Rheumatoid arthritis (RA)
Upon completion of this chapter, you will be able to:
1. Describe the clinical conditions and goals for fabrication of a wrist immobilization orthosis.
2. Identify pertinent anatomical structures and biomechanical principles involved in a wrist immobilization orthosis and apply these concepts to orthotic design and fabrication.
3. Identify the four most commonly selected orthoses designs and describe the rationale for choosing one design over another.
4. Design suitable patterns for the four common types of wrist immobilization orthoses and identify the pertinent anatomical landmarks.
5. After reviewing the instructional videos:
a. Outline the steps involved in the fabrication of a wrist immobilization orthosis.
b. Complete the molding and finishing of a wrist immobilization orthosis.
c. Evaluate the fit and function of a completed wrist immobilization orthosis and identify and address all areas needing adjustment.
6. Identify elements of a client education program following fabrication of a wrist immobilization orthosis.
7. Describe special considerations of wrist orthotic design and fabrication for special populations.
Box 4-1. Common Goals of Wrist Immobilization Orthoses
- Support and protect the wrist following surgical repair of structures.
- Support and protect the wrist after a fracture or ligament injury.
- Offer relief and joint protection from a painful tendinitis or arthritis.
- Position the wrist to prevent prolonged wrist flexion posturing that can compress the median nerve.
- Position the wrist to prevent shortening of muscles and tendon(s) due to changes in muscle tone.
- Support and position the wrist in slight extension to improve grasp and release hand function due to muscle paralysis or weakness.
- Use the orthosis as a base for outrigger attachments to create mobilization orthoses and/or adaptive equipment.
The wrist is the cornerstone of the hand. It serves to balance muscle forces, promote anatomical alignment of the hand skeleton, and facilitate optimal grip and prehensile function. Proper wrist positioning and stability is critical for optimal hand function. Ten to 40 degrees of wrist extension allows the fingers and thumb to move freely and provides balance to the forearm extrinsic flexor and extensor muscles. Wrist immobilization orthoses offer support for injured bones, tendons, nerves, joints, ligaments, and other soft tissues crossing the wrist. These orthoses are used as a therapeutic intervention for a wide variety of upper extremity conditions and are common orthoses that practitioners provide for their clients.
When properly fabricated and fitted, wrist immobilization orthoses stabilize the wrist joint and allow full movement of the fingers and thumb, thereby enabling clients to perform light functional tasks without difficulty. There are several different wrist design options. The design chosen will depend on multiple factors, including the client’s clinical condition, his or her functional needs, and specifications set by the referring physician.
Goals for Use of a Wrist Immobilization Orthosis
When fabricating a wrist immobilization orthosis, the practitioner must do the following:
- Be knowledgeable regarding the specific clinical condition or diagnosis
- Be knowledgeable about the expected clinical outcome following orthotic use
- Be aware of the goal(s) of the orthosis
- Use sound clinical reasoning to select the most appropriate design
The goals of a wrist immobilization orthosis will vary depending on the individual client’s needs and clinical condition (Box 4-1).
Clinical Conditions and Wearing Schedules
The following section describes several clinical conditions commonly seen by practitioners where a wrist immobilization orthosis may be prescribed. Readers are encouraged to review the anatomy and biomechanical principles presented in Chapter 2 and the suggested reading provided for additional details regarding each clinical condition. Current evidence supporting wrist orthoses as an intervention strategy for each clinical condition is provided when available.
CARPAL TUNNEL SYNDROME
Carpal tunnel syndrome is the most common form of peripheral nerve compression in the upper extremity. In this condition, the median nerve becomes compressed within a narrow tunnel in the proximal palm that is formed by the carpal bones and covered by the transverse carpal ligament (Figure 4-1). In addition to the median nerve, nine tendons are enclosed in this tunnel (four slips of the flexor digitorum superficialis, four slips of the flexor digitorum profundus, and the flexor pollicis longus).
A number of factors can account for compression of the median nerve in this small tunnel, including the following:
- Swelling of the synovial tissues surrounding any of the nine tendons inside the carpal tunnel, a disease process such as rheumatoid arthritis (RA), and/or diabetes
- Prolonged positioning of the wrist in flexion, which decreases the available space for the contents of the carpal tunnel to move freely
- Altered wrist anatomy from an injury such as a carpal bone or distal radius fracture
- Lumbrical muscles entering the carpal tunnel during full finger flexion
- Constant repetitive wrist motion causing friction between the flexor tendons and the flexor tendon sheaths causing inflammation within the carpal tunnel
All of these factors, plus additional health risk factors, may contribute to increased pressure on the median nerve and cause complaints of numbness and tingling in the thumb, index and long fingers, and radial half of the ring finger; aching and pain; and weakness with pinching and gripping tasks.
A wrist orthosis positioning the wrist in 0 to 15 degrees of extension can minimize compression of the median nerve by preventing a prolonged flexed posture of the wrist and reducing repetitive movement of the tendons in the carpal tunnel, allowing all inflamed structures to rest and heal. Clients may need further evaluation of symptoms, which may be aggravated by strong grasping motions. An orthosis that includes the metacarpophalangeal (MCP) joints can minimize movement of the lumbrical muscles into the carpal tunnel and reduce compression of the median nerve during repetitive grasping activities. Please refer to additional sources for information on contributing health risk factors for carpal tunnel syndrome.
Depending on the severity of the client’s symptoms, the wearing schedule for the client presenting with carpal tunnel symptoms may be full-time until numbness, tingling, and pain are resolved. Nighttime use is often prescribed for clients who have severe symptoms at night, causing them to waken with complete numbness in the affected fingers. Other clients might benefit from wearing the orthosis during activities that aggravate the symptoms. There is no one correct wearing schedule. Each client should be evaluated and prescribed an individualized wearing schedule that helps relieve his or her specific symptoms.
- Huisstede, B. M., Fridén, J., Coert, J. H., Hoogvliet, P., & European HANDGUIDE Group. (2014). Carpal tunnel syndrome: Hand surgeons, hand therapists, and physical medicine and rehabilitation physicians agree on a multidisciplinary treatment guideline—Results from the European HANDGUIDE study. Archives of Physical Medicine and Rehabilitation, 95(12), 2254-2264.
- The authors describe a Delphi consensus strategy where expert surgeons, physicians, and therapists meet and agree on the description, symptoms, and diagnosis of carpal tunnel syndrome and discuss the effectiveness of surgical and nonsurgical interventions. The experts agreed that patients with carpal tunnel syndrome should first be given home instructions to avoid certain wrist postures, instructions combined with splinting, corticosteroid injection, corticosteroid injections plus splinting, and, finally, surgery to alleviate symptoms. A relationship between the severity/duration and choice of therapy was found by the experts and reported in the guideline.
- Page, M. J., Massy-Westropp, N., O’Connor D., & Pitt V. (2012). Splinting for carpal tunnel syndrome. Cochrane Database of Systematic Reviews, 7, CD010004. doi:10.1002/14651858.CD010004
- This systematic review examined the effectiveness of splinting for mild to moderate carpal tunnel syndrome compared with no other treatment, with a placebo, and with other nonsurgical interventions. Of the 19 studies included in this systematic review, most were of low quality with the risk of bias. It is difficult to determine from the evidence whether one splint design or wearing schedule is more effective than another, or if splinting is more effective than other nonsurgical interventions for carpal tunnel syndrome (e.g., exercises and oral steroids). The authors concluded that more research is needed to find out how effective and safe splinting is for people with carpal tunnel syndrome, particularly in the long term.
- Bardak, A. N., Alp, M., Erhan, B., Paker, N., Kaya, B., & Önal, A. E. (2009). Evaluation of the clinical efficacy of conservative treatment in the management of carpal tunnel syndrome. Advances in Therapy, 26(1), 107-116.
- This study compared tendon and nerve-gliding exercises with splinting and injections in patients with carpal tunnel syndrome. A total of 111 patients with carpal tunnel syndrome were randomized into three treatment groups looking at different combinations of the above protocols. All patients reported improved symptoms after treatment, but patients receiving injections and splinting and tendon and nerve-gliding exercises (or without the additional exercises) improved better than patients performing only tendon and nerve-gliding exercises. The splint provided positioned the wrist in a neutral position and was worn for 3 weeks initially full-time, then at night only for the additional 4 weeks of the testing period.
- Celik, B., Paker, N., Celik, E. C., Bugdayci, D. S., Ones, K., & Ince, N. (2015). The effects of orthotic intervention on nerve conduction and functional outcome in carpal tunnel syndrome: A prospective follow-up study. Journal of Hand Therapy, 28(1), 44-48. doi:10.1016/jht.2014.07.008
- These authors conducted a prospective comparative study examining the effectiveness of wearing a wrist immobilization orthosis for 6 consecutive weeks in treatment for mild to moderate carpal tunnel syndrome. Electromyography (EMG) studies and other outcome measures sensitive to carpal tunnel intervention were used. Results indicated improvement in EMG findings with orthotic use after 6 weeks, with no significant change in other outcome measures. The authors note that changes in EMG findings may be more sensitive than carpal tunnel syndrome outcome questionnaires. This study supports use of wrist orthoses for mild to moderate carpal tunnel syndrome.
A wrist sprain is an injury to the ligaments in the wrist that connect the carpus to the forearm bones. Ligaments are especially important in maintaining the joint space between the carpal bones (arranged in proximal and distal rows) and the radius and ulna. Sprains can be classified as mild when ligaments are stretched or severe when ligaments are completely torn. Torn ligaments can lead to carpal bone instability, a common source of pain and decreased hand function. A wrist orthosis can help maintain the ligaments in their optimal position and alignment to facilitate healing and allow the client to use his or her injured hand for light activities of daily living (ADL).
A client presenting with pain due to a ligament sprain or tear should wear a wrist immobilization orthosis full-time in order to alleviate symptoms and allow for healing of the injured structures, or as directed by the referring physician. More severe injuries may require surgical intervention. Wrist orthoses may be used following surgery to protect the repaired structures, optimize healing, and facilitate light use of the injured hand.
There is a lack of current research to support the use of an orthosis with wrist sprains. However, the following two studies are cited.
- Rønning, R., Rønning, I., Gerner, T., & Engebretsen, L. (2001). The efficacy of wrist protectors in preventing snowboarding injuries. American Journal of Sports Medicine, 29(5), 581-585.
- These authors conducted a randomized clinical trial of 5029 snowboarders to investigate the effect of wearing a wrist support during the activity to see if it was helpful at preventing injury. A total of 2515 participants of the study received a wrist support, and 2514 did not. The primary endpoint was fracture or sprain of the wrist with loss of range of motion (ROM) and pain of at least a 4-day duration. Eight wrist injuries occurred in the braced group, and 29 occurred in the control group. The wrist support used in the study was a commercially available wrist wrap with D-ring strapping and a volar-based formable aluminum support. The authors conclude that a wrist support can help prevent wrist injuries in a high-impact sport such as snowboarding, but they also determined that the support used in this study may have been too soft to absorb the necessary amount of energy to reduce the number of injuries of the wrist.
- Prosser, R., Herbert, R., & LaStayo, P. C. (2007). Current practice in the diagnosis and treatment of carpal instability: Results of a survey of Australian hand therapists. Journal of Hand Therapy, 20(4), 249-242.
- The authors surveyed hand therapists in Australia regarding the treatment of carpal instabilities. Although patients with this diagnosis often have full ROM, functional ADL may be affected due to pain and decreased grip strength. Respondents reported that patient education and wrist splinting were the most commonly provided treatments. Use of wrist orthoses may help decrease pain and motion, contributing to healing and stability. Although this is a Level V paper and only reports the results of a survey, it does indicate current practice patterns and the use of orthoses as a therapeutic intervention.
Fracture of any of the carpal bones (except the scaphoid, which typically requires immobilization of the wrist and first metacarpal bone) or the radius or ulna bones may be designated a wrist fracture, although the most commonly injured bone is the distal radius (Figure 4-2). Some wrist fractures may be treated with surgery involving volar or dorsal plating, external fixation, and/or K-wires; others are treated with immobilization using plaster casts or immobilized with the use of a removable orthosis. Often, after surgery or after the cast or external fixator has been removed, a wrist orthosis may be fabricated to support and position the healing structures and to allow the client to begin active wrist ROM, exercises, and light use of the injured hand.
Following surgical procedures to stabilize a wrist fracture, a wrist orthosis may be used to protect and support healing structures. Clients should be instructed to wear the wrist immobilization orthosis full-time, except for exercises and hygiene for several weeks. Full healing of the bony structures will indicate when it is safe to discharge the orthosis. Nighttime wear and use during activities may continue for several additional weeks as an extra precaution.
- Bong, M. R., Egol, K. A., Leibman, M., & Koval, K. J. (2006). A comparison of immediate post reduction splinting constructs for controlling initial displacement of fractures of the distal radius: A prospective randomized study of long-arm versus short-arm splinting. Journal of Hand Surgery, 41(5), 766-770.
- These authors conducted a prospective, randomized, controlled trial comparing use of a plaster, long-arm, sugar tong splint and a short-arm, radial gutter splint in maintaining reduction following displaced distal radius fractures. Results indicated that both splints were effective at maintaining the initial fracture reduction, but patients in the short-arm group had significantly higher Disabilities of the Arm, Shoulder and Hand scores. This study used plaster splints in both groups, but findings support use of wrist immobilization orthoses/splints over long-arm orthoses for initial management of displaced distal radius fractures.
- Williams, K. G., Smith, G., Luhmann, S. J., Mao, J., Gunn, J. D., & Luhmann, J. D. (2014). A randomized controlled trial of cast versus splint for distal radial buckle fracture. Pediatric Emergency Care, 29(5), 555-559.
- The authors conducted a randomized, controlled trial comparing casting verses splinting to treat distal radial buckle fractures in patients aged 2 to 17 years. Outcomes measured were parental and patient satisfaction, preference, convenience, and pain. Results support use of wrist splints for all variables except pain. Pain was higher in the splint group, but results were not statistically significant. This study supports use of wrist orthoses for management of distal radial buckle fractures in the pediatric population.
Wrist tendinitis is a common condition caused by inflammation or irritation of any one or more of the tendons crossing the wrist (extensor carpi radialis longus, extensor carpi radialis brevis, extensor carpi ulnaris, flexor carpi radialis, or the flexor carpi ulnaris). The flexor digitorum superficialis and flexor digitorum profundus tendons may also be involved. The site of inflammation and pain may also arise from the involved muscle’s origin at the elbow (medial and/or lateral epicondyle) and can be more pronounced with gripping tasks and wrist movement (Figure 4-3). A wrist orthosis can help maintain the wrist in a specific position to allow rest of the involved tendons and facilitate continued use of the affected hand in functional tasks.
The orthosis is typically worn full-time initially to decrease symptoms. Tendinitis of the wrist muscles may take up to 6 weeks to resolve with rest and reduced activities, including immobilizing the involved tendon(s) in a wrist immobilization orthosis that limits or reduces strain on the tendon insertion site. For example, a wrist orthosis for treatment of tendinitis of the flexor carpi radialis tendon may be positioned in 10 degrees of flexion.
- Garg, R. G., Adamson, G. J., Dawson, P. A., Shankwiler, J. A., & Pink, M. M. (2010). A prospective randomized study comparing a forearm strap brace versus a wrist splint for the treatment of lateral epicondylitis. Journal of Shoulder and Elbow Surgery, 19(4), 508-512.
- The authors conducted a prospective randomized, controlled trial comparing the effectiveness of a wrist immobilization orthosis and a forearm counterforce brace for management of acute lateral epicondylitis. Pain was significantly less with use of the wrist orthosis, but both interventions were similar in all other clinical outcomes.
Both osteoarthritis (OA) and RA can affect the wrist with decreased motion, pain, and weakness (Figure 4-4).
RA is an autoimmune disease that typically affects the wrist and small joints in the hand and often occurs on both sides of the body. The synovial tissue within joints and surrounding tendon sheaths is targeted by the body’s immune system and can cause significant joint dysfunction (Table 4-1).
In contrast, OA is a wear-and-tear degenerative condition where the cartilage lining the articular joint surfaces is affected by repeated stress on the joints as a client ages or by past injury to the articulating surface(s) of the joint. The larger weightbearing joints, along with the shoulder, elbow, wrist, and small finger and thumb joints, are most commonly affected. OA can affect only one joint in the body, but it is more common to have the condition on both sides (see Table 4-1). A wrist orthosis can help with both RA and OA symptoms by supporting the wrist in a resting and comfortable position to reduce pain, facilitate grasp, release hand function, improve grip strength, and protect the wrist joints during ADL tasks.
Wearing Schedule for Rheumatoid Arthritis
Orthotic intervention for clients with RA can help with positioning, pain relief, and functional assistance. Depending on the individual needs of the client, orthoses can be worn full-time or on an as-needed basis to assist with specific tasks and activities. Clients with RA benefit from lightweight materials and noncumbersome designs. Specific attention should be paid to the strapping materials used to avoid pressure points and to make sure each client has adequate pinch strength to pull the straps open and to close them. Additionally, it is important for the practitioner to be aware that immobilizing the wrist can place more stress on the MCP, proximal interphalangeal, and distal interphalangeal joints during hand use. Including the MCP joints may help if this is a concern.
Wearing Schedule for Osteoarthritis
Orthoses provide pain relief and support to joints affected by OA. Clients should be encouraged to wear these orthoses as needed for symptom reduction and assistance with ADL. Initially, full-time use of the wrist orthosis may reduce symptoms of pain enough to allow for a gradual decrease of orthotic use over time.
- Valdes, K., & Marik, T. (2010). A systematic review of conservative interventions for osteoarthritis of the hand. Journal of Hand Therapy, 24(4), 444-451.
- The authors conducted a systematic review looking at conservative treatments for the management of hand OA. Orthoses are a common intervention and cited in 11 of the 21 studies included in this review. The authors conclude that there is high to moderate evidence to support the use of wrist orthoses for this population.
- Egan, M., Brosseau, L., Farmer, M., Ouimet, M. A., Rees, S., Tugwell, P., & Wells, G. (2001). Splints and orthosis for treating rheumatoid arthritis. Cochrane Database of Systematic Reviews, 4, 1-26.
- The authors sought to determine the effectiveness of splints/orthoses in relieving pain, decreasing swelling, and/or preventing deformity and to determine the effect of splints/orthoses on strength, mobility, and function in people with RA. They reviewed a total of 10 papers reporting on the use of working wrist splints (5), resting hand and wrist splints (2), and special shoes and insoles (4). They report that there is evidence that wearing wrist splints during work decreases grip strength and does not affect pain, morning stiffness, pinch grip, or quality of life after up to 6 months of regular wear. In addition, no evidence was found to suggest that resting wrist and hand splints change pain, grip strength, or number of swollen joints. However, participants reported that they preferred the use of orthoses to nonuse, and padded resting splints to unpadded ones. There is insufficient evidence to make firm conclusions about the effectiveness of working wrist splints in decreasing pain or increasing function for people with RA. Potential adverse effects, such as decreased ROM, do not seem to be an issue. Although resting hand and wrist splints do not seem to affect ROM or pain, participants report that they prefer wearing a resting splint to not wearing one.
In the absence of disease or injury, muscles have resting tone, or resistance to passive stretch. This is created by connective tissues present in muscle, as well as input from the central and peripheral nervous systems. A common physical impairment in the upper extremity following brain trauma or stroke is development of abnormal muscle tone. There are different terms used to describe abnormalities in tone. These include flaccidity, hypertonicity, hypotonicity, and rigidity. Flaccidity is characterized by absence of both muscle tone and deep tendon reflexes. No active movement in the extremity is observed. Flaccidity typically presents immediately following a traumatic injury or event in the brain or spinal cord. It can also occur following injury to a lower motor nerve or peripheral nerve. Hypertonicity typically develops a few weeks later but may also be present immediately following injury. In contrast to flaccidity, hypertonicity is an increase in muscle tone with resistance to active and passive movement. Injury to upper motor neurons in the brain or spinal cord interrupts the normal pathway between these neurons and the lower motor neurons. Stretch reflexes become hyperactive, resulting in increased muscle tone. In hypertonicity, changes can also occur in the connective tissue of the involved muscles and surrounding joints, resulting in soft tissue and/or joint contractures. Rigidity is also an increase in muscle tone, but muscles on both sides of a joint are affected, resulting in loss of voluntary movement in all directions that a joint moves. This is in contrast to hypertonicity, where muscle(s) on one side of a joint demonstrate increased tone, and muscle(s) on the other side become inactive, or weak. Hypotonicity, or less-than-normal muscle tone, is characterized by muscle weakness and impaired ability to resist the force of gravity during active movement. Wrist immobilization orthoses can help support hypotonic or flaccid muscles that cross the wrist to prevent overstretching, help prevent the development of joint stiffness and shortening of muscle fibers and tendons, and position the wrist for improved functioning of the fingers where there is some volitional muscle control.
Peripheral Nerve Injury
Following injury to one or more of the three peripheral nerves described hereafter, muscles that move the wrist and/or fingers can become paralyzed or weak due to loss of nerve impulses from the peripheral nerve to the muscle(s). Affected muscles have no or minimal muscle tone and lose their ability to contract normally to move joints. Figure 4-5A shows the classic wrist drop deformity associated with radial nerve palsy. Injury to the median and/or ulnar nerves can also create muscle imbalance across the wrist. Wrist orthoses can help support weak or paralyzed muscles, help to rebalance muscle forces across the wrist to improve finger and thumb function, and prevent overstretching or shortening of affected muscles. This is especially important for injuries involving the radial nerve where the wrist extensor muscles cannot contract strongly enough against the force of gravity to extend the wrist, creating significant muscle imbalance and loss of grip and prehensile function (Figure 4-5B). The wrist orthosis may also be used as a base for outriggers use in dynamic mobilization orthoses for radial nerve palsy. This advanced type of orthosis will be addressed in Chapter 10.