A Reciprocating Gait Orthosis (RGO) is a medical device designed to enable walking for individuals who experience significant weakness or paralysis in their lower limbs. This external frame allows a user to maintain an upright posture and generate a coordinated walking motion. It achieves this by mechanically linking the movement of the two legs, ensuring that a step taken with one limb assists in advancing the other. The RGO provides stability and support for ambulation for individuals who might otherwise rely solely on a wheelchair for mobility.
Defining the Reciprocating Gait Orthosis
The RGO is a custom orthosis that fits into the category of a Hip-Knee-Ankle-Foot Orthosis (HKAFO), distinguished by its interconnected design. The structure begins with custom-molded shoe inserts or foot plates that attach to ankle-foot orthosis (AFO) sections. These sections often include a locked ankle joint for stability during standing and weight transfer. These lower sections connect to thigh cuffs, which incorporate mechanical knee joints that are typically locked to prevent unwanted flexion during the gait cycle. The entire bilateral leg system is then secured to the torso via a rigid pelvic band or a thoracolumbar shell.
This upper body section provides trunk support and serves as the anchor for the device’s mechanism. The hip joints, positioned at the body’s natural hip axis, are the central point of the reciprocal movement. These joints are linked together by a specialized component system that is the defining feature of the RGO. This framework ensures that the body is held in proper alignment, providing the structural integrity required to stand and initiate movement without muscle function below the hips.
The Mechanics of Reciprocal Movement
The RGO’s reciprocating mechanism translates a user’s movement into a synchronized step pattern. This mechanism consists of a specialized linkage system, often utilizing a dual-cable or bar design, that mechanically couples the movement of the two hip joints. When the user shifts their weight onto one leg, they create a relative extension force on the trailing, weight-bearing hip. This extension on one side pulls on the linkage system, which simultaneously forces the opposite, non-weight-bearing leg into flexion.
This transfer generates the swing-through motion necessary for the step, effectively replacing the power normally supplied by the hip flexor muscles. The system prevents both hips from flexing at the same time, which would cause the user to collapse. To initiate the next step, the user must shift their weight back to the newly advanced leg, creating a new extension force that repeats the reciprocal action. This process allows for an alternating, step-over-step movement.
Conditions Benefiting from RGO Use
The RGO is prescribed for patient populations experiencing bilateral paralysis or severe weakness in the lower limbs, typically individuals with a neurosegmental lesion level between T4 and L3. Children with myelomeningocele, the most severe form of Spina Bifida, represent a large group of users, particularly those with upper lumbar level involvement. Individuals with traumatic spinal cord injuries resulting in paraplegia also benefit from the device. The RGO provides them with the ability to stand and ambulate, offering therapeutic benefits like improved bone density and better circulation.
Successful use of the RGO requires several physical prerequisites to ensure a functional outcome. The user must possess sufficient upper body strength to manage assistive devices, such as crutches or a walker, which are necessary for balance and initiating the weight shift. Minimal joint contractures are also a requirement, with hip and knee contractures ideally remaining below ten to twenty degrees for proper orthotic alignment. The patient must also have adequate cognitive capacity and motivation to master the training protocols required to operate the device effectively.
Implementation, Training, and Long-Term Use
The process of receiving an RGO begins with an evaluation by a physical therapist and a certified orthotist to confirm the patient meets the criteria. Following custom fabrication and initial fitting, the user enters a structured rehabilitation program focused on mastering the device. Training progresses from achieving static standing balance within parallel bars to learning the dynamic weight shift required to engage the reciprocal mechanism and take steps.
The user must learn to coordinate the weight shift with the use of crutches or a walker to maintain stability during the transfer of the center of gravity. Although the RGO facilitates a more natural gait, ambulation remains metabolically demanding. The energy expenditure when walking in an RGO is significantly higher. Consequently, the RGO is often utilized as a supplemental mobility device for therapeutic standing, household ambulation, and exercise, rather than for long-distance travel.
Long-term use requires routine maintenance of the mechanical joints and cables to ensure smooth, efficient operation. For pediatric users, adjustments or refabrication may be necessary to accommodate growth and developmental changes. Despite its limitations in speed and endurance, consistent use of the RGO provides health benefits, including reducing the risk of pressure ulcers and encouraging cardiopulmonary activity. The device restores a measure of independence and allows for standing and eye-level social interaction, contributing to psychosocial well-being.