Orthotic Stance Control and Microprocessor Knees

Evolving from KAFOs to SCO’s

Lawall Prosthetics & Orthotics has been fitting it’s patients with the right orthotics since 1977. When it comes to knee orthotics, there are a couple of terms that are helpful to know:

KAFOs

Knee-ankle-foot-orthoses (KAFOs) are devices that help those with weak or absent quadriceps muscles walk independently. However, traditional KAFOs only lock when in full extension. This provides stability for the lower limbs but can also cause gait deviations that develop over time from the patient having to compensate for their movements. Additionally, KAFOs do not allow for knee flexion, which means the patient often has to extend more energy to use them.

free walk orthosis

Stance Control Orthosis

Stance control orthosis (SCO) designs are a type of KAFO that automatically release the knee, allowing swing phase flexion and extension. They accomplish this while still locking the joint during stance, blocking flexion, and providing stability.There is a bit of a learning curve when switching from a KAFO to an SCO. This is likely because, when experienced with KAFO, you have likely developed gait patterns that compensate for walking with a standard locked KAFO. Because of this, it may be challenging to immediately take full advantage of the capabilities offered by the SCO, and many users have to readjust their gait.

However, the ability of SCOs to provide knee flexion when in the swing phase means they will have a much more natural gait pattern. A more symmetrical gait pattern means that SCO users will limit the extra stress they place on their body compared to those who use a traditional KAFO. It will also reduce the energy expenditure needed to ambulate. These advantages can be a real game changer for many patients.

Types of Orthotic Stance Control Orthoses (SCOs)

Free Walk

Free Walk is a KAFO that provides a smoother, more natural gait for those unable to stabilize their knee without assistance.

It utilizes stance control technology to lock when standing but unlock when swinging the leg, providing a more efficient gait. Additionally, added security is offered to the user since the knee joint automatically locks when the joint is fully extended, even before contact is initiated.

freewalkorthosisbeige

One of the primary benefits of the Free Walk is that it allows the user to expend less energy when walking while also reducing the load sustained by the back, hips, and knee joints, leading to less pain when operating.

The Free Walk is a comfortable option with its unilateral joint bar design, and the knee joint covers protect the joint and your clothing. The covers are also removable, making for easy sanitation.

The Free Walk looks different from other KAFOs because it consists of a unilateral joint bar design, which offers increased comfort to its users. This is in comparison to the KAFOs that cup all around the thigh and down the side of the calf, which is a much bulkier design.

This design, with its open frame, also makes the FreeWalk lighter and cooler, making it more comfortable to wear in the warm summer months. Additionally, the quick-release hooks make it quick and easy to put on and take off the Free Walk.

Emag Active

EMag Active

E-MAG Active is a knee orthosis that helps with stabilizing the knee joint. It utilizes an intelligent sensor system to measure the leg position while walking and then uses this information to control the orthosis joint.

Like other microprocessor KAFOs, the knee joint of the EMag Active automatically unlocks when walking, allowing the leg to swing freely. The PreLock function of the E-MAG Active then locks the knee joint for the stance phase, even before the leg has been fully extended. It is also a viable choice for those with no ankle functionality.

E-MAG Active utilizes a magnet to open and close the joint, allowing your hands to remain free. The magnet works quietly as well, making its actions inconspicuous when going about your day. Additionally, the natural gait pattern supported by the E-MAG Active means that there is virtually no need for compensating movements, which relieves strain on your body and prevents the pain and other symptoms of uneven gait that can occur with time.

The E-MAG Active allows for actions such as cycling by changing the device to unlocked mode using a small button.

The battery for the E-MAG Active accommodates up to 5,000 steps, allowing you to use it for longer.

The Stride Family

The Stride Family comprises a group of versatile and interchangeable SCO systems for the knee joint. The appeal of this family is that each component offers unique and specific features that can be used together to achieve the user’s needs. Additionally, it is quick and easy to change the parts and function of the orthotic because the modular parts all use the same base orthosis.

FullStride

FullStride

The FullStride is an SCO utilizing a low-profile cabling system to assist with the locking and unlocking the knee joint when in the swing or stance phase. With the FullStride, the mechanism locking the joint reengages when the user’s knee joint reaches full extension, providing stability for the stance phase.

When needed, the FullStride’s stance control capacity can easily be changed to a traditional automatic bail lock.

The FullStride is also available in a B Size, intended for smaller adults or adolescents. The addition of this size ensures a more comfortable option for younger patients that is also lighter in weight, making it easier to use since less energy needs to be expended.

SafetyStride

SafetyStride uses the same cabling system as the FullStride to automatically lock and unlock the joint during and after the stance phase. However, the key feature of the SafetyStride is that it resists knee flexion at any angle. Additionally, it does not require the user to achieve a full 180º knee flexion to activate the stance phase.

This device is especially appealing for those who frequently fail to reach full extension, as it provides that security even if they cannot fully extend their knee.

The SafetyStride can also work with the FullStride.

SafetyStride

Stride4

The Stride4 is the newest addition to the Stride Family. Like the other components, it is a mechanical SCO using a low-profile cabling system.

The Stride4’s joint body utilizes a mechanism with a four-bar linkage. However, the lower and upper parts do not rotate around a single center of rotation; they instead mirror natural knee motion by using some translation and rotation. This provides a more natural gait that then reduces pain associated with usage.

The Stride4 possesses an extension stop that is adjustable, allowing the orthotist to modify when the joint will enter the locked/stable state. For those looking for free motion, an orthotist can remove this feature that provides stability by fully adjusting when the extension is stopped. This then offers more options in knee joint movement.

Should the user wish to lock the joint at any point, they can press the button located on the side of the Stride4 to alternate between stance control and locked modes. Even when the locked mode is selected, though, the joint still allows approximately 3º of flexion, which helps it offer slight shock absorption for the user.

Microprocessor KAFOs

Some SCOs are also considered microprocessor KAFOs because the bending and straightening of the knee joint are controlled by a microprocessor.

C-brace KAFO
C-Brace

The C-Brace is a microprocessor-controlled leg orthosis that provides greater freedom of movement. It helps its users confidently go up and down steps, walk on uneven terrain, and go down steps one foot at a time.

The C-Brace design consists of individually fabricated foot, calf, and thigh components, with an ankle joint connecting the foot and calf parts. The fabrication process is simple, making it easier to get a device that perfectly fits your body.

The C-Brace also consists of a sensor system that continuously measures the flexion of the knee joint in addition to its angular acceleration. With this information, the C-Brace can detect the user’s current walking phase, allowing it to regulate the hydraulic resistances while also controlling the flexion and extension in the knee joint. This sensor technology makes the C-Brace’s gait pattern more responsive and dynamic, which means that the C-Brace is able to respond to everyday situations in real-time, providing stability and confidence to those who use it.

By analyzing the situations you encounter as you approach them, the C-Brace enhances safety. It does this by making real-time adjustments that help increase security when walking on uneven terrain, sitting down, or going down steps. Users can feel more confident in their orthotics’ ability to adapt to the environment in the same way their body does.

Additionally, settings for the C-Brace, such as changing to cycling mode, can be completed through the accompanying smartphone app. Through the app, your orthotist can also individually adjust your C-Brace to ensure that it works perfectly for you.

Lawall Prosthetics & Orthotics can offer all of these products and can help you choose which KAFO is right for you.

Please contact us to schedule an appointment with one of our trained orthoses.