Orthosis

An orthosis (Greek: ortho, "straighten" or "align"; Plural: orthoses) is an externally applied device used to modify the structural and functional characteristics of the neuromuscular and skeletal system. An orthosis may be custom made by a specialist or prefabricated and available over-the-counter.

Function
An orthosis may be used to:
 * Control, guide, limit, and or immobilize an extremity, joint, or body segment
 * Restrict movement in a specific direction
 * Assist movement in a specific direction
 * Reduce weight bearing forces to a particular area
 * Aid in rehabilitation or healing
 * Directly or indirectly reduce pain
 * Otherwise correct the shape and/or function of the body

Manufacture and Materials
Orthoses were traditionally made by following a tracing of the extremity with measurements to assist in creating a well fitted device. Later the advent of plastics as a material of choice for construction necessitated the idea of creating a plaster of paris mold or fiberglass cast of the body part in question. This method extensively is still used throughout the industry. Currently CAD/CAM, CNC machines and even 3D printing are involved in orthotic manufacture.

Orthoses are made from various types of materials including thermoplastics, carbon fibre, metals, elastic, fabric or a combination of similar materials. Some designs may be purchased at a local retailer; others are more specific and require a prescription from a physician. Over-the-counter braces are basic and available in multiple sizes.

By body segments
Orthoses are usually classified by an acronym describing the body segments which they affect. For example, an ankle foot orthosis ('AFO') affects the foot and ankle, a thoracolumbosacral orthosis ('TLSO') affects the thoracic, lumbar and sacral regions of the spine.

By function
Orthoses may also be classified by the function of the AFO. For example, the Dorsiflexion Assist AFO or the Patellar Tendon Bearing AFO.

By place of origin
When new designs of orthoses are the primary innovation of a single entity, that design may be commonly known by it's brand name or place of origin. For example, the Richie Brace, the Arizona AFO, or the UCBL (University of California at Berkeley Laboratories) foot orthosis.

Upper Extremity Orthoses
Upper extremity (upper-limb) orthoses are mechanical or electromechanical devices applied externally to the arm or segments thereof in order to restore or improve function, or structural characteristics of the arm segments encumbered by the device. In general, musculoskeletal problems that may be alleviated by the use of upper limb orthoses include those resulting from trauma or disease (arthritis for example). They may also be beneficial in aiding individuals who have suffered a neurological impairment such as stroke, spinal cord injury, or peripheral neuropathy.
 * Static orthoses- These devices are intended to limit motion. They can provide rigid support for fractures, inflammatory conditions of tendons and soft tissue, and nerve injuries
 * Dynamic/functional orthoses- In contrast to static orthoses these devices permit motion, on which their effectiveness depends. These types of upper-extremity orthoses are used primarily to assist movement of weak muscles. Some dynamic splints have a dual or bilateral mechanism for providing tension, safely accommodating moments of spasm and thus limiting (or avoiding) soft-tissue injuries

Types of Upper Extremity Orthoses

 * Upper-arm orthoses
 * Clavicular and shoulder orthoses
 * Arm orthoses
 * Functional arm orthoses
 * Elbow orthoses
 * Forearm-wrist orthoses
 * Forearm-wrist-thumb orthoses
 * Forearm-wrist-hand orthoses
 * Hand orthoses
 * Upper-extremity orthoses (with special functions)

Lower Extremity Orthoses
A lower-limb orthosis is an external device applied to a lower-body segment to improve function by controlling motion, providing support through stabilizing gait, reducing pain through transferring load to another area, correcting flexible deformities, and preventing progression of fixed deformities.

Foot Orthoses (FO)
Foot Orthoses—comprise a specially fitted insert or footbed to a shoe. Also commonly referred to as "Orthotics" these orthoses provide support for the foot by distributing pressure or realigning foot joints while standing, walking or running. As such they are often used by athletes to relieve symptoms of a variety of soft tissue inflammatory conditions like plantar fasciitis. They may also be used in conjunction with properly fitted orthopedic footwear in the prevention of foot ulcers in the at risk diabetic foot.

Ankle Foot Orthosis (AFO)
An ankle-foot orthosis (AFO) is an orthosis or brace (usually plastic) that surrounds the ankle and at least part of the foot. AFOs are externally applied and intended to control position and motion of the ankle, compensate for weakness, or correct deformities. This type of orthosis is believed to cause chronic joint weakness if over or improperly worn. They control the ankle directly, and can be designed to control the knee joint indirectly as well. AFOs are commonly used in the treatment of disorders affecting muscle function. AFOs can be used to support wasted limbs, or to position a limb with contracted muscles into a more normal position. They are also used to immobilize the ankle and lower leg in the presence of arthritis or fracture, and to correct foot drop.

Knee Ankle Foot Orthosis (KAFO)
A knee-ankle-foot orthosis (KAFO) is an orthosis that encumbers the knee, ankle and foot. Motion at all three of these lower limb areas is affected by a KAFO and can include stopping motion, limiting motion, or assisting motion in any or all of the 3 planes of motion in a human joint: saggital, coronal, and axial. Mechanical hinges, as well as electrically controlled hinges have been used. Various materials for fabrication of a KAFO include but are not limited to metals, plastics, fabrics, and leather. Conditions that might benefit from the use of a KAFO include paralysis, joint laxity or arthritis, fracture, and others. Although not as widely used as knee orthoses, KAFOs can make a real difference in the life of a paralyzed person, helping them to walk therapeutically or, in the case of polio patients on a community level. These devices are expensive and require maintenance. Some research is being done to enhance the design, even NASA helped spearhead the development of a special knee joint for KAFOs.

Knee Orthosis (KO)
A knee orthosis (KO) or knee brace is a brace that extends above and below the knee joint and is generally worn to support or align the knee. In the case of diseases causing neurological or muscular impairment of muscles surrounding the knee, a KO can prevent flexion or extension instability of the knee. In the case of conditions affecting the ligaments or cartilage of the knee, a KO can provide stabilization to the knee by replacing the function of these injured or damaged parts. For instance, knee braces can be used to relieve pressure from the part of the knee joint affected by diseases such as arthritis or osteoarthritis by realigning the knee joint into valgus or varus. In this way a KO may help reduce osteoarthritis pain.However, a knee brace is not meant to treat an injury or disease on its own, but is used as a component of treatment along with drugs, physical therapy and possibly surgery. When used properly, a knee brace may help an individual to stay active by enhancing the position and movement of the knee or reducing pain.

Spinal Orthoses
Scoliosis, a condition describing an abnormal curvature of the spine, may in certain cases be treated with spinal orthoses, such as the Milwaukee Brace, the Boston Brace, and Charleston Bending Brace. As this condition develops most commonly in adolescent females who are undergoing their pubertal growth spurt, compliance with wearing is these orthoses is hampered by the concern these individuals have about changes in appearance and restriction caused by wearing these orthoses.

There are a number of spinal orthotic designs common to assist individuals with pathologies of the neck and back. A thoracolumbar spinal orthosis (TLSO) is a plastic body jacket to immobilize the thoracolumbar spine, although that term describes any type of orthosis that encumbers the trunk, ranging from soft corsets to metal braces to strap and pad designs that affect pathologies ranging from back pain to scoliosis to fracture.

TLSOs may also be used in the treatment of stable spinal fractures. A Jewett brace, for instance may be used to facilitate healing of an anterior wedge fracture involving the T10 to L3 vertebrae. A clamshell TLSO may be used to stabilize fractures of the spine of either anterior or posterior elements of the spine in the region of T8 to L3. The halo brace is a cervical thoracic orthosis used to immobilize the cervical spine, usually following fracture. The halo brace allows the least cervical motion of all cervical braces currently in use, it was first developed by Dr. Vernon L. Nickel at Ranchos Los Amigos National Rehabilitation Center in 1955.



Prophylactic, Functional, and Rehabilitation Braces
Prophylactic braces are used primarily by athletes participating in contact sports. Evidence about prophylactic knee braces, the ones football lineman wear are often rigid with a knee hinge, indicates they are ineffective in reducing anterior cruciate ligament tears, but may be helpful in resisting medial and lateral collateral ligament tears.

Functional braces are designed for use by people who have already experienced a knee injury and need support to recover from it. They are also indicated to help people who are suffering from pain associated with arthritis. They are intended to reduce the rotation of the knee and support stability. They reduce the chance of hyperextension, and increase the agility and strength of the knee. The majority of these are made of elastic. They are the least expensive of all braces and are easily found in a variety of sizes.

Rehabilitation braces are used to limit the movement of the knee in both medial and lateral directions- these braces often have an adjustable range of motion stop potential for limiting flexion and extension following ACL reconstruction. They are primarily used after injury or surgery to immobilize the leg. They are larger in size than other braces, due to their function.