An orthosis is an external medical device applied to the body to improve the function of the neuromuscular and skeletal systems. This device, commonly known as a brace or splint, is specifically engineered to modify the structural and functional characteristics of a body part. It is used to support, align, or correct a body segment that is weak, ineffective, or injured. The application of these devices is a specialized medical field known as orthotics, which aims to enhance mobility and quality of life for individuals with various physical challenges.
The Core Function of Orthotic Devices
Orthoses operate on biomechanical principles to achieve several primary therapeutic goals. One fundamental function is stabilization, which involves immobilizing or limiting movement in a specific joint or body segment to promote healing after an injury or surgery. For instance, a knee brace may prevent excessive side-to-side motion, protecting a damaged ligament from further strain and allowing the tissue to repair itself.
These devices also play a role in correcting alignment and preventing the progression of physical deformities. By applying precise forces over a period of time, an orthosis can guide the growth or position of bones and joints, such as in the case of a spinal brace used to manage scoliosis. This continuous, gentle pressure works to maintain proper anatomical positioning, especially in growing children or individuals with chronic conditions.
A third major function is to assist movement or improve functional ability. An individual experiencing muscle weakness, such as foot drop due to nerve damage, may rely on an orthosis to lift the foot during the swing phase of walking. Furthermore, orthoses are frequently used to reduce pain by offloading weight or stress from an affected area. By redistributing pressure across a joint or limb, the device decreases the mechanical strain on damaged tissues, thus alleviating discomfort.
Common Categories Based on Application
Orthoses are categorized based on the specific anatomical region they are designed to support.
Lower Extremity Orthoses (LEOs)
Devices targeting the legs and feet are known as Lower Extremity Orthoses (LEOs), which range from simple shoe inserts to complex full-leg braces. A common example is the Ankle-Foot Orthosis (AFO), which spans the ankle and foot to control motion, often prescribed for neurological conditions that affect the ability to control foot movement. More extensive devices, such as Knee-Ankle-Foot Orthoses (KAFOs), are used when control is needed at the knee joint in addition to the ankle and foot.
Spinal Orthoses
The spine and trunk are managed by Spinal Orthoses, which are named according to the vertebral sections they encompass, such as a Thoracic-Lumbar-Sacral Orthosis (TLSO). These braces are designed to provide circumferential pressure to limit movement and support the spinal column. They are often used in the treatment of spinal fractures, post-surgical stabilization, or to manage conditions like idiopathic scoliosis by preventing the lateral curvature of the spine from worsening.
Upper Extremity Orthoses (UEOs)
Upper Extremity Orthoses (UEOs) focus on the shoulder, elbow, wrist, and hand. Wrist and hand splints are frequent examples, utilized to position the joints in a functional or resting posture. These devices may be used following a stroke to manage muscle tone, or after a fracture to immobilize the area and protect healing structures. UEOs can also help manage contractures, which are shortenings of muscles or tendons that restrict joint movement.
Distinguishing Orthoses from Prosthetic Devices
The terms orthosis and prosthesis are often confused, but they describe devices with fundamentally different purposes. An orthosis is designed to modify an existing body part, enhancing its function or protecting it from injury. It works with the body, supporting a limb or joint that is present but compromised. The goal is to maximize the utility of the existing biological structure.
A prosthetic device, conversely, serves to replace a body part that is missing due to trauma, disease, or a congenital condition. A prosthesis, such as an artificial limb, takes the place of the lost structure to restore both function and appearance. While both types of devices aim to improve a person’s mobility and quality of life, the orthosis modifies what is there, and the prosthesis substitutes what is not.
Obtaining, Customizing, and Maintaining Orthoses
The process of obtaining an orthosis begins with a medical evaluation, typically by a physician, who diagnoses the condition and prescribes the device. Following the prescription, the individual is referred to a certified orthotist, a specialist trained in the design, fabrication, and fitting of these devices. The orthotist performs a detailed assessment to determine the specific biomechanical goals of the treatment.
Orthoses can be either custom-made or prefabricated, known as off-the-shelf devices. Custom devices are fabricated from a mold or a 3D scan of the patient’s body part, ensuring an extremely precise fit necessary for complex conditions or long-term use. Prefabricated orthoses are mass-manufactured in standard sizes and are often used for less complex issues or short-term recovery, though they may still require adjustments by the orthotist.
Once the orthosis is ready, the orthotist conducts a fitting appointment to check for proper alignment, comfort, and function. The patient is provided with a wearing schedule, often involving a gradual break-in period to allow the skin and body to adjust to the device. Routine maintenance and follow-up are necessary to ensure the device remains effective and involves:
- Daily cleaning of the device.
- Regular skin checks to prevent irritation or pressure sores.
- Follow-up appointments to make adjustments and check for wear.