Musculoskeletal pain in the upper extremities can limit the activities of daily life in various ways [1]. With the recent advances in the development of electronic devices, as well as an increase in their accessibility, there has also been an increase in the number of complaints of pain in the wrists and fingers due to excessive use of devices such smartphones, mice, and keyboards in the same posture or for extended periods of time [2,3]. In addition, upper extremity pain is common in occupational groups that use their hands and arms [3,4]. Conditions that commonly cause upper extremity pain in the general population include tenosynovitis of the wrist and hand, carpal tunnel syndrome, osteoarthritis, epicondylitis of the elbow, and dislocation of the shoulder joint [5,6]. Symptoms include numbness, stinging, and tingling that can progress to severe pain to the extent of resulting in an inability to move [7,8]. To manage this pain, physical therapy, medication, corticosteroid injection, orthoses, and surgical treatment are mainly used [7]. In the initial stages, efforts are made to relieve symptoms through conservative treatment; however, if the symptoms are severe, surgical treatment is considered [7].

Orthoses are one of the most common tools for conservative therapeutic treatment in clinical practice. This study aimed to investigate the most commonly used orthoses and their effects on the control of upper extremity pain.

De Quervain's tenosynovitis is a disease that results in restricted movement and pain due to inflammation of the sheath surrounding the tendons of the abductor pollicis longus and extensor pollicis brevis [9]. It usually occurs due to excessive use of the wrist and thumb [10]. Symptoms include swelling, pain, or numbness in the thumb or wrist [9]. In addition, pain occurs when the tendon of the lateral wrist is pressed, when the wrist is moved, or when the thumb is flexed [10]. Conservative treatment includes medication, fixation using orthoses, extracorporeal shock wave therapy, and injection treatment [11,12]. Surgical treatment is considered when conservative treatment proves to be ineffective [12].

The most commonly used orthoses for de Quervain's tendonitis are the long opponens splint and thumb spica splint [13,14] (Fig. 1). The long opponens splint is an orthosis that controls the wrist joint by connecting the forearm bar to the basic opponens orthosis [15]. Proximal and distal cross bars located on the long, dorsal, radial, or ulnar side of the forearm are connected to the forearm bar [15]. The main function of the long opponens splint is to maintain the wrist joint in a fixed position and prevent wrist drop [15]. If a hinge is added to the long opponens splint, wrist flexion and extension are possible; however, ulnar and radial deviations are limited. The addition of a hinge results in better patient compliance and higher satisfaction than with the fully fixed type. The thumb spica splint is designed to immobilize the thumb and wrist and allow the other four fingers to move freely. In general, the palm and back of the hand are unrestricted to minimize movement restrictions, thereby reducing discomfort while performing daily life activities [13]. The distal thumb and wrist are secured with Velcro straps.

Figure 1. Orthoses for de Quervain's tenosynovitis; (A) long opponens splint, (B) thumb spica splint.

In 2020, Liu et al. [16] compared the effects of long-and short-thumb orthoses use in 12 patients with chronic de Quervain’s tenosynovitis and 16 healthy participants. To assess the effectiveness of the orthoses, the optimal handle diameter was investigated; moreover, as individuals with chronic de Quervain's tenosynovitis require greater muscle loads than healthy controls to produce the same grasp power, differences in forearm muscle activity when wearing the orthoses were also evaluated. The study found no significant differences in muscle activity between the two orthoses groups. Thus, since wearing both orthoses requires the almost same exertion of muscle load, both long-and short-thumb orthoses can be worn by individuals with de Quervain's tenosynovitis during daily activities. This study suggested that patients with de Quervain’s tenosynovitis should use utensils with larger handle diameters, such as 45 mm and 55 mm.

Carpal tunnel syndrome is caused by pressure on the median nerve due to the narrowing of the carpal tunnel, which occurs because of excessive use of the wrist, rheumatoid arthritis, edema caused by tuberculosis, or tumors within the carpal tunnel [7,17]. It is more common in women, the elderly, and patients with diabetes [7,17]. Early-stage symptoms of carpal tunnel syndrome include numbness and a burning sensation in the fingers, impaired motor function due to numbness in the hands, and sensory abnormalities [7]. When symptoms worsen, sensation on the thumb side decreases, causing weakness and atrophy of the thumb muscles [7]. Treatment methods include medication, orthosis, physical therapy, exercise therapy, extracorporeal shock wave therapy, injection therapy, and surgery [7].

The orthoses used to manage pain in carpal tunnel syndrome include wrist-hand orthoses such as the resting pan splint, cockup splint, and thumb spica splint (Fig. 2) [13,15,18]. Wrist-hand orthoses fix the hand and wrist in a functional position such that the median nerve is not compressed [19]. The resting pan orthosis is a wrist-hand orthosis that is worn on the palm of the hand to maintain a functional posture of the hand and wrist [15,20,21]. The wrist is fixed to maintain the dorsiflexion posture of 20 to 30 degrees, and the metacarpophalangeal joint (MCP) is immobilized to maintain 40-45 degrees of flexion [15,22]. However, this orthosis encloses the entire palm of the hand, thereby limiting its activity. On the other hand, the cock-up splint is open, so that the fingers can move freely. It is fabricated so as to cover only parts of the forearm, wrist, palm, and back of the hand. The design can vary depending on the patient's preference or condition; however, the wrist is maintained in dorsiflexion (20-30 degrees) and the transverse palmar arch of the palm is supported [15]. The thumb spica splint has been designed to fix the thumb and wrist while allowing the remaining four fingers to move freely [13]. It helps prevent compression of the carpal tunnel by immobilizing the wrist in a neutral position when trying conservative treatment [23]. The thumb spica splint is also used for about 4 weeks to maintain full thumb palmar abduction and neutral wrist position after carpal tunnel syndrome surgery [24,25]. It has a metal splint for fixation and is entirely covered with soft, breathable fabric. It is easy to use because it can be easily attached and detached using a Velcro strap.

Figure 2. Orthoses for carpal tunnel syndrome; (A) resting pan splint, (B) cock-up splint.

In 2021, Farahmand et al. [26] investigated the effects of the volar wrist cock-up splint and dorsal lock wrist-hand orthoses in reducing the symptoms of carpal tunnel syndrome. Thirty patients diagnosed with mild to moderate carpal tunnel syndrome were randomly divided into two groups and fitted with one type of splint for 3 weeks. For the dorsal lock splint, the wrist was placed in a neutral position (0-5 degrees), and the MCP joint was positioned at 0-10 degrees of flexion. The proximal interphalangeal (PIP) joint had 20-30-degrees of flexion, whereas the distal interphalangeal joint (DIP) and the MCP joint of the thumb were free to move in all directions. In a volar wrist cock-up, a splint wraps around the wrist in a neutral position (0-5 degrees) and ends just proximal to the MCP. Subjects continued to wear splints at night and only wore splints during the day when they wanted to. Pain was after 3 weeks of using the splint based on with the 11-point Numerical Rating Scale (NRS-11). In the volar wrist cock-up splint group, the average NRS-11 score decreased significantly from 4.85 points before the use of the splint to 4.17 points after its use (P = 0.015). In the dorsal lock wrist-hand orthosis group, the mean NRS-11 score decreased significantly from 4.75 points before orthosis use to 4.27 points after orthosis use (P = 0.020). These results suggest that wrist-hand orthoses are effective in reducing pain caused by carpal tunnel syndrome.

Osteoarthritis can be classified as degenerative arthritis, caused by wear and tear of the cartilage, or rheumatoid arthritis, a type of autoimmune disease [27]. Degeneration is not unconditionally related to age; especially in recent times it has been found to be closely related to the frequency of use of various digital devices such as computers and smartphones, and therefore often occurs in younger populations as well [2,3]. Thus, degenerative arthritis can be caused by aging of the joints, gradual damage to cartilage, or excessive use of finger joints [28]. Rheumatoid arthritis is a disease in which the immune system begins to function abnormally, resulting in swelling, pain, and joint deformation [29]. Osteoarthritis usually affects the carpometacarpal joint of the thumb (21% of cases) and the PIP and DIP joints (35% of cases) [30]. When osteoarthritis occurs, knuckles become stiff and difficult to move upon waking up in the morning, their movement becomes limited, and the pain worsens in the late evening [31,32]. The joint pain may become continuous and patients may hear noises when the moving the joints. In rheumatoid arthritis, the hands swell every morning, and patients may experience pain and erythema on the palms [32]. Symptoms can be relieved by medication, joint stabilization using an orthosis, and stretching. If the condition is severe, surgical interventions may be required [31].

Studies have reported that orthoses can reduce pain and improve function in patients with osteoarthritis during daily activities [33]. A finger knuckle bender is used to treat swan-neck deformities caused by rheumatoid arthritis (Fig. 3) [15]. It has two bands on the dorsal side of the fingers and a rod on the long side of the PIP joint. This orthosis flexes the PIP joint and extends the DIP joint according to the three-point pressure principle [15]. The silver splint orthosis consists of a combination of oval rings made of pure silver (Fig. 4) [34]. It is easier to wear and has an improved appearance compared to the finger knuckle bender. It serves to properly support the joint and is known to relieve pain by limiting the movement of the joint within its full range of motion [34]. Moreover, silver is a hypoallergenic material with antibacterial properties and is durable, easy to clean, and resistant to wear and tear [34]. There are no rough surfaces, and therefore it does not irritate the skin, does not create any pressure points, and allows relatively free movement of the hand and fingers [31]. However, since silver does not prevent sweating or clogging of skin pores, it can cause odor or skin rashes; therefore, caution should be exercised when using it [34].

Figure 3. Finger knuckle bender.

Figure 4. Silver splint.

In 2021, Roux et al. [34] reported patient-reported outcome measures for 850 patients with hand osteoarthritis who used a silver splint for at least 3 weeks. The patients received and responded to a questionnaire about the effect of the splint 3 weeks after first wearing it—76% of respondents reported that their overall daily functioning improved after using the silver splint (some improvement: 29%, significant improvement: 42%, very significant improvement: 5%). Patients were also asked how much hand and finger function and different types of grips improved and reported significant improvements in all activities that required fine motor skills, such as grasping hands more openly, picking up groceries, and opening bottle caps. Seventy-four percent of respondents reported a reduction in pain after using the silver splint (some improvement: 31%, significant improvement: 38%, very significant improvement: 5%). The results of this study indicate that the silver splint is effective in supporting the joints of the hand in osteoarthritis. In addition, it can be considered a useful tool for treating patients with hand osteoarthritis.

Medial and lateral epicondylitis affects the tendons attached to the inner and outer parts of the elbow [35,36]. In lateral epicondylitis, when the fingers are extended or the wrist is lifted, these tendons need to be used, which results in pain [35]. Medial epicondylitis is pain on the inside of the elbow when attempting activities such as gripping or throwing, and pronation or flexion of the forearm [36]. Medial and lateral epicondylitis are generally caused by overuse of the wrist and elbow joint or repeated trauma to the elbow [35,37]. Elbow pain worsens when holding or lifting heavy objects; at more advanced stages, pain occurs with all elbow movements, and sleep disturbances due to night-time pain can occur [38]. Medication, physical therapy, exercise therapy, use of orthoses, regenerative injection, ligament strengthening injection, and extracorporeal shock wave therapy are used for treatment [35,37]. Surgical treatment is considered when conservative treatment is ineffective [36].

Orthoses help relieve pain by supporting the overused tendons, reducing tension in the elbow area, and suppressing inflammation [15,39,40]. A forearm band (forearm cuff) is usually used to manage epicondylitis pain (Fig. 5) [39]. It is positioned approximately 2.5 cm below the elbow [36,39]. The width of the band is 5-8 cm, and it is fixed with a Velcro strap [39,41]. If the width is too narrow, it may not be sufficient to compress the inflamed tendon effectively. The inside of the band is padded with a cushion, gel, air, or plastic to reduce friction on the skin in the compressed area. A point to be aware of when using the forearm band is that circulation disorders may occur, and therefore it is recommended that the band is loosened to relieve the tension every 3 to 4 h and to not wear it at night [15]. Another orthosis is the elbow sleeve, which consists of two straps approximately 5 cm in width that wrap approximately 15 cm above and below the elbow to fix and tighten the sleeve (Fig. 6) [39,41]. Similar to the forearm band, it is a counterforce orthosis; however, the elbow sleeve characteristically covers the elbow.

Figure 5. Forearm band.

Figure 6. Elbow sleeve.

In 2019, Barati et al. [41] evaluated the effectiveness of the forearm band and elbow sleeve in patients with lateral epicondylitis. This was a randomized controlled crossover study, and the immediate effect of orthosis was evaluated. Pain was evaluated using the visual analog scale (VAS), hand grip strength was evaluated using a digital handgrip dynamometer, and finger dexterity was evaluated using the 9-hole peg test. Grip strength is expressed in newton, the unit of force, and finger dexterity is expressed in seconds spent performing the 9-hole peg test. The average VAS scores in the no orthosis, forearm band, and elbow sleeve groups were 5.8, 4.1, and 4.5, respectively. Among the three interventions, pain relief was highest in the forearm band group, although there was no significant difference between the two orthoses (P > .05); however, there was a significant difference between the two orthoses and the no orthosis condition (P < .001). The average hand grip strengths in the no orthosis, forearm band, and elbow sleeve groups were 157.63 N, 189.14 N, and 186.9 N, respectively. The effect was the best when wearing the forearm band, and there was no significant difference between the two orthoses (P > .05), while both orthoses had a significant effect compared with the no orthosis condition (P < .05). The finger dexterity test results in the no orthosis, forearm band, and elbow sleeve groups were 16.57 s, 15.5 s, and 16.02 s, respectively. The most effective results were obtained when the forearm band was worn, and there were no significant differences between the no orthosis and elbow sleeve groups and between the two orthoses groups (P > .05); however, the forearm band had a significant effect compared to the no orthosis condition (P < .001). Thus, both the forearm band and elbow sleeve could relieve pain and improve hand grip strength in lateral epicondylitis, and the forearm band was also effective in improving finger dexterity. Use of the forearm band can therefore be considered a successful intervention method for lateral epicondylitis.

Shoulder dislocation occurs due to rupture of the labrum at the interface of the scapula and the joint and can be categorized in terms of anterior, posterior, or inferior instability [42]. In many cases, it is caused by trauma, exercise, or sports activities [42,43]. When shoulder dislocation occurs, the arm droops downward when used to lifting heavy objects or exert an excessive force. In addition, when assuming a throwing posture, the arm may fall out or feel awkward, and if the nerve is damaged, paralysis may set in. If the initial symptoms or instability are not severe, they can be treated with physical therapy, exercise therapy, or an orthosis [43]. Surgical treatment is considered if the disability is severe or if there is no response to conservative treatment [43].

In the event of a shoulder dislocation, it is advisable to use a sling-type orthosis that fixes the shoulder joint in an externally or internally rotated state in order to restore the labrum to an anatomically correct position [44,45]. Orthoses for shoulder dislocation usually have a strap that wraps around the trunk and is made of a ventilatable material. To prevent adduction contracture, a cushion can be placed between the upper arm and the trunk as needed [46]. Shoulder dislocation orthoses are of several types, with the shoulder either left uncovered or completely enclosed (Fig. 7). The orthosis is designed to prevent secondary damage to the capsule, tendon, muscle, and nerves through the traction effect; relieve pain; and induce relocation of the humeral head [15,47]. Excessive rotation of the joint while wearing the orthosis can cause discomfort in daily life; therefore, maintaining the rotational posture within the possible joint range is recommended [15]. In addition, this method may not be helpful for patients with recurrent dislocations, and is mostly used for patients with first-time dislocations [43].

Figure 7. Orthoses for shoulder dislocation; (A) Bobath sling, (B) orthosis for correcting shoulder dislocation that completely covers the shoulder.

In 2012, Hartwig et al. [48] evaluated the effectiveness of the Neuro-Lux (Sporlastic, Nürtingen, Germany), an orthosis for correcting shoulder dislocation, in 41 patients with post-stroke shoulder joint subluxation. The Neuro-Lux completely covers the shoulder, and the suspension strap wraps around the trunk to fix it in place. The Neuro-Lux is a similar type to Fig. 7B. Patients were randomly divided into two groups—20 were assigned to the experimental group and used the orthosis, whereas the 21 patients in the control group received usual care. The severity of clinical symptoms was evaluated based on shoulder-hand syndrome scores (0 to 14 points). At the end of the 4-week intervention period, the average shoulder-hand syndrome score in the experimental group was 1.8 points and that in the control group was 5.3 points (P < .0001). These results suggest that this orthosis is successful in reducing and preventing the onset of the clinical symptoms of shoulder-hand syndrome in patients with shoulder joint subluxation after stroke.

Patients with upper extremity pain are often encountered in clinical practice, and upper extremity orthoses have been reported to be helpful in improving the associated symptoms, especially pain. However, our study reviewed only the most commonly occurring conditions that cause upper extremity pain and a limited number of orthoses. Therefore, future studies should review other diseases and orthoses as well.

This research received no external funding.

No potential conflict of interest relevant to this article was reported.