Getting Started

Perusing published literature regarding orthotic theory and application can be daunting, especially for therapists who are inexperienced in fabricating orthoses. However, it is important to remember that each “experienced” therapist had to begin by making his/her first orthosis. Orthotic fabrication is a skill that is developed through experience and over time. It is not an inherited trait. Practice is imperative. Being familiar with materials and understanding basic anatomy, kinesiology, and biomechanical concepts are the keys to success. As with all new skills, orthotic proficiency involves a crucial learning curve. Those who do not take the time to prepare, never learn. Conversely, those who persevere in developing their skills through practice and application, become increasingly adept. Upgrading skills and knowledge is also important as new materials and concepts are introduced.

Historical Perspective¹

Application of orthoses is not a contemporary concept. Leaves, reeds, bamboo, and bark with linen padding were used to immobilize fractures in early antiquity. By the 1500s, copper orthoses augmented treatment of individuals with burn injuries; and Hippocrates applied orthoses to either immobilize or distract fractures (460-377 bc). Created by armor-makers, turn-buckle orthoses were used to correct joint contractures by 1517; and surgeons worked with “appliance-makers” to create custom orthoses from the 1750s to the 1850s. Plaster of Paris became a popular orthotic material in the mid-1850s; and the first book dedicated to describing orthoses was published in 1888. The era of surgeon-fabricated orthoses began in the late 1800s, continuing well into the 20th century. From early to late 20th century, eight major factors influenced orthotic practice, including (1) disease; (2) political conflict/war; (3) surgical advances; (4) commercial products; (5) basic science advances; (6) governmental agency support; (7) creation of specialized hand centers; (8) knowledge dissemination and organizational leadership. The consequences of epidemiologic disease (for example, infection, polio) and war injuries provided momentum to surgical and basic science advances (for example, anatomy, wound healing, tissue remodeling), eventually resulting in governmental support of early specialized hand/upper extremity, hospital-based treatment venues. Government agencies also supported dissemination of evolving knowledge through workshops and publications focused on teaching therapists about hand/upper extremity orthotic concepts and techniques. Concomitantly, material innovations facilitated orthotic fabrication, starting with aluminum (1920s) and moving through the “plastics revolution” (1930s to present). The race for space during the Cold War introduced even more sophisticated materials that were adapted by commercial entities for orthotic application. Based on Dr. Paul Band’s rehabilitation center in India, the first hand center in the United States (US) was established in 1961 in Chapel Hill, North Carolina. The 1970s were expansion years for hand surgeons and therapists. Surgeons began relying exclusively on therapists to provide orthoses and treatment for individuals in their care who had sustained upper extremity injuries; and cutting-edge specialty centers dedicated solely to treating upper extremity problems were established across the US. Professional hand specialty organizations for surgeons (American Society for Surgery of the Hand [ASSH], American Association for Hand Surgery [AAHS]) and therapists (American Society of Hand Therapists [ASHT], American Hand Therapy Foundation [AHTF], Hand Therapy Certification Commission [HTCC]) provided and continue to provide educational and research forums relating to orthotic intervention for the upper extremity; and the Journal of Hand Surgery and the Journal of Hand Therapy disseminate up-to-the-minute orthotic concepts. While books and manuals relating to upper extremity orthoses reached their pinnacle in the 1980s, production of orthotic-specific publications continue to the present.

Makers of Orthoses

Although their respective areas of expertise differ, currently, both therapists (occupational therapists and physical therapists) and orthotists create and apply orthotic devices. Traditionally, therapists work closely with hand/upper extremity surgeons to fabricate orthotic devices that most often require application during early- to mid-treatment intervention. These orthoses routinely necessitate frequent adjustments and alterations in order to keep up with clients’ changing medical requirements; and are usually constructed from less durable materials, such as thermoplastics, or even plaster of Paris. In contrast, orthotists traditionally work with orthotic materials that are more durable in order to achieve the requisites of clients that are well past their immediate remedial needs.

Rationale for Orthotic Application

Reasons for orthotic intervention directly correlate with injury-specific and/or disease-specific patient diagnoses. In a review of published literature spanning over a fifty-year time frame, twenty-seven different rationales for orthotic intervention were identified; with the six most frequently cited reasons, listed in rank-order, including to (1) increase function; (2) prevent deformity; (3) correct deformity; (4) protect healing structures; (5) restrict motion; and (6) allow tissue growth/remodeling.¹

Design

Although orthotic devices often are crucial “door-openers” for subsequent referrals, they are never regarded as stand-alone interventions. Instead, each orthosis is created to reflect individual contextual conditions of why the orthosis is needed and how it will be used to help return the person for whom it was created to an active participatory lifestyle. Like a carefully choreographed dance, the tempo of which is dictated by wound healing status, therapists create and modify orthoses in accordance with a multitude of client variables including, but not limited to, diagnosis, wound status, concomitant exercise programs, physical and mental status, age, motivation, intelligence, activities of daily living (ADLs), instrumental activities of daily living (IADL), work, family support, distance from the clinic, etc. Unfortunately, client third-party payer status sometimes must also be part of these considered factors. Meeting individual needs requires therapist creativity and understanding of the ramifications of design options. Even if two clients have similar diagnoses, their resulting orthoses may differ due to their respective individual circumstances.

In addition to satisfying client-specific requisites, orthoses absolutely must function properly. In other words, they must accomplish, in the most efficacious manner possible, the purposes for which they are applied. Otherwise, they limit the rehabilitation potential of those who wear them.

Materials and Equipment

As noted in the “Historical Perspective” section, orthotic materials evolve as technology becomes more sophisticated. Chemical composition differentiates physical properties of thermoplastic materials. Both high and low temperature thermoplastics become malleable through heat application. Most thermoplastics used in clinical situations are low temperature materials; although some high temperature thermoplastics are used for outrigger components or as reinforcement for weaker materials. While more uniform levels of heat transfer are achieved via wet heat, the majority of thermoplastic materials currently available to therapists may be warmed using either wet or dry heat. Thermoplastic materials are often described by their “draping” capacity. Some materials require a given amount of finger pressure to mold them to an extremity, while others simply drape or “flow” themselves onto and into extremity contours. Each material has advantages and disadvantages. Astute therapists coordinate material physical properties to meet the needs of their individual clients.

Companies that supply orthotic materials encourage therapists to familiarize themselves with a wide range of orthotic products by making available at no cost or minimal cost, “sample kits” of orthotic materials. In addition to thermoplastic materials, do not dismiss the conforming advantages of plaster of Paris. This material continues to hold a special place in orthotic fabrication, especially for orthoses created to mobilize joints via application of orthoses that are changed serially.

Basic equipment for fabricating orthoses includes, but is not limited to, a water heat pan, several pairs of sharp scissors, a heat gun, a rotary hole-punch, box cutter, wire cutters, an awl, and a goniometer (Fig. 7-2). Scissors that are used for cutting Velcro should be segregated and used only for this task since they tend

Clinical Pearl

Limiting oneself to just one thermoplastic material considerably narrows ones’ ability to provide optimal therapeutic intervention for clients. Practicing with new materials as they are introduced to the market is essential for both novice and experienced therapists (Fig. 7-1).

Ergonomic use of tools and equipment is essential to producing orthoses that are professionally assembled and finished. Simple practices, like rounding orthotic corners and strap-end eliminates uncomfortable pointed ends and edges (Fig. 7-3).

Additionally, improper use of equipment may injure the hands of those who fabricate orthoses. When cutting materials, therapists should keep their hands and wrists in neutral postures and bring materials to the scissors to avoid “chasing” the material, which increases exposure to risk factors associated with awkward postures. Over time, therapists who ignore ergonomic concepts while fabricating orthoses tend to develop finger and thumb joint pain from stress and overuse injuries. For example, commonly seen thumb carpometacarpal (CMC) and/or metacarpophalangeal (MP) joint pain often stems from the chronic practice of cutting under-heated thermoplastic materials.

Factors That Allow Orthoses to Work Effectively

In mechanical terms, orthoses function either as lever systems that apply three-point pressures in reciprocal patterns (Fig. 7-4); or they apply two-point pressures in opposing patterns (Fig. 7-5). The vast majority of orthotic designs utilize three-point pressures. Although less frequently used, the most common reasons for applying two-point pressure orthoses are to support stable fractures (for example, humerus; metacarpals) or to support healing/repaired pulleys of digital flexor tendons.

See Table 7-1 for mechanical principles for creating effective orthoses.²

TABLE 7-1

Mechanical Principles of Orthotic Fabrication and Fit

Principle	Implication
1. Understanding force systems	Know when to use three-point pressure orthotic designs and when to use two-point pressure orthotic designs.
2. Increase the area of force application	Wider orthotic components decrease pressure and increase comfort.
3. Increase mechanical advantage	Longer orthotic components decrease pressure and increase comfort.
4. Use optimum rotational force	Application of corrective force is most efficient at a 90-degree angle.
5. Consider torque effect	The further away from the main focus joint a force is applied, the greater the torque on that joint will be. Be careful to not exceed tissue and/or pain thresholds.
6. Control reaction at secondary joints	Prevent subluxation of joints proximal and/or distal to primary focus joints within longitudinal rays.
7. Consider reciprocal parallel force effect	• Middle reciprocal pressure in a three-point pressure orthosis equals the sum of proximal and distal forces. • Monitor the area under middle-reciprocal-pressure components carefully for soft tissue breakdown. Only gold members can continue reading. Log In or Register to continue Share this: Click to share on Twitter (Opens in new window) Click to share on Facebook (Opens in new window) Related Related posts: Some Thoughts on Professionalism Perspectives on Pain Tissue-Specific Exercises for the Upper Extremity Burns Flexor Tendon Injury Peripheral Nerve Problems Stay updated, free articles. Join our Telegram channel Join Tags: Fundamentals of Hand Therapy Clinical Reasoning and Treatment Gu Sep 9, 2016 | Posted by admin in MANUAL THERAPIST | Comments Off on Orthoses: Essential Concepts Full access? Get Clinical Tree Get Clinical Tree app for offline access Get Clinical Tree app for offline access