Designed with You in Mind

Lower limb amputees deserve more from their prosthetics. More freedom. More comfort. More opportunities to move forward without being held back by the limitations of traditional carbon prosthetic devices.

Ability Dynamics designs state-of-the-art prosthetic foot products, with a patient-first focus on flexibility, like nothing else on the market today. Innovative thinking, coupled with our unique glass composite, has resulted in the new RUSH Foot® design. Demonstrating radical simplicity and eliminating the frustrations amputees face today.

RUSH Foot users report and unmatched range of motion from our unique roll-through design allowing for super smooth transition from heel strike through toe-off with no dead spots in between. The RUSH Foot helps maintain a natural, smooth gait even in rugged or uneven terrain.

The performance of the RUSH Foot speaks for itself. Virtually indestructible even in the most extreme conditions. Carbon feet don’t stand a chance.

Ask your prosthetist about the RUSH Foot today.

Top

RUSH Foot Key Design Components

Material

Glass based composites have excellent strain capability, and are 3x more flexible.

Glass composites are more durable than Carbon Fiber composites.   Stress points won’t fail when subjected to stress, water or impact.

Glass fiber composites do not soften over time.

Fail Safe Material: If glass fiber composite fails (which is rare) they do not fail catastrophically.  Should a failure occur…it would be by delamination in a way that only partially compromises the structure, leaving some support to save the user from an unexpected fall; unlike carbon fiber.

Glass fiber composites provide increased flexibility, durability and result in a more natural gait.

Instep

Designed to promote tibial progression around the ankle.

The bracket pyramid weight line is set at 70% of the length. Standard weight line at the pyramid is typically 66%.

The longer overall length in combination with the 70% weight line combines to provide the longest toe lever in the industry. This is important in the fact that it reduces gait deviation.  Longer toe levers reduce the requirement in the hip to compensate for the shorter step; thus, promoting a more natural gait.

Rocker Bottom/Sole Plate

The rocker bottom is the primary contributor to the smooth roll over from heel strike to toe-off.

Upon heel strike the rocker bottom flexes to allow a smooth continuous transition from heel strike to toe off. The rocker bottom maintains a continuous line of contact. As A result, there is not the sensation of a flat or “dead spot” at midstance.

Smooth transition from heel strike to toe off requires less energy to walk or run. Over the period of a day, the energy savings adds up.

The continuous contact of the rocker bottom provides midstance contact AND midstance support.

Download the Step Analysis document here.

Step Analysis

Heel Shock

Users of the RUSH Foot®  products often state that the heel shock feels like their “real heel”. The elastomeric material has a nonlinear spring rate that brings the foot to a comfortable stop.

The heel shock material has been formulated to bring an incredibly high energy return in excess of 90%.  By providing high-energy return and comfort, patient fatigue is reduced.

The material in the heel will not fail or break down over time. It is extremely durable and will not fail due to fatigue cycles. Unlike composite heels, the RUSH Foot®  heel shock will not fail.

Overall Length

The RUSH Foot® is generally the longest composite foot on the market and significantly assists in reducing gait deviation in ambulation.

Toe lever

*All feet shown are 27cm in length.

Toe Bond Adhesive

The aerospace-grade adhesive eliminates catastrophic failure commonly experienced by amputees wearing inferior prosthetic feet.

RUSH Foot Performance Characteristics

Roll-Through Analysis

One of the strongest characteristics of a comfortable foot is the roll through characteristics. The RUSH Foot® products provide a continuous line of contact from heel strike, through the mid-stance, to toe off. The continuous roll-through removes the sensation of “dead spots” or flat spots during gait. The smooth action reduces abrupt shifts in the socket between the skin and the socket reducing shear loads.

The smooth roll-through of the foot requires less energy to transition from heel to toe. Often the result of this is an increase in self-selected walking speed as well as a more natural looking gait.

Comfort

The RUSH Foot® provides an extremely comfortable gait. The discussion on the roll-though analysis supports the smooth transition from heel strike to toe-off.

Continuous support on roll through provides comfort at all levels and at variable cadences of ambulation. End users report that they can walk farther than they ever did before without the worry of developing skin issues or worrying about getting too tired. Basketball players report that they can play substantially longer on the court before developing the typical “hot spots” in the socket or feel the onset of fatigue.

Those who spend a significant amount of time standing report the ability to stand longer and find a comfortable position. The continuous point of contact allows the user to rotate to find the comfortable position for the leg without being forced to a fixed position from an arch shaped foot.

Socket Issue Mitigation

Testimonials from a large cross-section of patients points to, or suggests, the smooth action of the RUSH Foot® reduces socket issues. (Refer to the comfort and roll-through sections.)

Time between socket replacements may be increased.

Patients don’t want to come in for socket issues. It interrupts their lives. One of our patients used to spend several day s a month in a wheel chair letting their residual limb heel. After wearing the RUSH Foot® they spend literally no time in a wheel chair.

Users of the RUSH Foot® report that when they used to take off other feet early at the end of their work day, they now wear it for evening activities, and until they retire to bed.

Durability

The glass fiber composite is well-suited to act like a toe spring to absorb a large spectrum of loads without breaking. This means the end user can wear a reasonably comfortable foot in terms of stiffness, and still have the foot survive the huge toe deflection loads that may come in extreme situations such as high-impact sports. Carbon fiber feet must be sized to be stiff to survive large impact loads. This leaves the end user uncomfortable most of the time when they are not using them in an extreme way.

Gait Deviation Mitigation

Patients and prosthetists regularly report that the user walking on the RUSH Foot® has a more natural gait. There are several reasons for this. Some have been discussed in prior sections.

We have patients often tell us that “I feel like I have my real foot back”, and “I feel like I can walk normal again”.

Long Toe Lever
The RUSH Foot® has the longest toe lever in the industry. The RUSH Foot® is overall the longest foot, and in combination with that, the toe is set at 70% of the length which gives a very long toe lever. During the toe off of a natural foot the toe is extended as plantar flexion as the leg is extend aft. The toe must extend in plantar flexion to maintain the body center of gravity from excessively motion. In connection with this there is also some hip movement. The only way for someone wearing a prosthetic device to compensate for the lack of toe extension or plantar flexion is to rotate the hip, tilt the hip, shorten their step, or let the whole upper body shift laterally which accentuates the classic gait deviation of an amputee with a poor quality foot. The RUSH Foot® gives the user a longer toe lever to compensate for the lack of foot plantar flexion. This mitigates hip compensation motion, reduces upper body sway, and lengthens the step.

Mid Stance Support of Rocker Bottom
Another classic gait deviation of an amputee is to drop the shoulder or sway the upper body to the side of the prosthetic in mid stance. This is required for flat feet with no mid stance support because this becomes a low point during the opposite leg swing through. To keep the swing leg from stubbing the toe the user must lift the swing leg higher, or lift the hip (which causes upper body sway) to allow the swing leg to swing through properly. The RUSH Foot® helps with this issue because the rocker bottom sole plate give mid stance lift and support during the middle of opposite leg swing phase. This allows the swing leg to swing through more naturally and reduces gait deviation.

Smooth Continuous Motion
The rocker bottom sole plate allows smooth continuous contact motion from heel strike to toe-off. The roll- through requires less energy and the user doesn’t have to create extra energy input to push over a flat spot and get over the toe.

Heel Strike to Foot Flat
In the natural gait of the foot the heel initiates, at heel strike, plantar flexion to flat foot. This gives a smooth un-jarring transition to the foot. Prosthetic device users with a stiff heel learn to compensate for the uncomfortable strike by dropping the upper body to ease the change in momentum. The smooth heel strike of the RUSH Foot® with soft initial contact eases the transition to the prosthetic foot such that the user can learn to walk naturally without anticipated stiff heel strike. The action of the RUSH Foot® flexes in the instep to allow the foot to move to flat foot quickly and naturally. Users of the RUSH Foot® often quote “I feel like I have my real heel back”.

Energy Return

Toe
The toe-off of the RUSH Foot® is driven by the instep. The classic definition of energy return is the measure of energy lost when a material is flexed. The energy return of the RUSH Foot® is the same as carbon fiber feet because most of the friction loss in the material is in the epoxy which is the same for both.
The toe-off of the RUSH Foot® has excellent energy return. Not only because of the composite material, but because the mid stance support provides a smoother energy free motion from mid stance to toe off.

Heel
The rubber elastomeric material of the RUSH Foot® products have been specifically engineered to provide exceptionally high-energy return. They can provide energy return in excess of the composite material which the end-user appreciates especially over an extended period of exercise. Better energy return in the heel means less work in the socket interface to keep the body moving.

No Split Toe

The split toe is a common design feature in carbon fiber feet. This feature allows rotation as inversion/eversion without an excessive amount of torque applied. End users find this feature more comfortable when walking on uneven terrain. The problem with the split toe is that both sides of the foot need to be in contact. If the user only catches part of the foot on a ledge, the toe flexes excessively and could fail. To compensate for ½ loading, manufactures make the toe more stiff, resulting in regular walking being less comfortable and overly stiff.

The RUSH Foot® is engineered to have the appropriate amount of inversion and eversion without a split toe. This means that during normal flat ground walking the toe is engineered for maximum comfort, and if the user only catches ½ the foot on a curb, they will feel confident in the toe reaction as it will not over deflect.

Top

Which RUSH Foot is Right For You?

81_Icon

The RUSH LoPro/RUSH81 is designed for:

Low-profile build

  • K3 or higher activity level
  • Moderate to high activity
  • Individuals with LESS THAN 6.5” of clearance.
  • BK, Knee Disarticulate, Bilateral or AK (or higher)
  • Individuals with long limbs, limited clearance and/or requiring additional components such as a vacuum units, torsion units or shock absorption units
  • Individuals who demand a smoother gait
  • All-terrain activity
  • Effective June 1, 2017, the RUSH81 is also known as the RUSH LoPro.

US Learn more button

International Learn more button

76_Icon

The RUSH Chopart/RUSH76 is designed for:

  • Individuals with Chopart, LisFranc, Pirogoff, Boyd and partial foot prostheses
  • Direct lamination
  • Durability and flexibility for the longest amputation levels and partial foot prostheses
  • Effective June 1, 2017, the RUSH76 is also known as the RUSH Chopart.

US Learn more button

 

International Learn more button

87_Icon

The RUSH Rover is designed for:

  • Patients with low OR high clearance, limited by clearance or build height
  • The most extreme loads of high-impact patients, K3 or higher
  • BK, Knee Disarticulate, Bilateral, AK or Symes
  • Patients tired of breaking extreme low profile feet
  • Patients tired of sacrificing flexibility in a build height less than 2.5”
  • Patients tired of being told they have little to no options in feet selection
  • Ultra-low profile build (Just under 2.5”)
  • Individuals who demand a smoother gait
  • Sizes 22-30cm
  • All-terrain, all-weather activities
  • Patients desiring cosmesis

US Learn more button

87_Icon

The RUSH Kid is designed for:

  • The pediatric patient that has broken every carbon foot and needs something durable
  • The most extreme loads of high-impact pediatric patients, K3 or higher
  • Ultra-low profile build (1.75”)
  • All pediatric patients with low OR high clearance, less than 2” of clearance, limited clearance or Symes amputation.
  • BK, Knee Disarticulate, Bilateral or AK.
  • Sizes 19-21cm
  • All-terrain, all-weather activities
  • Patients desiring cosmesis

US Learn more button

87_Icon

The RUSH HiPro/RUSH87 is designed for:

  • High-profile build
  • K3 or K4
  • High impact, extreme users
  • Individuals with a MINIMUM clearance of 6.5” or greater
  • BK, Knee Disarticulate, Bilateral or AK (or higher)
  • Individuals who demand a smoother gait
  • All-terrain activity
  • Effective June 1, 2017, the RUSH87 is also known as the RUSH HiPro.

US Learn more button

 

International Learn more button

87_Icon

The RUSH ROGUE is designed for:

  • Individuals seeking ultra-comfort in the socket during all levels of use
  • Users seeking torsion relief to ease load on joints and in the socket
  • Progressive torsional resistance to +/- 8 degrees
  • Additional vertical shock absorption
  • Additional ground compliance
  • Minimal additional weight increase offset by performance
  • High-profile build
  • K3 or K4
  • High impact, extreme users
  • Individuals with a MINIMUM clearance of 6.5” or greater
  • BK, Knee Disarticulate, Bilateral or AK (or higher)
  • Individuals who demand a smoother gait
  • All-terrain activity

US Learn more button

Top
Loading…