Orthotic Prescription

The prescription for an orthosis is an essential part of the larger process of rehabilitation to improve patient function and promote participation in life activities. Each member of the interdisciplinary team offers expertise that allows the team to work collaboratively with the patient to identify goals for orthotic intervention and shared rehabilitation goals.

An effective interdisciplinary approach fosters communication by involving all team members throughout the treatment process. A collaborative clinical environment allows team members the opportunity to clarify their clinical recommendations and educate other team members on their areas of expertise. Because of current health care policy and financial demands, this interdisciplinary approach may be possible in the acute setting but is typically challenging to achieve in outpatient settings. This lack of face-to-face communication requires the use of detailed documentation notes by the physician and others to convey the assessment findings and clinical reasoning.

Formulation of the orthotic prescription begins with the physician's medical evaluation of the patient, identification of the pathology and associated functional impairments, and prognosis. The assessment of the individual consists of a history that includes problems noted by the patient, prior interventions, and patient expectations and goals. The identification of patient-related and environmental factors as outlined by the World Health Organization's conceptual framework, the International Classification of Functioning, Disability, and Health (also known as the ICF) provides insight into how an individual functions in daily life. This context is key to informing the orthotic treatment plan.

Determining the appropriate orthotic prescription is grounded in the biomechanical needs of the patient as identified through a physical evaluation that includes manual muscle testing (MMT), range-of-motion (ROM) testing, and sensory testing. Through the integration of the biomechanical needs and the personal and environmental factors of the individual, the optimal orthosis design is identified. Although the actual prescription for an orthosis communicates the type of device recommended to meet the biomechanical and functional needs of the patient, the physician's clinic documentation note contains the necessary information justifying the (1) need for a custom-fabricated orthosis rather than a custom-fitted orthosis, (2) need for long-term use of the orthosis, and (3) planes of static and dynamic control necessary at each joint (sagittal, coronal, transverse).

In addition, the physician considers additional referrals necessary to support the comprehensive orthotic treatment plan. This may include supporting therapies, medications, surgeries, or injections to improve the underlying condition before provision of an orthosis or to improve the outcomes of the intervention. For example, an individual with a knee flexion contracture and quadriceps weakness may be referred to physical therapy in an attempt to reduce the contracture before orthotic intervention. Reducing the knee flexion contracture will improve the effective use of a ground-reaction ankle-foot orthosis (AFO) by increasing the external knee extension moment created by the AFO from midstance to terminal stance.

The interdisciplinary team is most effective when team members work cooperatively, sharing perspectives and expertise and effecting a blend of the physician's medical knowledge; the orthotist's understanding of biomechanics, design, and material options; and the occupational and physical therapists' evaluation of functional abilities, education, and therapy to improve function.

Follow-up is crucial to assess the functional outcome and success of the orthotic treatment plan in meeting the patient's goals and the patient-centered rehabilitation team goals. Functional outcomes may be patient reported or performance based to assess improved quality of life, mobility, self-care, or other constructs of value specific to each individual. The Activities-Specific Balance Confidence (ABC) Scale is an example of a self-report measure used to assess an individual's level of confidence while involved in specific activities such as walking up or down stairs, in crowds, or on icy sidewalks. The Timed Up and Go (TUG) is a commonly used performance measure assessing balance, functional mobility, gait, and potential risk for falls. The routine integration of outcome measures into the orthotic treatment plan has the potential to provide increased knowledge regarding the success of the orthotic prescription in achieving the desired improvement in patient function and increased participation in life activities.

Terminology

An orthosis or orthotic device is an appliance applied to the body to stabilize or immobilize a body part, improve alignment, prevent deformities, protect against injury, or assist with motion or function. The term orthotics refers to the science and practice of assessment, fabrication, fitting, and adjusting of an orthosis.

Orthoses are described by the standards agreed upon by the International Organization for Standardization (ISO), an independent, nongovernmental organization with global representation on each technical committee. All orthoses should be designated using ISO acronyms according to the joints or body segments involved, such as AFO for ankle–foot orthosis ( Fig. 1.1 ) or WHO for wrist–hand orthosis ( Fig. 1.2 ). To generate an appropriate prescription, it is crucial to use the accepted terminology.

The prescription specifies whether the orthosis is (1) prefabricated and off-the-shelf, (2) prefabricated and custom fitted, or (3) custom fabricated. A prefabricated orthosis is considered off-the-shelf if specialized training is not required to complete “minimal self-adjustments” at the time of fitting (e.g., strap and closure adjustment). A prefabricated orthosis requiring substantial modifications at the time of fitting by a qualified practitioner is considered custom fitted. A custom-fabricated orthosis is made for a specific individual from a positive model of the person obtained through casting, measurements, tracing, or an image.

Inclusion of specific biomechanical characteristics describing the orthosis is essential. Examples of these features include design characteristics regarding materials (e.g., thermoplastic, carbon), knee joints (e.g., drop locks, free knee, bale lock), and biomechanical controls at the ankle joint (dorsiflexion or plantarflexion assistance or resistance) ( Fig. 1.3 ).

Ankle Joint Controls and Their Function

Other general descriptive terms, such as static, dynamic, and progressive, provide clarification of the goals for the orthosis ( Table 1.1 ). The term static implies that there is no motion across the joint or segment involved, with stabilization as the primary goal. A static thermoplastic WHO (see Fig. 1.2 ) allows no motion at the wrist and may provide positioning to protect the wrist joint. A dynamic orthosis indicates there is motion across the joint. A wrist-driven WHO is a dynamic orthosis capturing the movement of wrist extension to provide a palmar prehension grasp ( Fig. 1.4 ). To accommodate the reduction of a plantarflexion contracture through a stretching program, a progressive AFO design ( Fig. 1.5 ) incorporates an adjustable ankle joint matches the individual's changing position.

TABLE 1.1

Ankle Joint Controls and Their Function

Angle Joint Control	Function
Free motion	Allows free range of motion in the sagittal plane while controlling coronal plane motion
Fixed position	Fixed position in the sagittal plane
Limited motion	Allows controlled sagittal plane range of motion
Plantarflexion stop	Compensates for dorsiflexion weakness by limiting plantarflexion range of motion
Dorsiflexion assist	Compensates for dorsiflexion weakness by assisting dorsiflexion range of motion
Dorsiflexion stop	Compensates for plantarflexion weakness by limiting dorsiflexion range of motion from midstance to terminal stance