the task at hand, and not on what the foot is doing.
How is the Flex-Foot Cheetah designed?
The prosthesis’ “J” curve shape somewhat resembles the hind quarter of a Cheetah, the fastest animal on land. The carbon technology featured in the Flex-Foot Cheetah is available in a variety of configurations to meet a user’s individual needs. The prosthesis’ thickness and resulting stiffness of the foot varies according to a user’s body weight, residual limb length, and foot alignment in relation to their running style. This can also improve the foot’s durability. A prosthetist may also customize the toe shape and the tread plate attached to the bottom of the foot. Typically, the spike plate of a sprinting shoe or the sole of an athletic shoe are applied to the foot’s carbon toe to assure traction and conformity to the running surface.
Is the Cheetah a bionic foot?
No. Bionic limbs typically incorporate artificial intelligence, including sensors, microprocessors, and sometimes even motors to supply assisted movement and real-time adjustments for the user, based on feedback captured throughout their gait cycle.
In comparison, Össur's Flex-Foot Cheetah is a non-mechanized prosthetic running foot, which returns a portion of the energy stored during the loading phase of running. Studies have shown that the Flex-Foot Cheetah can return around 90% of the energy stored in it. This is far less than a normal able-bodied foot and leg, which has been shown to return 249% of the stored energy.