Off the Shelf - OFS (Pre-Fabricated Orthosis)
Fabricated for the average sized person and are usually only minimally adjustable. Can come in sizes small, medium, and large and for left or right foot.
Custom Fitted (Semi-Custom)
A premade sized device that is fit and/or modified to a patient. Semi-custom may be an off the shelf brace used as the basic structure with specific parts added that are custom made.
Custom Designed
An individually designed, crafted, and fitted brace, made specifically to meet the unique needs of an individual. A custom brace usually requires casting and fitting before the brace is manufactured.
Electronic
A custom-made brace that can include a motor, hydraulics, and other mechanical devices. Frequently use computer sensor input to assist with the wearer’s functioning.
Mechanical Assist
Uses various mechanical principles, mechanical devices and energy storing/releasing materials, such as graphite and carbon fiber, to accomplish desired functions.
Stance-Control
Device with an adjustable brake mechanism to add stability to an orthotic knee joint.
Tri-planar control
Controls the movement of a limb in all three directions or “straightens out the leg/foot”. Sometimes this requires corrective pressures at multiple places on the foot, ankle, leg to correct this movement:
- Up and down/forward (sagittal plane) – Example: the foot is in a dropped or not dropped position
- Side to side (coronal plane) – as in the ankle turning in or out or the knee bending in (valgus or knock-knee) or out (Varus or bow legged)
- Twisting toward or away from straight ahead (rotary) -- Example: foot/toes turning in (pigeon toed) or foot/toes pointing out, or the kneecap pointing inward or outward when the person is putting weight on that leg
When orthotists say they practice “tri-planar control,” they mean they use a three-point pressure system. They may usually do this to correct a problem only at one site, not at multiple sites simultaneously. Patients are encouraged to get clarification about which sites are addressed with tri-planar control.
Dynamic Response
A function of the leg brace that allows it to store energy and later release that energy to help “propel the wearer forward”. Part of this is also called “floor reaction” or “ground reaction” forces—this is why the main control at the knee should be in front of the leg instead of behind it.
One mechanism that makes this dynamic response possible is a carbon fiber graphite construction that allows the brace to flex (bend) when weight is applied to it and then actively recoil back to its original position when the weight is released (the foot is lifted off the ground).