• Trusted by the NHS, Doctors and Clinicians
  • Over 1 Million Braces Sold Worldwide
  • Free Standard Delivery on all UK orders
  • Free Returns on all Orders

The top terms an orthotist uses (and what they mean)

Orthotics is an area of medicine that is concerned with the design, provision and use of artificial devices called orthoses. There are various types of orthoses, such as splints or braces, and these are used on different parts of the body to improve function, correct disability or deformity, and provide external support to weak or abnormal muscles or joints. Clinicians who work in orthotics are called orthotists.

Orthotics is a branch of medicine that is rich with terminology that may be unfamiliar to many of us. Here are some of the key terms or phrases you might hear orthotists use, and what they mean.

Orthosis / orthoses

Both orthosis and orthoses mean the same thing, with orthosis being in the singular, and orthoses in the plural. This term is probably one of the most common you will hear an orthotist use, and it relates to the devices used to treat a patient. Originating from the Greek word 'ortho', which means to straighten, orthoses help support and align specific parts of the body by using an external force. The goal of using orthoses is to strengthen weak muscles or joints, improve mobility and function, correct deformity, help with rehabilitation and reduce pain. Examples of orthoses include shoe inserts, neck or knee braces, wrist supports and splints. Patients may need to wear an orthosis for a number of reasons, including following an injury or trauma, having a specific medical condition or after surgery. In some cases, such as with shoe inserts, the orthosis can help to correct an abnormal walking pattern.

Orthosis classifications

Orthoses are often classified and abbreviated according to which part of the body they relate to.

AFO refers to an ankle foot orthosis (or ankle support), which covers the entire ankle to foot area. This type of orthosis is one of the most commonly used, and there are a lot of different types available to help tackle different problems. The AFO orthosis is also frequently known as the foot-drop brace.

When orthotists talk about KAFO, they are referring to a knee ankle foot orthosis. This is a long type of orthosis, extending from the knee to the foot.

In orthotics, another common term is a KO, or knee orthosis, also often known as a knee brace. A KO supports and aligns the knee, providing it with stability. It can be used to help a number of conditions, ranging from muscular impairment, to treating sports injuries and chronic illnesses like arthritis.

For problems of the back and spine, an orthotist might advise you to wear a TLSO, or thoraco-lumbo-sacral orthosis. This type of device fits under the arm and around the hips, ribcage and lower back, and is commonly used to treat curvature of the spine in scoliosis. It is also often used as part of rehabilitation therapy for those patients who have suffered a spinal fracture.

Form Fit Back Running

You might also hear an orthotist talking about an EO (elbow orthotic), SO (shoulder orthotic), HO (hip orthotic), DAFO (dorsal ankle foot orthotic) or an RAFO (pressure relief ankle foot orthotic). Different types of prosthetic devices are also abbreviated in this way.

Orthosis devices that are described as functional are normally used to control abnormal motion. These are commonly used to treat shin splints, tendinitis or foot pain. Orthotic devices that provide additional cushioning and support to functional orthoses, without aiming to align the joints, are known as accommodative orthoses. These tend to be softer and are used to treat diabetic foot ulcers and other painful foot conditions. Orthotists may also refer to soft orthoses, which are devices that are made from soft materials, such as elastic or fabric, and include cervical collars or a pressure gradient hose.


A brace is a common term used in orthotics to describe a type of orthosis that protects and supports a weakened or injured part of the body. Some braces are designed for short-term use, such as during the recovery of any injury, while others may be used over a long period of time to provide support from chronic conditions like osteoarthritis.

Braces work by offering support, but they can also play an active role in managing conditions and relieving symptoms of pain and inflammation. There are various types of braces that can be used on the knees, feet, ankles, elbows, neck, back or spine, for instance. Depending on which part of the body the brace is needed for, they can be made from plastic, metal, rubber or leather, and may be custom fitted or prefabricated.

Some braces are designed for a specific purpose, such as sports. Prophylactic braces, for instance, can help to prevent ligament tears, so are frequently used by athletes taking part in contact sports.

Female wearing a BioSkin knee skin running along a ridge overlooking a lake

A functional brace is generally used for knee injuries, to help improve the strength and mobility of the knee. These are designed in such a way to avoid hyperextension of the knee.

Braces that are used following surgery or treatment are known as rehabilitation braces, and their main function is to limit movement during the healing process. Anyone who has suffered an ACL (anterior cruciate ligament) injury of the knee that required surgical reconstruction may be required to wear a rehabilitation brace during the recovery period.

CAM Walker

If you have suffered a sprain to your foot or ankle, or this part of your body is recovering from surgery, your orthotist may advise you wear a CAM Walker. This controlled ankle motion device resembles a boot and it is worn on the foot to reduce pressure from the affected area and limit movements, while still allowing the patient to walk, aided by crutches.


A splint is another frequently used word in orthotics. Similar to a brace, a splint refers to a type of orthosis device that supports the body and helps to improve mobility, whilst reducing pain and inflammation. Splints can be used on various parts of the body, especially if there is a fracture, sprain or soft tissue injury.

Custom fitted and prefabricated orthoses

You may hear an orthotist talking about orthoses that are either custom fitted or prefabricated. Custom fitted orthoses are specially made to fit a specific patient, and the device used may be trimmed, shaped or bent to create an exact fit. If an orthosis is made to fit a particular patient, this may be done based on x-ray images, castings or measurements. When you hear the term prefabricated orthoses, this relates to those devices that are mass-produced or off-the-shelf, and don't normally require any alteration to fit a patient. There may be a variety of options and sizes of prefabricated orthoses.

Aaron Hadlow putting on his Custom CTi


The term suspension in orthotics relates to how an orthosis device is attached or held on. There are a number of options for this, including the use of a strap, belt or a neoprene sleeve.


When mechanical principles are applied to the movement of the body, this is known as biomechanics, and it is a term that is well known within the orthotic profession. A patient may be given an initial biomechanical assessment by an orthotist to assess what orthotic treatment is required. This typically involves a static assessment of the body, to determine if there are any abnormal joint positions and to test muscle strength. A dynamic assessment is also carried out to ascertain what the joint is like on movement and on bearing weight, and if there is any unusual gait. The word gait refers to a person's walking pattern, and it is a key term used in orthotic medicine.


Many people require treatment from an orthotist because they have problems with their feet. Lots of terms used in this branch of medicine, therefore, relate to the foot. Pronation is one such term that frequently gets used in orthotics, and this relates to the way the foot rolls inwards when you walk or run. This is a natural movement that is important for proper shock absorption. In cases where the foot rolls more than normal, this is known as over pronation, and it can cause excessive stress on the feet, leading to a variety of problems, including lower leg or knee pain. Orthoses can be helpful to alleviate this. Under pronation is where there has not been enough inward roll of the foot after landing, and is often associated with those people who have a high arch. It can cause stress fractures, shin splints and muscle strains, and can be prevented with the correct use of orthotic insoles.


Orthotics and prosthetics are closely related in medical terms and share some similar characteristics, but they have different functions. An orthotic device helps to enhance or support a limb, while a prosthetic device replaces the limb completely. Orthotics and prosthetics are often used by people who experience similar conditions or illnesses. Devices used in orthotics and prosthetics are commonly made from the same materials, including nylon, plastic, kevlar, neoprene rubber and lightweight metals. A clinician working in prosthetics is known as a prosthetist.