Intelligent Stance Control Orthoses

Intelligent Stance Control Orthoses
29 Mar 2017


In the laboratories of rehabilitation technology, new doesn’t remain new for long. No sooner does an innovative assembly or product hit the market than efforts are already under way to improve on it, either through an entirely new approach or improved engineering of the original concept.

Such is the case with stance control orthoses, or SCOs, for which the initial, largely mechanical joint designs have now been taken to a new level of microprocessor control to address the specific needs of a wider range of patients. Two recently introduced products exemplify this new generation of “intelligent” SCO technology.

The E-MAG Active system extends the benefits of a stance control knee-ankle-foot orthosis and provides an added level of safety to patients with no ankle function. In lieu of an ankle sensor or weight-sensing footplate, an on-board gyroscope monitors the affected limb’s position within the gait cycle at all times and controls an electro-mechanical knee unlocking mechanism accordingly to enable flexion during swing phase and ensure a stable knee for weight-bearing.

A custom KAFO incorporating E-MAG Active knee joints is easy for patients to operate, permits variable cadence, and will accommodate a knee flexion contracture of up to 15 degrees. The system calibrates itself to “know” the user’s gait pattern and reacts to provide added safety should a sudden deviation occur. This easy-to-adjust system can be fine-tuned repeatedly as the user’s gait changes during the continuum of rehabilitation.

Another innovation: The E-MAG Active can provide auditory feedback to the patient regarding the flexion moment at the knee. This feature is especially helpful during gait training to repeatedly and successfully unlock the knee joint at terminal stance.

The E-MAG knee joint is completely enclosed, preventing clothes from becoming snagged and protecting against external impact and contaminants entering the joint. This system can be used for appropriate patients weighing up to 187 pounds.

By contrast, the Sensor Walk, can withstand users of up to 300 pounds, most of any stance control KAFO currently available. This heavy-duty orthosis, developed in conjunction with the Mayo Clinic, offers several unique features that provide the benefits of sophisticated stance control to individuals who cannot operate other SCOs.

Sensors in the knee and footplate feed data to the Sensor Walk microprocessor and unlock the knee in late-stance phase when weight has been transferred to the contralateral side and is ready for single limb support.

Gait is frequently more natural than with other SCOs, because a knee extension moment is not required to unlock the joint. After mid-stance but prior to initial contact, the Sensor Walk knee joint will lock at any degree of knee flexion, facilitating stumble recovery.

Unlike other stance control systems, which can take up six months to master, gait training for the Sensor Walk is fast and can be as simple as walking for a time between parallel bars. Many users quickly gain sufficient confidence to climb stairs, change cadence during ambulation, and walk on uneven terrain.

The Sensor Walk can be set to function as a fully locked or free-swinging knee to accommodate changes in the patient’s ability and special circumstances. Like the E-MAG Active, the Sensor Walk uses a rechargeable lithium ion battery that gives active wearers a full day of service.

This next generation of SCOs illustrates the exciting future of orthotic limb rehabilitation. Call our office today for more information. Your initial consultation is free. Offices located throughout southeast Texas in Beaumont, Nederland and Jasper.

LeTourneau Prosthetics