Protective Sport Bracing for Athletes With Mid-Season Shoulder Instability

Abstract

Context:

In-season glenohumeral instability is a common clinical dilemma faced by physicians who care for athletes. Both nonoperative and operative management of athletes with in-season glenohumeral instability have been well described. Functional bracing remains less understood as a treatment modality. This review aims to provide an update on the most recent literature regarding the use of functional bracing for shoulder instability.

Evidence Acquisition:

MEDLINE (PubMed and Ovid platforms), Web of Science, Embase, and Cochrane Database of Systemic Reviews were searched for articles available in English through June 1, 2021. The search terms shoulder brace, shoulder instability, athlete, in-season, glenohumeral instability, anterior shoulder instability, posterior shoulder instability, and bracing were used.

Study Design:

Clinical review.

Level of Evidence:

Level 3.

Results:

Research on the clinical outcomes of functional bracing remains mixed for patients with shoulder instability. Two studies have demonstrated improved return to play with functional bracing, while 1 study demonstrated no difference in return to play between braced athletes and nonbraced athletes with anterior instability. One previous study demonstrated that prophylactic use of bilateral shoulder stabilizing braces significantly decreased time lost due to injury in athletes with posterior instability. Previous biomechanical studies have demonstrated improved proprioception with brace wear as well as successful limitation of active shoulder range of motion.

Conclusion:

Bracing in athletes with shoulder instability remains an important nonoperative treatment modality. While clinical benefits are yet to be validated through high-quality studies, preliminary results suggest a potential benefit to recovery, with minimal downsides. Nevertheless, the use of bracing remains an individual choice but is especially recommended in settings of high-risk sports for shoulder instability, such as football.

In-season glenohumeral instability is a common clinical dilemma faced by physicians who care for athletes. The reported incidence of glenohumeral instability in collegiate athletics is 0.12 injuries per 1000 athlete-exposures, according to a retrospective review of the U.S. National Collegiate Athletic Association database from 1989 to 2004. ²⁸ Not surprisingly, the incidence rate of shoulder instability increases among participants in contact sports with men’s Spring Football reporting the highest rate of instability—0.40 injuries per 1000 athlete-exposures. ²⁸ Most glenohumeral instability events occur secondary to contact injuries, often from contact with another player. ³⁰

While glenohumeral instability encompasses a spectrum of injuries, the most common episode accounting for 85% of new traumatic anterior shoulder instability events is glenohumeral subluxation.^25,30,31 Glenohumeral subluxation is defined as translation of the humeral head beyond physiologic limits, with maintained glenohumeral contact. Less commonly, glenohumeral dislocation can occur where there is complete disassociation of the glenohumeral surfaces, often requiring closed reduction. ²⁵ These instability events pose a difficult challenge to both the in-season athlete and the treating physician. While the ultimate goal is to assist the athlete in promptly returning to sport, the physician must also aim to minimize the risk of reinjury. Recurrent instability has been shown to result in cumulative glenohumeral attritional bone loss and articular cartilage damage leading to the development of osteoarthritis and chronic instability. ²⁵

Both nonoperative and operative management of athletes with in-season glenohumeral instability have been well described.^{2,9,10,15,16,18,25,30,39,40,42} Most in-season nonoperative treatments focus on immobilization and rehabilitation^7,20; however, functional bracing remains less understood as a treatment modality. While many shoulder braces are currently available on the market, ³⁵ few studies have looked at their clinical impact in preventing recurrent instability and allowing for a successful return to sport. This review aims to provide an update on the most recent literature regarding the use of functional bracing for shoulder instability, and to serve as a guide for clinicians when conducting in-season nonoperative management.

Pathoanatomy

Anterior shoulder instability remains overwhelmingly more common than posterior shoulder instability, accounting for 90% of all shoulder instability events in a young, active population.^1,8 Traumatic anterior shoulder subluxation or dislocation often results from a contact injury while the arm is held in an abducted and externally rotated position. Glenohumeral instability events often result in damage to both the soft tissue (glenoid labrum) and osseous structures (glenoid, humeral head) of the shoulder. When involving the anterior inferior glenoid labrum, these “Bankart lesions” are especially prevalent in athletes^32,37 and are associated with recurrent instability.^34,37,41

Posterior shoulder instability differs from anterior shoulder instability not only in its prevalence but also in its etiology. Currently, 3 mechanisms have been proposed. The first being repetitive microtrauma progressing to chronic attenuation injuries of the posterior labrum and capsule. The second involving an acute traumatic posterior force resulting in capsulolabral detachment, and finally insidious onset of laxity resulting in attenuation of the posterior capsule and labrum. ¹ These injuries typically occur in athletes participating in posterior loading activities in the provocative position of flexion, adduction, and internal rotation, seen in weightlifters, football linemen, and patients with seizure disorders.^1,8 Analogous to that seen in anterior instability events, injuries to the posterior labrum and osseous structures can lead to posterior labral detachment, termed “reverse Bankart lesions” or “reverse bony Bankart lesions,” depending on the additional presence of associated glenoid rim fractures. These lesions are also found to lead to an increased rate of recurrent instability. ²⁹

Biomechanics

As the repetitive positioning of the glenohumeral joint in the extreme range of motion (ROM) can lead to an increased risk of shoulder instability, ²⁴ athletes can use functional shoulder braces to limit extreme shoulder abduction, extension, and external rotation. Three previous studies have investigated the effectiveness of shoulder braces in limiting active joint motion. In a prospective laboratory study comparing active shoulder ROM between 3 braces (Duke Wyre harness, CD Denison Orthopaedic Appliance Corp; SAWA shoulder brace, Brace International; and Shoulder Subluxation Inhibitor, Boston Brace International, Inc), DeCarlo et al ¹³ reported that all included braces decreased active shoulder ROM; however, they noted loosening and increased motion with active flexion for all 3 braces after exercise. Similarly, Mcleod et al ²⁶ investigated 4 shoulder braces (SAWA shoulder brace, Sully brace, SaundersGroup; Douglas shoulder sling, Douglas Protective Equipment), and a homemade elastic restraint (shoulder strap) and found that all 4 braces, again, initially limited active shoulder ROM but loosened after exercise, resulting in a significant increase in active shoulder abduction and external rotation. Dellabiancia et al, ¹⁴ in a prospective laboratory study investigating shoulder joint excursion while wearing the S2 Shoulder Stabilizer (Dual Sanitaly SpA), demonstrated significantly limited joint excursion in all planes of movement, except internal rotation, as well as narrower humeral head translation. The authors concluded that the S2 Shoulder Stabilizer improves joint stability during movements that are at risk for dislocation. ¹⁴

The positive effect of lower extremity bracing on joint position sense and injury prevention has been well described^{4 -6,17,19,21,22,27,33,36}; however, only 2 previous studies have investigated the effect of shoulder bracing on joint proprioception. In a biomechanical study measuring shoulder joint position sense, Chu et al ¹¹ demonstrated that shoulder bracing significantly improved joint position sense in individuals with a history of shoulder instability, but they reported no significant difference in joint position sense in individuals with no history of shoulder instability. Ulkar et al, ³⁸ in a similar biomechanical study investigating the effect of bracing on shoulder proprioception, went on to demonstrate improved joint position sense with bracing in individuals with no history of shoulder instability. Both studies used the Sully Shoulder Stabilizer neoprene sleeve for their investigations. The authors speculate that the improvement in active joint position sense is because of the brace stimulating superficial receptors in the skin and muscle, including free nerve endings, hair end organs, and Merkel discs.^11,38 They suggest that by enhancing proprioception, shoulder braces may prevent shoulder instability through facilitation of improved neuromuscular input and control at the extreme ranges of shoulder external rotation.^11,38

One previous study investigated the effectiveness of shoulder braces in limiting active and passive shoulder ROM. Weise et al ⁴¹ compared the Denison and Duke Wyre harness and SAWA shoulder brace’s abilities to limit passive and active abduction and external rotation. Each brace was set to limit abduction to 45° during participant testing. They found that active abduction and external rotation, as well as passive abduction and external rotation, increased in both groups beyond the preset 45° limitation. Passive abduction and external rotation increased to a greater extent than active. The SAWA shoulder brace limited motion more effectively than the Denison and Duke Wyre harness for all the testing conditions. The authors concluded that preset, braced abduction motion limits were not achieved during active and passive physiologic loading of the shoulder; however, the braces did offer protection against the vulnerable position of 90° of abduction and external rotation at a preset braced limit of 45° of abduction.

Type Of Braces

The ideal brace stabilizes the shoulder without impeding function. When considering if an athlete should use a sports brace to prevent instability, an individualized approach is encouraged, taking into account the requirements of their sport and specific position.^{9,15,25,30,35,41,42} Many studies^{9,15,25,30,35,41,42} stratify athletes roughly into 2 cohorts, with one including overhead athletes where full ROM is required and another with contact athletes where full ROM is not required. Overhead athletes require extremes of motion, which motion-limiting braces do not permit. However, contact athletes, such as football linemen, require much less shoulder ROM to play their position and may be less affected by the restrictions of a motion limiting brace.

Alternatively, Reuss et al ³⁵ stratified brace type into 3 categories based on mechanism of preventing recurrent instability. Type A braces are defined as motion-limiting braces that prevent extreme shoulder abduction, extension, and external rotation. Type B braces prevent instability through an indirect stabilizing force, and type C braces utilize a direct stabilizing force. The authors acknowledge that all 3 types of braces can potentially impede athletic function and emphasize consideration of an athlete’s position requirements to help guide the decision of which type of brace to use. They then go on to subjectively review 13 braces and comment on various concerns including comfort, convenience of application, cost, and cosmesis. Ultimately, the authors do not make specific recommendations for brace use but do offer guidelines for brace selection. Further details on brace type and potential use for sport are included in Table 1.

Table 1.

Brace type and potential use for sport

Name (Supplier/Cost)	Brace Type	Construction	Potential Sport Use a
Donjoy Shoulder Stabilizer SPA (DJO/$156.99)	A	Elastic arm band with adjustable shoulder straps that attach directly to shoulder pads	4
Douglas shoulder sling (Douglas Protective Equipment/$99.00)	A	Adjustable arm restraint that attaches directly to shoulder pads	4
Duke Wyre harness (CD Denison Orthopaedic Appliance Corp/$115.95)	A	Leather with adjustable shoestrings that help limit abduction and extension but not external rotation	4
S2 Shoulder Stabilizer (Dual Sanitaly SpA/$161.00)	A, B	Neoprene sleeve with elastic strap that limits active abduction and external rotation	2, 3, 4
Donjoy Shoulder Stabilizer/SAWA (DJO/$156.99)	A, C	Polyester Lycra shoulder sleeve with adjustable Velcro straps	2, 3, 4
Sully Shoulder Stabilizer (DJO/$156.94)	A, B	Neoprene shoulder sleeve with adjustable hook and hard-shelled foam pad to protect acromioclavicular joint	1, 2, 3, 4

^a1 indicates skilled overhead use (throwers), 2 indicates skilled overhead use (nonthrowers), 3 indicates contact athlete full range of motion (ROM) required (basketball), and 4 indicates contact athlete full ROM not required (football linemen).

The most commonly recommended brace for an overhead athlete that requires full ROM is the Sully brace (Figure 1).^9,25,30,42 The Sully brace is a neoprene sleeve with elastic straps that wrap around an athlete’s affected shoulder and torso. The elastic straps and neoprene material provide relative restriction to abduction and external rotation. However, given the elastic nature of the brace, it does not restrict as much as a motion-limiting brace. ¹² But the Sully brace does permit adequate ROM that is needed for an overhead type of athlete to perform. ¹² For contact athletes who do not require full shoulder ROM, the SAWA brace is commonly recommended (Figure 2).^9,25,30,42 Similar to the Sully brace, the SAWA brace is also a neoprene sleeve that wraps around the torso and affected shoulder. However, the SAWA brace also utilizes nylon straps that originate from the torso portion of the brace and wrap around the arm, which further limit abduction and external rotation. The SAWA brace trades increased stability for ROM. Contact athletes who do not require extremes of shoulder ROM for their sport, such as football linemen, may be better suited for a SAWA.

Figure 1.

SAWA shoulder brace.

Figure 2.

Sully shoulder brace.

Clinical Outcomes Of Bracing

There is limited research evaluating clinical outcomes of sports bracing in athletes to prevent first-time or recurrent shoulder instability. To date, 4 studies have been published that specifically investigate clinical outcomes of shoulder bracing in athletes with shoulder instability: 3 studies investigated athletes with anterior instability and 1 study investigated athletes with posterior instability.

Anterior Instability

Research on the clinical outcomes of functional bracing remains mixed for patients with anterior shoulder instability. In a recent study, Kwapisz et al ²³ looked at the return-to-play outcomes for 97 adolescent athletes treated nonoperatively and found that the Sully brace did not significantly change rates of successful return to season play, with braced athletes (n = 20) returning 80% of the time and nonbraced athletes (n = 77) returning 88% of the time. Additionally, given that football athletes comprised 85% of the study population of braced athletes, a football-specific analysis was conducted, which also failed to show any significant difference in return to play between braced (n = 20) and nonbraced (n = 25) athletes (74% vs 84%, respectively). ²³ However, Conti et al ¹² followed 20 soccer players and found that rehabilitation with a dynamic eKeep S2 motion limiting brace allowed 18 athletes (90%) to return to play after 40 days with no symptoms of pain, discomfort, or instability. Additionally, in another study ¹⁰ of 30 athletes across various sports, 8 were able to successfully return to play without the use of a brace while 19 reported subjective improvement and the ability to play at previous competition levels with the use of a Duke Wyre brace for nonoverhead sports (n = 15) or Sully brace for overhead sports (n = 4).

Posterior Instability

As mentioned earlier, only 1 previous study has investigated clinical outcomes of prophylactic shoulder bracing in athletes to prevent posterior shoulder instability. In a study of 45 collegiate offensive linemen over multiple seasons, Baker et al ³ found that the prophylactic use of bilateral shoulder stabilizing braces significantly decreased time lost due to injury with braced athletes missing an average of 8.7 contact practices and games compared with 36.6 for nonbraced athletes. The authors of the study investigated the Donjoy Shoulder Stabilizer brace. The Donjoy Shoulder Stabilizer brace uses straps attached to the front breastplate of a football player’s shoulder pads that attach to a Velcro cuff worn on the player’s arm. This positioning serves as an anchor and helps prevent posterior glenohumeral instability by limiting abduction, external rotation, internal rotation, and forced posterior subluxation. While the authors also found that braced athletes experienced a decreased injury rate of posterior labral tears compared with nonbraced athletes, these results were not statistically significant because of small sample size, meriting further study. ³

Management

While successful return to sport may be the ultimate goal of many athletes with in-season shoulder instability, this review solely focuses on the use of shoulder bracing to aid recovery in patients with shoulder instability being treated nonoperatively. As described previously, the variety and adaptability of braces remains a positive feature of their use, allowing for each athlete to make an individual and informed choice depending on their specific injury, respective sport, and ultimate preference and goals. Indeed, there is no consensus in the relevant literature on clinical outcomes to guide this choice because of the variety of braces and sports studied. While football athletes were found to have no recovery benefit from bracing in 1 study, ²³ soccer athletes were complicating efforts to isolate the effects of shoulder bracing. ¹² Furthermore, as suggested by some authors,^3,23 any potential statistically significant findings may have been obscured because of small sample sizes in the study population. Other possible drawbacks of bracing include financial costs, personal comfort, and even a false sense of security. But more likely, they may cause positive psychological effects, allowing for an improved sense of stability and the ability to play at previous competition levels after injury, as subjectively reported by athletes in 1 study ¹⁰ and demonstrated in biomechanical studies on proprioception.^11,38

However, in contact sports known to have a high risk of shoulder instability, such as football,^28,30 prophylactic bracing may be warranted to decrease time lost due to injury and even potentially decrease risk of injury. ³ The psychological benefit of bracing should also be considered, allowing for an improved sense of stability and the ability to play at previous competition levels after injury, as subjectively reported by athletes in 1 study ¹⁰ and demonstrated in biomechanical studies on proprioception.^11,38 Taken together, bracing seems to offer the potential of both physical and psychological benefits, with few reported drawbacks.

Summary

The use of bracing in athletes with shoulder instability remains an important nonoperative treatment modality. While clinical benefits have yet to be validated through high-quality studies, preliminary results suggest a potential benefit to recovery, with minimal downsides. Going forward, studies involving the use of a larger sample size to derive statistically significant results would be beneficial in further elucidating the clinical benefit of bracing. Nevertheless, the use of bracing remains an individual choice but is especially recommended in settings of high-risk sports for shoulder instability, such as football.