A hip-knee-ankle-foot orthosis (HKAFO) is used to treat deformity/injury of the entire lower extremity. This high-level brace incorporates an orthotic hip joint, which stabilizes the hip and prevents abduction, adduction, and rotation. Most conditions that require such hip stability involve both lower extremities and bilateral hip/pelvic bands are used.
The most common orthotic hip brace joints used are:
· Single axis joint with locking mechanism . This type of joint allows for flexion and extension and usually includes an adjustable lock, which controls hyperextension.
· A locking hip joint that allows for two positions. This type of hip joint is either locked in the standing position, or can be adjusted to a 90 degree sitting position. This is used for highly unstable users, unable to sit with stability.
· The double axis joint , with has a flexion/extension axis, as well as a abduction/adduction axis.
The hip joint is attached to a pelvic band. Pelvic bands vary in design and material. The most stable pelvis band captures the entire pelvis and is custom fabricated using thermoplastic material. This design, referred to us a girdle, can be worn under all clothing. Otherwise, the user must remove the device for certain activities, such as using the bathroom. The least obtrusive type of pelvic band is a Silesian belt, with offers mild control of the hip. This belt, which is sometimes used in above knee prosthetic designs, is attached to an upright hip joint and goes around the user’s waist.
Orthotic hip joints are also used in higher level orthotic designs, where the user’s trunk is also involved. Such devices include:
· Reciprocating gait orthosis (RGO) , which involves a pelvic girdle with thoracic extension, hip joints, bilateral knee-ankle-foot-ortheses, and a system of cables that mimic a normal gait pattern.
· Para walker , which involves a body brace, ball-bearing hip joints, and bilateral knee-ankle-foot-orthoses. The device is operated using trunk movement and is used for spinal cord injury victims.
· Parapodium , which involves a show clamp, uprights, knee block, and trunk panels. This device allows pediatric myelodysplastic patients to stand without crutches and use their hands for various activities.
· Standing frame , with if often used for children learning standing balance and swing-through gait. This does not permit for hip and/or knee flexion.