k12 prosthetics, energy storing prosthetic knees k12 prosthetics, advance | enhance | empower
k12 prosthetics for high activitie amputees
Skiing with the XT9


The patented XT9 Energy Storing Prosthetic Knee functions differently than any other knee. It is the only Above Knee prostheses that mimics the functions of the quadriceps in high activity sports. The XT9's specialized "coil over air" shock system/control unit makes the XT9 the only 'energy storing' prosthetic knee on the market. As the pressure is applied to the limb, the knee bends, compressing over 400-550+ pounds of progressive energy in the coil spring and air shock combined. This tension, combined with adjustable hydraulic damping, acts supportively as the quadriceps would in any high impact situation. The knee is allowed to bend until it comes to a rest against the titanium hard stops, at which point the energy that has been built up and stored in the spring system is ready to release, returning the athlete to a ready stance.
The XT9 Energy Storing Prosthetic Knee

In activities such as snowboarding, which have often been impossible for amputees to enjoy with an artificial limb, the XT9 works naturally providing constant support and dynamic flexion as the rider turns, absorbs bumps and rough terrain, and even performs jumps and tricks.The heavy duty support which the XT9 knee offers an amputee is what allows so many high energy sports to now be enjoyed. The XT9 High Activity Knee has adjustable stance which allows the user to set an active stance which suites his or her activity and level of ability. Unlike other prosthetic knees, the XT9 is capable of supporting the user in an activity stance and works dynamically as a natural limb would do.

The XT9 Prosthetic Knee is made to the highest standards possible. It is the only high activity knee that is warranted for water use and high impact from extreme sports! Each piece of the limb is CNC machined from aircraft grade T6 aluminum alloy, stainless steel and high strength titanium. That makes this prosthesis one of a kind and a new leader in its field.

All aluminum parts on the XT9 prosthesis are anodized to military spec. "Mil-A-8625 Type 2 Class 2" giving them ultimate corrosion resistance, toughness against abrasion and an overall aesthetically pleasing finish. This process is just part of what protects the XT9 against corrosion and helps make it the first water proof, high activity artificial limb on the market.

All components of the XT9 are anodized aluminum, titanium and stainless steel. It is the only high activity prosthesis designed to endure use in all conditions.

The XT9's design and purpose make it an extremely versatile and revolutionary prosthetic leg. Amputees are using this limb to accomplish things that were once never dreamed of with an artificial limb!



  • The XT9 is fully adjustable for differing user weight, aggressiveness and activity.
  • The XT9 is durable and lightweight.
  • The XT9 is 100% corrosion resistant and is made to endure extreme climates including cold weather, water, sun and dirt.
  • The XT9 is the only prosthetic knee of its kind, offering a large range of uses at an incredible price!
  • The XT9 comes with the best warranty in the industry! Full lifetime warranty against manufacturing defects in workmanship and materials, plus a 30 month limited warranty against wear and tear.






Will my Insurance cover the XT9?

Is the XT9 waterproof?

Is the XT9 good for everyday use?

Can I buy the XT9 from you directly or do I need to go through my Prosthetist?






  • European four hole pattern for compatibility to pyramid adaptors at top and bottom.
  • Weight limit 295 lbs (133 Kilograms).
  • Weighs 32 ounces (907 grams).
  • Range of flexion 15º-120º.
  • 8.259"x3"x3".
  • Materials: Aluminum (mil spec hard anodized), Titanium, Stainless steel.

PDFXT9 Information Packet (PDF)

PDFXT9 User Manual (PDF)

SymBiotechs USA prosthetics are 100% made in the USA
XT9 prosthetic knee CE mark CA011895



SymBiotechs USA contributes a portion of prosthetics sales to charity


Snowboarding | Telemark skiing | Alpine skiing  | Cross-country skiing  | Waterskiing |
Surfing   | Wakeboarding  | Skateboarding  | Rock climbing  | Ice climbing  | Rollerblading | Ice hockey | Ice skating  |
...and more!
 K12 World News

•First all amputee team climbs
El Capitan unassisted...>>

•K12 Prosthetics creates
most advanced carbon fiber
prosthetic knee frame
ever made...>>

•Snowboarding makes
it into the 2014 Paralympic
Games in Sochi Russia...>>


Just a few short years ago, new amputee were being told they would never live the full, active lifestyle they wanted to again. They were told that they could still be active, but it would require a change of activity, and a change in technique.
Now, thanks to the World's first energy storing prosthetic knee, the XT9, amputees are living normal, healthy and active lifestyles the very sports they were told would never be possible, like snowboarding, are now being added to the Paralympic Games because of their popularity and accessibility.


• First all amputee team to ride
the Baja 1000 needs your help! 
Check out the video here>>

• Help CAF take a more
active lifestyle to Africa! 
Learn how you can help
here >>


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