Orthotics Glossary


Accommodative foot orthosis
a foot orthosis that conforms to the abnormal foot shape or position to equalize pressure distribution on the foot.

Air splint
an immobilizing orthosis for temporary use, consisting of air cells that are inflated to encircle the limb and joints where desired.

A closed-cell foam padding that is fabricated in various densities. Softer materials are used as an interface for a variety of orthoses but are most commonly used in spinal orthoses (i.e.,TLSOs and LSOs). Multiple densities can be used to fabricate soft body jackets.

Ankle Foot Orthosis

the descriptor of orthotic joint motion control. A joint with assist includes springs or elastics to enhance joint motion.

Bail lock
an addition to mechanical knee joints consisting of a ring of metal linking medial and lateral knee joints, passing posteriorly to the knee joint. This addition automatically locks the knee in extension. The "bail" description is taken from the handle of a metal pail that aptly depicts the appearance of the lever that controls the locking mechanism. When the patient is standing, the joints are locked in extension. For flexed knee sitting, the patient pulls up on the bail, and the knee becomes unlocked. Also known as a French or Swiss lock.

Body jacket
a generic term used to describe various spinal orthoses (TLSOs) used to immobilize and provide support to the spine.

vernacular for orthosis.

the largest bone of the foot, the heel bone. Also used as an adjective to describe a position of deformity involving fixed or tight dorsiflexion of the foot, which makes the calcaneus more prominent.

the medial and lateral metal uprights (usually round) used in lower extremity bracing to transmit forces from the shoe to the calf portion of an orthosis. The caliper fits into an attachment plate on the heel and allows easier interchangeability of shoes.

Carpal tunnel splint
a static wrist-hand orthosis (WHO) used to restrict flexion and extension about the wrist to reduce motion and pain caused by carpal tunnel syndrome.

a common term used to characterize a higher-than-average medial longitudinal arch in the foot. See also Pes Cavus.

Certified orthotist (CO)
a health professional engaged in the practice of orthotics. To obtain certification, an orthotist must successfully pass a set of national examinations. Certified orthotists have demonstrated capabilities to design, manufacture and fit orthoses and may use the initials CO, a designation given only by the American Board for Certification of Orthotics and Prosthetics.

Chairback brace
See Knight spinal brace.

Charleston Bending Brace
a “hyper-corrective” TLSO worn solely at night for the conservative treatment of scoliosis developed by Ralph Hooper, CPO. The TLSO is made from measurements of the patient that are input into a CAD/CAM computer system. Brace features a large “un-bending” moment opposite the curve as way to over correct the curve.

the method of fastening together, closing, binding or confining. Usually refers to straps on orthoses or shoes.

CO (Cervical orthosis)
often called a cervical collar. This orthosis is used to treat conditions of the cervical spine, and it may be soft or rigid. It has a variety of names, such as Thomas, Miami J, Philadelphia or Queen Anne.

Compression garments
the elastic garments used to control edema, prevent lymphodema and dypotrophic scarring, and assist venous flow.

a common hybrid plastic used in orthotics and prosthetics, consisting of a mixture of at least two types of plastic. The resultant plastic has many of the desirable features of each of the component plastics.

Copolymer Polypropylene
This plastic is used for any application requiring semi-rigid plastic. This polymer will withstand temperatures below 32°F and is less likely to fracture than polypropylene. Its is often used in lower limb orthoses.

a cloth or similar fabric spinal orthosis, or the anterior panel of various spinal orthoses. Used to increase intra-abdominal pressure. The term also is used to describe the reinforcement of firm leather or stays incorporated in the upper of a shoe to support or restrict ankle motion.

CTLSO (Cervicothoracolumbosacral orthosis)
often used in the treatment of scoliosis or high thoracic fractures.

Cushioned heel(s)
a heel made from soft cushioned material that is added to a shoe to provide a shock absorbing effect during gait. See SACH.

Custom orthosis
an orthosis fabricated to fit a single patient. An impression, a tracing or a computer digital impression of the involved body part is taken and used as a model to make the orthosis. The orthosis cannot be worn by others. High temperature plastics are often used for these orthoses. See also Splint.

Custom-fitted orthosis
a prefabricated orthosis that requires customizing or assembling to fit a patient.

the flexion of a joint in the direction of the dorsum of the body part. Often used with reference to the foot or hand.

Double-action ankle joint
a mechanical ankle joint that allows assistance or resistance of dorsiflexion or plantar flexion range of motion.

also known as footdrop. During gait, the foot plantarflexes and the toes drag on the floor because of loss of antigravitational effect from weak or absent dorsiflexors.

Dynamic orthosis
an orthosis, usually with articulations, that generally provides assistive movement with springs or elastic bands.

a plantar flexion deformity of the foot, often associated with a tight Achilles tendon.

the lateral deviation of the distal segment of a part. In the foot, eversion is a component of triplanar movement that occurs primarily in the frontal plane. In the everted position, the plantar surface of the foot is directed outward from the midsagittal plane. The distal calcaneus moves laterally under the talus with eversion.

elbow-wrist-hand-finger orthosis.

elbow-wrist-hand orthosis.

Extrinsic posting
a distinctive wedge modification added to the external part of a foot orthosis. The wedge accommodates a specific foot deformity. On weight bearing, the wedge prevents unwanted motion. It can be added to the forefoot in the case of forefoot varus leading to excessive pronation or to the rear foot in the case of, for example, calcaneal valgus.

various materials, such as cork, felt, rubber, placed between the innersole and outersole to provide leveling and cushioning in shoes.

Flexible orthosis
refers to the ability of the material used in an orthosis to bend.

Floor reaction AFO
the various forms of ankle-foot orthoses that provide knee stability during mid- to late-stance phase, usually by keeping the knee in extension. The orthoses require a dorsiflexion stop or rigid ankle to prevent the tibia from flexing over the foot. The orthotic alignment of the tibia-foot angle is critical to achieving the desired posterior ally directed force on the tibia. A modification can be incorporated to keep the knee in flexion.

FO (Foot orthosis)
an orthosis below the ankle that encompasses all or part of the foot. Used to reposition an abnormal foot or relieve pressure by redistributing weight bearing on the plantar aspect.

Four poster
a cervical orthosis to restrict range of motion of cervical vertebrae. Consisting of a mandibular support connected to an anterior sternal pad and an occipital support connected to posterior suprascapular pads. Each of the anterior and posterior connections is made up of two supports, for a total of four, hence the term four poster.

Fracture orthosis
used primarily for fractures and nonunions after conventional treatment. Fracture orthoses used for lower extremity fractures commonly allow some axial loading through the bone. Most of the forces of walking are redirected from the bone to the external structure of the orthosis.

Free motion joint
an orthotic joint that allows full range of motion in one plane. A free motion ankle joint will allow full dorsiflexion and plantarflexion of the ankle joint but will restrict subtalar mediolateral motion.

Functional foot orthosis
a foot orthosis that alters the foot position to allow the foot to function more closely to normal.

Gaffney ankle joint
a low-profile metal single-axis ankle joint. Formed into an ankle-foot orthosis by vacuum-forming plastic on top of the joint, the mechanical joint is then integrated into the orthosis to provide articulation at the ankle. The joint allows free motion in one plane. Control of range of motion of dorsiflexion and plantar flexion through stops is achieved by the final trim lines of the molded plastic around the ankle. The joints were developed by Philip D. Gaffney, Orthotic Technician, Hillsboro, Oregon.

Gillette joint
commercially available injection-molded polyurethane ankle joints. These plastic joints rely on a narrowing in the polyurethane that allows repeated bending without material fatigue. Dorsiflexion and plantar flexion occur as a result of the flexibility of the polyurethane. Gillette joints are vacuum molded into the thermo-plastic shell of ankle-foot orthoses (AFOs). Dorsiflection and plantar flexion range are controlled by the final trim lines of the plastic shells where the joints are imbedded. Developed at the Gillette Children's Hospital, St. Paul, Minnesota, and manufactured by Becker Orthopedic Appliance Co.

Gomez Orthotic Systems TLSO
An asymmetrical TLSO developed by Dr. Miguel Gomez for the conservative treatment of scoliosis. The asymmetrical TLSO is custom made to patient measurements and specifications through a series of measurements and digital imaging. The data is input into a CAD/CAM system which allows Dr. Gomez to make patient specific modifications to the TLSO, which is then fabricated from polyethylene and fit to patient. The goal of the GOS TLSO is to maintain and achieve overall patient balance and alignment as well as limit progression of the curvature of the spine.

Heel wedge SACH
a wedge of soft cushioning material added to the heel on a shoe to provide a shock-absorbing effect. It also provides a minor rockering component to the foot at heel strike by mimicking ankle plantar flexion.

High Density Polyethylene
This plastic can be used as an alternative to polypropylene. Generally used in spinal orthoses where greater rigidity is required.

Hyperextension brace
a spinal orthosis used to maintain an extended position of the spine by the application of a three-point pressure system. Various prefabricated and custom hyperextension braces are avail-able that are used to stabilize compression fractures. See Jewett hyperextension orthosis for further description.

Inflare shoe
a shoe with inward swing of shoe forepart to apply pressure and position the metatarsals in optimal adduction.

Intrinsic posting
a modification to the positive cast of the patient's foot before the plastic orthosis is molded. This modification causes the resultant orthosis, on weight bearing, to maintain the foot in the desired position. This type of posting results in a low-profile orthosis. Intrinsic posting can be used in the rear foot or forefoot section of the orthosis, for example, forefoot varus leading to excessive pronation or calcaneal valgus.

a component of triplanar movement that occurs in the frontal plane and allows the plantar surface of the foot to be directed toward the midsagittal plane. With inversion, the distal calcaneus moves medially under the talus.

Ischial brim
the proximal portion of a knee-ankle-foot orthosis (KAFO), made from plastic, leather or metal fabricated to contain the upper thigh in a cylindric or quadrilateral shape. The function redirects weight-bearing forces from the bones of the leg to the pelvis through the ischial tuberosity and surrounding upper thigh tissues.

Isocentric RGO
reciprocating gait orthosis (RGOs) developed by Wallace Motloch, C.O., Redwood City, California. The unique feature of this RGO is the connecting link between the hip joints. It pivots on a bearing in the center of the pelvic band. See Reciprocating gait orthosis.

Jewett hyperextension orthosis
a prefabricated thoracolumbosacral orthosis (TLSO) designed to maintain extension of the spine. The frame applies a three-point pressure system consisting of two anterior pads (sternal and suprapubic) and a posterior counterpressure pad in the thoracolumbar area. Frequently used during the acute stage for patients with spinal compression fractures. Devised by orthopedic surgeon Dr. E. L. Jewett, Florida.

Klenzak joint
a mechanical ankle joint used in orthoses with an adjustable spring dorsiflexion assist and plantarflexion stop. Designed by J. Klenzak.

Knee lock
the addition of a device to maintain the mechanical joint in a stable extended position. Knee locks come in various forms. Droplocks use gravity to secure a metal ring around the joint to prevent flexion. Pawl locks such as the Swiss, bail or French are easier to unlock when the patient wants to sit. These types connect medial and lateral sides of the joints through a lever located posterior to the knee.

Knight spinal brace
a lumbosacral orthosis (LSO) consisting of a posterior padded aluminum frame of pelvic band, thoracic band, paraspinal and lateral uprights. A corset front increases intra-abdominal pressure. The orthosis functions to reduce lumbar extension and restrict lateral trunk bending. Devised in 1874 by Maryland physician James C. Knight (1810-1887). Commonly called a chair-back brace.

Knight-Taylor brace
the hybrid style of thoracolumbosacral orthosis (TLSO), incorporating the increased lateral control from the Knight orthosis with the upper trunk control from the Taylor orthosis. Restricts motion in the spine in the frontal and sagital planes. See Taylor orthosis.

A synthetic, non-allergenic material used in place of sheepskin on a variety of orthoses where serious padding is required. It is commonly used when no other material will be placed between the patient's skin and the orthosis itself (e.g., Halo orthosis).

a form on which a shoe is made. The term is sometimes used to describe the shape of a shoe. For example, a straight-last shoe is one without a medial inflare of the anterior part of the sole.

Limited motion joint
a mechanical joint used to restrict the range of motion of an anatomic joint. Some are adjustable to allow controlled range of motion.

Long leg brace
vernacular for knee-ankle-foot orthosis (KAFO) or a hip-knee-ankle-foot orthosis (HKAFO).

Low Density Polyethylene
This plastic is utilized where flexibility is required.

Lumbar pad
a pad used as an accessory to a flexible orthosis (corset). It is rectangular in shape, typically 8 cm thick and 25 cm to 35 cm long and is most often applied to the lumbosacral area. Also called a Cook's shingle.

Metatarsal bar
the tread material added to the external sole of a shoe proximal to the metatarsal heads. Reduces pressure on metatarsal heads by redirecting weight-bearing forces. A metatarsal bar secondarily functions as a rockered sole on the shoe to decrease flexion of the proximal interpha langeal joints of the foot during toe-off.

Metatarsal pads
the supportive pad(s) added to a foot orthosis or inside a shoe to support the transverse arch of the foot and reduce pressure on the metatarsal heads.

Milwaukee brace
a cervicothoracolum-bosacral orthosis (CTLSO) popularized in the mid-1950s by Dr. Blount in Milwaukee, Wisconsin, for the conservative treatment of idiopathic scoliosis and/or kyphosis. Consists of a plastic or leather pelvic girdle foundation, metal uprights that are con-toured and connected to a metal neck ring, and corrective pads.

Modified Polyethylene
This plastic can be used as an alternative to low density polyethylene; it is somewhat more rigid. Generally used in spinal orthoses and in non-weight bearing type of upper and lower limb orthoses.

Molded to patient
splints made directly on the patient. Often, a low-temperature thermoplastic is heated then molded on the patient. When the plastic cools, the splint becomes more rigid. If an orthosis is made on top of a positive patient model, usually plaster of paris, it is termed molded to patient model.

MP extension stop
a metacarpal phalangeal extension stop applied to hand orthoses to limit the extension range of the metacarpal phalangeal joints.

Offset joint
a mechanical knee joint in which the axis of rotation is placed posteriorly to the uprights. A force transmitted through the uprights causes the knee to extend, providing the patient with increased stability of the knee during the stance phase of gait. The offset joint may locate the mechanical axis more closely to the anatomic axis.

Oklahoma ankle joint
a low-profile plastic single-axis ankle joint that can be formed into a plastic lower extremity orthosis to provide articulation at the ankle. This ankle joint supplies free motion in the sagital plane. Research into the development of this ankle joint was carried out in the Orthotic Section, University of Oklahoma College of Medicine.

Opponens splint
a hand-finger orthosis (HFO) used to assist opposition by stabilizing the thumb and allowing a three jaw chuck prehension grip.

an external orthopedic device using biomechanical forces to support or realign one or more body segments or to prevent or correct deformity. The origin of the term comes from the Greek ortho meaning "straight,""upright,""right," or "correct." The plural of orthosis is orthoses.

a person trained in the practice of orthotics. A certified orthotist is an individual who has demonstrated a level of competence by passing an organized set of examinations, thus meeting a standard set by many countries for ability to design, manufacture and fit orthoses. See Certified orthotist.

Outflair shoe (boot)
a shoe (boot) with a reverse outsole pattern, used to apply pressure to the foot to maintain abduction of the metatarsals or to reduce adduction.

Pavlic harness
a fabric hip abduction orthosis consisting of heel cups and medially directed shoulder straps to flex and abduct the hips. Used for the treatment of newborn hip dislocation, by keeping the femoral head in the most stable position in the acetabulum. Devised in 1944 by Czechoslovakian orthopedic surgeon Arnold Pavlic.

Pelvic band or belt
a pelvic band that serves as an anchor for hip joints when fabricating various hip orthoses and HKAFOs.

Pelvic girdle
a molded plastic, leather or cloth structure, formed to fit on the pelvis. Uprights may be attached to it, as in the Milwaukee orthosis.

Perineal straps
the belt(s) of material used occasionally in spinal orthoses that pass from the posterior aspect of the brace under the groin (perineum) to the anterior aspect of the brace. It is used to prevent the orthosis from migrating superiorly on the patient. Generally not well tolerated by patients.

Pes cavus
a common term used to describe a higher-than-average medial longitudinal arch in the foot.

Pes planus
a common term used to describe a flatter-than-average medial longitudinal arch in the foot. Calcaneal valgus, pronation, lateral rotation and abduction of the foot are often aspects of the deformity.

A closed-cell foam padding that is fabricated in three different densities known as #1, #2 and #3. The higher the number, the higher the density of cells. Density #1 is very soft and is often used as an interface for diabetic orthoses. Densities #2 and #3 are most commonly used in foot orthotics.

Polycentric joint
a mechanical joint used in orthotics. Action is in one plane with a changing center of rotation. Most commonly used at the knee, with dual gears or sliding/pivoting mechanisms. These joints attempt to track more closely the complex motion of the anatomical knee joint.

a common plastic used in the fabrication of orthoses. The high molding temperature of 175°C (350°F) to mold this plastic requires the use of a model of the patient's limb to fabricate the orthosis. Polyethylene is a durable homopolymer plastic that can be flexible or rigid, depending on the molecular weight.

a common plastic used in the fabrication of orthoses. The high molding temperature 200°C (400°F) to mold this plastic requires the use of a model of the patient's limb to fabricate the orthosis. Polypropylene is a homopolymer plastic, is durable and, depending on the molecular weight, can be flexible or rigid.

A versatile, lightweight cellular urethane providing excellent shock absorption and resiliency. It will not bottom out with extended use. Commonly used as a substitute for PPT, it is in fact the original PPT.

a wedge added to the outsole of a shoe or foot orthosis. See Extrinsic posting and Intrinsic posting.

A trademark name owned by Langer Biomechanics Group, Inc., this urethane padding was introduced in 1980 and marketed until 1992, when its name was changed to Poron. Today, materials such as "Isoloss LSM" and "Kanga Foam" are sold under the PPT trademark. (See Poron.)

the triplanar motion that, in the foot, features various proportional combinations of eversion, abduction and dorsiflexion.

Reciprocating gait orthosis (RGO)
a bilateral TLSO-HKAFO orthosis with linked hip joints so that flexion (or extension) of one hip sends an extension (or flexion) force to the contralateral side during gait. RGOs allow for a more normal bipedal gait.

the abnormal hyperextension of a joint.

a descriptor of orthotic joint motion control to restrict or prevent motion. When prescribing an orthosis for a person with weak dorsiflexors, plantar flex-ion resist may be requested.

Resting splint
an orthosis that is used to immobilize a limb segment in a desired position. Can be used at night to prevent contractures from forming.

Rocker sole
an external shoe modification, consisting of an elevation that tapers from full height to almost no elevation at the toe. This modification reduces rotational forces at the ankle joint and pressure on the metatarsal heads during the latter parts of stance phase. It is used to reduce pain when ranging the ankle joint is painful and to reduce breakage of orthoses resulting when a rigid orthotic ankle joint limits the ankle joint's range of motion. May be required bilaterally to avoid creating a leg length discrepancy. A full rocker bottom to the shoe reduces dorsiflexion and plantar flexion moments of force at the ankle during the stance phase of gait. A smoother rollover is achieved from heel strike to toe-off.

SACH (Solid ankle cushion heel)
a modification to the heel of a shoe to incorporate a soft foam wedge in the heel. The effect cushions the forces at heel strike and secondarily provides a minor rocker effect to reduce the rotational forces on the ankle.

Scoliosis brace
any number of spinal orthoses (CTLSO, TLSO and LSO) used for the conservative treatment of abnormal curvatures of the spine.

Scottish Rite brace
a hip orthosis (HO) used to abduct the hips in children with Legg-Calvé-Perthes disease. A pelvic band is connected to plastic thigh cuffs by a free motion hip joint. A telescoping bar with swivel joints joins the thigh cuffs to maintain abduction while allowing hip flexion and permitting ambulation.

Shoe buildup (shoe lift)
the shoe sole material added to compensate for a leg length discrepancy.

Siesion bandage or belt
a waist belt, usually made of cloth webbing, attached to a lower limb orthosis or prosthesis as a means of suspension.

Single-axis joint
any mechanical joint used on orthotics, including ankle, knee, hip, that has a single axis of rotation. See Polycentric joint.

SIO (Sacroiliac orthosis)
a wide belt circling the pelvis between the iliac crests and the greater trochanters to exert a circumferential force on the sacroiliac joint.

SMO (Supramallellar orthosis)
designed to extend proximally above the mallelli to maximize frontal plane stability while allowing sagital plane motion.

Sole wedge
the external v-shaped sole material added to a shoe to apply a directive force to the foot or ankle during stance.

defined similarly to an orthosis ut distinguished by the use of low temperature plastics such as aquaplast and the process of forming directly upon the patient.

Spring-assist joint
an articulated joint, usually at the ankle, that contains spring(s) to dynamically assist or resist motion in one direction.

Standing frame
various TLSO-HKAFO frame orthoses that allow children with neuromuscular deficits to ambulate and stand. Consists of a platform base with rigid tubes rising up to a knee stabilizer and extends to a corset to hold the trunk. Sometimes called an orthopodium.

Static orthosis
an orthosis without artic-ulation(s). Used to maintain a functional position of one or more joints, to prevent contractures, and to provide protection dur-ing burn or bone fracture healing. Stirrup a metal u-shaped base riveted to the sole of the shoe under the heel. Provides a distal attachment point for the medial and lateral metal uprights of the orthosis and generally incorporates an axis in the proximal end to receive an ankle joint. Various stirrup joint styles are available that allow for variations in ankle motion.

Stirrup, split
a metal base riveted to the sole of the shoe under the heel. The base has a channel to receive the medial and lat-eral uprights of the orthosis, hence the term split. This type of stirrup allows the upper part of the orthosis to be transferred to other shoes that also have a split stirrup attached.

a design feature of a mechanical joint used to prevent motion beyond a set point. May be adjustable or fixed. Ankle joints may have a posterior stop set to 90 degrees to prevent plantar flexion.

a triplanar motion which in the foot features various proportional combinations of adduction, inversion and plantar flexion.

Surgical support
the historical term used to describe various types of adjustable soft cloth or canvas spinal orthoses. These orthoses are sometimes reinforced with metal stays. Often prescribed for low back pain or after abdominal surgery to support delicate tissues during healing. Many of these are prefabricated TLSOs and LSOs that fit a range of patient sizes. Being adjustable and prefabricated, they are quickly fit and dispensed to the patient. See Corset.

Swiss lock
See Bail lock.

a padded leather strap in the shape of the letter T stitched on the side of a shoe. Used to pull a valgus or varus ankle joint into a corrected position.

Tamarak joints
similar to a Gillette joint but distinguished by a reinforcing steel cable embedded in the polyurethane for added strength and stability.

Taylor orthosis
a thoracolumbosacral orthosis (TLSO). Made with a padded posterior metal frame with two paraspinal uprights extending from a pelvic band to the shoulders. Axillary straps prevent thoracic flexion. Corset front provides increased intra-abdominal pressure. Named for the brace's developer, Dr. Charles Fayatte Taylor, a New York orthopedic surgeon.

Tenodesis splint
a dynamic wrist-hand orthosis (WHO) used in transmitting active wrist extension to achieve finger pre-hension. Used for spinal cord injury patients with residual wrist extension capa-bilities. The thumb is held in a functional position and the first two fingers are moved against it by the orthosis. Relaxing the wrist allows gravity to open the grip. Varieties have been given eponyms such as Rancho, Engen and RIC (Rehabilitation Institute of Chicago).

Three point prehension
a particular precision finger grasp where small objects are held between the thumb, index and middle fingers.

Three-point pressure
the fundamental biomechanical principle used in orthotic treatment. A three-point pressure system applies two forces to a certain segment of the body with a third counterforce between the two. Most orthoses apply force(s) to the body in such a way as to limit range of motion, prevent pain or assist movement. Forces are usually distributed over a wide area instead of a point.

Thumb post
an orthosis that is often made from a low-temperature thermoplas-tic material or leather and used to provide stability to the thumb in a functional posi-tion and allow opposition prehension.

thoracolumbosacral orthosis.

a foot orthosis designed at University of California at Berkeley Biomechanics Laboratory to correct abnor-mal positioning of the hind foot. The term UCBL commonly refers to a thermoplastic foot orthosis with generous trim lines around the posterior aspect to better con-trol the hindfoot.

a frontal plane deformity of a joint in which the distal segment angulates away from the midline.

a frontal plane deformity of a joint in which the distal segment angulates towards the midline.

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