Therapeutic Implementation of a Custom Dynamic Elbow Brace... : Pediatric Physical Therapy (2024)

INTRODUCTION

Brachial plexus injury is a disruption to the group of nerves from the cervical spinal cord (C5-C8) and first thoracic nerve root (T1) that stimulate and control muscle activation and sensation of the chest, shoulder, elbow, and hand.¹ Brachial plexus injuries are typically unilateral and may involve trauma, obstetric complication, or iatrogenic lesions. The mechanism of injury may involve stretching, traction, torsion, severing, inflammation, neuroma, tumor, or compression of the nerve tissue or from a direct trauma or laceration.

Birth-related brachial plexus injuries are referred to in the literature as neonatal brachial plexus palsy (NBPP), obstetric brachial plexus injury (OBPI), perinatal brachial plexus injury (PBPI), brachial plexus birth palsy (BPBP), or birth brachial plexus injury (BBPI). The etiology includes compression, torsion, or traction of the brachial plexus in utero, during descent through the birth canal or during delivery.²^,³ Risk factors range from labor induction, failure to progress, prolonged labor, primiparity, maternal gestational diabetes, fetal macrosomia, fetal hypotonia, breech/atypical birth presentation, twin or multiple births, shoulder dystocia, and difficult deliveries requiring mechanical assisted extraction.¹^,²^,⁴ The average incidence occurs in 1 to 3 per 1000 live births in the United States and has reportedly been decreasing with advancements in obstetric practice for fetal and maternal health and an increase in cesarean delivery.³^,⁵ Spontaneous recovery is between 65% and 95%, typically within the first several months of life.¹^,⁶ When neurologic dysfunction persists at 3 to 6 months of age, more specific rehabilitation and surgical options are considered.³^,⁵^,⁷^,⁸

The spinal cord nerve roots typically affected are C5-C8 and T1 and the major nerve branches extending from the brachial plexus: the upper and lower subscapular, thoracodorsal, axillary, radial, medial and lateral pectoral, musculocutaneous, median and ulnar, sensory and motor nerves, each correlating to specific muscles for mobility of the shoulder, elbow, hand, and fingers. Additionally, the phrenic, subclavian, long thoracic, and/or scapular nerves are affected as identified by elevation of the ipsilateral hemidiaphragm, scapular winging, and/or weak rhomboids.²^,⁶

The extent and severity of the impairments, prognosis for recovery, plan for intervention, and likely outcome vary according to the type of injury, evaluative findings and spontaneous recovery within the first few months post-injury. The type of injury to the brachial plexus is commonly classified into 4 groups by Narakas,⁹ modified by Al-Qattan et al,¹⁰ as upper Erb's palsy (C5, C6), extended or middle Erb's palsy (C5, C6, C7), global or complete palsy with no Horner's syndrome (C5-C8, T1), and global or complete palsy with Horner's syndrome (C5-C8, T1). Extended or middle Erb's palsy (C5, C6, C7) was further subclassified by Al-Qattan et al¹⁰ according to early recovery of antigravity wrist extension before 2 months of age.⁴ Another type is the lower or Klumpke's paralysis (C8 and T1), affecting the intrinsic muscles of the hand.²

The classification of nerve lesions by Seddon,¹¹ and more finely detailed by Sunderland,¹² describes the degree of injury to the nerve and is a useful diagnostic system for prognosis and intervention strategies. The degree of injury indicates the number and length of the nerve roots affected. The most severe type and third-degree injury is a peripheral or central avulsion, rupture, or neurotmesis, which Sunderland further delineated noting involvement of the endoneurial tubes, perineurium, and epineurium, respectively. A moderate or second-degree injury is characterized by damage of the axons and myelin sheath called axonotmesis. And, a mild or first-degree injury would consist of an overstretch, distraction, or pull of the nerve(s) of the brachial plexus known as a neurapraxia.

Diagnosis of NBPP is confirmed by an ultrasound, electromyography, computed tomography, myelography, or magnetic resonance imaging (MRI).⁶ Clinical assessments for infants and children with NBPP include neurologic, range of motion, strength, posture, and functional movements and abilities. The neurologic component includes assessment of muscle tone (Modified Ashworth Scale,¹³) primitive reflexes, deep tendon reflexes, sympathetic nervous system, and sensation (Narakas sensory grading system).⁴ The motor assessment may include goniometric passive and active range of motion, manual muscle strength testing (manual muscle test—MMT¹⁴^,¹⁵ or modified Medical Research Council Scale—MRC grading¹⁴^,¹⁵) and administering tools designed specifically for infants and children with NBPP. The Toronto Test Score quantifies 5 active upper extremity movements, from infancy, on a 7-point grading system.¹⁶ The Active Movement Scale measures muscle activation in 15 functional joint movements using an 8-grade, ordinal scale and is standardized for children from birth through age 15.⁴^,^15–17 The Mallet or Modified Mallet Scale evaluates the ability to perform 6 functional positions and is used with cooperative children, reliably after age 3.⁴^,⁷^,¹⁵^,¹⁶ And, the Brachial Plexus Outcome Measure is a tool that measures activity and participation, with a self-evaluation, designed for school-aged children beginning at age 4.⁴^,¹⁸

While NBPP is not a progressive disorder, it is variable during the recovery phase and growth of a child. Secondary abnormalities such as atrophy, impaired reflexes, contracture, somatosensory deficits, or postural asymmetries also influence potential outcomes. The Narakas Classification⁹^,¹⁰ is the gold standard prognosticator. Bicep function is another predictor of spontaneous recovery. Spontaneous recovery, when nerve tissue is preserved, is notable within the first 3 months of life. Failure of antigravity bicep recovery or contracture of the bicep, after more than 3 months, indicates pathology of the affected nerves and muscles. The structure and function of these tissues are impaired and impact rehabilitation. Typically, elbow flexors, shoulder flexors, abductors, and external rotators that are innervated by the posterior cord are the weakest group of muscles.²^,⁸^,¹⁹^,²⁰ During reinnervation, a child might demonstrate atrophy, incomplete motor recovery, or simultaneous contractions before potentially gaining the strength required to isolate a muscle or group of muscles. Muscle imbalances prevail when there is recovery of strength in a muscle or muscle group in the presence of an atrophied or weak muscle or muscle group.²^,⁶^,⁸^,²⁰ Overtime, when muscles are unopposed, atypical cocontractions develop, compensatory movements occur, progress plateaus and impairments persist.⁶ Asymmetries related to muscle function during the recovery phase affect posture, bone/joint integrity, alignment and movement, growth of the long bones, and the stability and mobility of muscles. Whether this cocontraction is initiated from cross reinnervation or from learned functional movement patterns, it is part of the rehabilitative process. Children who demonstrate limited stability and mobility often adapt their movement pattern for independent function. Muscle imbalances, improper mechanics, and postural asymmetries impede progress when compensatory habits develop.

The priorities of rehabilitation for children with NBPP are range of motion, strength, and function. Dynamic bracing enables controlled active mobility used to facilitate movement and strengthening against gravity earlier in the recovery process.²¹

The focus of this case analysis is to highlight the benefits and functional outcomes when using a custom dynamic elbow brace as an adjunct to therapeutic interventions for children diagnosed with NBPP. Using a dynamic elbow brace with capabilities to immobilize, add a dynamic functional assist or add resistance promoted the stability-mobility relationship for effective movement and function. The features also contributed to the ability to strengthen muscles through a larger range of motion, provided increased potential for functional mobility and range of motion gains, muscle reeducation, proprioceptive feedback, and perhaps even cortical reorganization.

THE CASE

This child, now a girl who is 30 months old, was born at 38 weeks' gestation with a birth weight of 10 lb 6 oz. Early labor was induced secondary to maternal high blood pressure. The delivery was further complicated with an occipitoposterior fetal position and difficulty bringing her shoulders through the birth canal. Vacuum extraction was used to assist in her delivery. The infant was diagnosed with a flail right arm after birth. An MRI was performed at 2 months of age, which revealed a pseudomeningocele at the right C7-T1 neuroforamen consistent with a right C8 nerve avulsion as well as a smaller pseudomeningocele at C6-C7, also compatible with avulsion of the right C7 nerve root. At 9 months of age, she had a surgical procedure including exploration with neurolysis and nerve root grafting of her right brachial plexus C7 and C8.

At 14 months of age, 5 months post-surgery, progress in the functional use of her right arm slowed despite ongoing physical therapy. Her family was concerned about the limited movement in their daughter's right arm. Their treatment goals were for her to be able to use her right arm more freely, use both hands during play, and gain strength to improve her participation in functional tasks such as dressing, bathing, getting herself ready (brushing her teeth, moisturizing her skin, and doing her hair), toileting, daily chores, and keeping up with her siblings and peers.

When her progress plateaued, she was unable to raise her right arm above 90° with her elbow straight (Figure 1). Her shoulder and elbow passive range of motion were within functional limits. An imbalance of muscle activation was evident, as she could not isolate shoulder flexion or abduction without stabilization of her elbow. Through clinical observations and palpation, it was identified that she was activating her deltoid, pectoralis major, teres major, and bicep muscles simultaneously when asked to raise her right arm. Additionally, her biceps, with brachioradialis and brachialis, overpowered her triceps in strength as noted when she could not maintain elbow extension when elevating her shoulder beyond 90°. Her elbow flexors and shoulder internal rotators dominated her elbow extensors. This posture, also named the “trumpet sign,” develops from a movement pattern as if playing a trumpet. It is a common marker for children with NBPP caused by muscle imbalances and/or contractures. Because of this coactivation of the agonist and antagonistic muscles simultaneously, this child had an inability to isolate specific muscles and movements, particularly shoulder elevation (flexion or abduction) with her elbow extended; therefore, she had less available active range of motion to strengthen in more functional positions (Figure 1). She was an excellent candidate for the addition of dynamic elbow bracing to her therapy sessions and daily routine. The Table includes clinical measurements of selected shoulder, forearm and elbow active range of motion, strength, and shoulder function and arm appearance with a custom dynamic elbow brace off and on with her involved upper extremity.

TABLE 1 - Assessment Summary

Clinical Measurements and Functional Presentation	Brace Off	Brace On With Extension Assist; Tension of 1 in-lb or 0.113 Nm
Active range of motion (goniometric measurement)
Shoulder flexion	0°-85°	0°-160°
Shoulder abduction	0°-85°, elbow flexed 90°	0°-160°, elbow flexed 10°
Elbow extension	−20°	−10°
Forearm supination	Neutral	0-25°
Manual muscle testing (MMT), Florence Kendall's manual muscle grading 0/5
Shoulder flexion/abduction	1/5	2+/5
Biceps	3/5	3/5
Triceps	1/5	2/5
Wrist flexors	2+/5	2+/5
Active Movement Scale (AMS), Curtis et al¹⁷ grading 0-7
Upper trunk: shoulder flexion/abduction	3	6
Elbow flexion	7	7
Middle trunk: elbow extension	3	5
Lower trunk: wrist flexion	5	5
Modified Mallet Scale³ (evaluation of shoulder function and arm appearance) (Kozin⁷)
	16/25	20/25

INTERVENTION

Rehabilitation began at 2 weeks of age through the local early intervention program, 2 times per month, and increased to weekly physical therapy sessions at 6 months. As described previously, she had surgical neurolysis and nerve root grafting at 9 months of age. Five months post-surgery, she began to demonstrate little to no gains in her strength despite receiving physical therapy and complying with a daily home program. Integrated with rehabilitative management, an elbow immobilizer was introduced when this plateau was observed. At 18 months of age, a custom dynamic elbow brace was implemented after which new functional gains emerged.

The custom dynamic elbow brace used in this study was fabricated by UltraFlex Systems with the UltraFlex ONE²² joint and custom-molded brace made with high-density polyethylene, foam, and straps (Figure 2). The UltraFlex ONE²² joint has 3 significant properties including static progressive mobilization to improve passive range of motion, dynamic assists to facilitate concentric or eccentric muscle function and improve proprioception, and limits to control joint motion. The joint is bidirectional, offers adjustable tension (0-30 in-lb/0-3.4 Nm) and is easily reversible for flexion and extension. There are several comparable pediatric static progressive or dynamic elbow orthoses, for example, the Mackie Hinge Elbow Brace²³ through Ortho Innovations, the Advance Dynamic Elbow Brace²⁴ by Joint Active Systems, the Pro-Glide Elbow Dynamic Splint²⁵ by DeRoyal, the Elbow Dynasplint System,²⁶ and Progress Elbow Hinge Orthoses²⁷ by North Coast. The Hinged Elbow Wrap²⁸ through Benik and the Bamboo Brace²⁹ also apply these principles.

This child wore her custom dynamic elbow brace a minimum of 3 hours each day with her family's support. During these 3 hours, she was active playing with her siblings and complied with a daily 30-minute home exercise routine. Her home exercise program consisted of reaching tasks above her head in front of her and out to the side during various toddler activities with use of manipulatives, songs, and games. Her wear schedule and home exercise program were monitored using a calendar log. Her progress was assessed and documented during weekly physical therapy home visits. During therapy, the adaptability of the brace allowed its use in several effective ways. The brace was used as a custom fit immobilizer to support her elbow in full extension and target strengthen by isolating her deltoid/shoulder musculature during open and closed chain activities. Building shoulder stability and providing proprioceptive input through joint compression/weight-bearing activities was another advantage with the use of an elbow immobilizer. The brace was also used with the elbow joint unlocked adding a dynamic extension assist with tension of 1.0 in-lb or 0.113 Nm to facilitate her triceps. With the active assist for her triceps, she maintained elbow extension during active shoulder elevation activities, dampening the overpowering strength of her biceps and shoulder internal rotators. She engaged in shoulder-strengthening activities with the goal to achieve functional shoulder elevation with elbow extension. And finally, the orientation of the bidirectional hinge was adjusted to add tension with a dynamic flexion assist to target triceps strengthening, encouraging this child to actively extend against the flexion resistance.

OUTCOMES

The outcomes aligned with the principle of providing stability to increase mobility. With her elbow immobilized in extension, she had greater active shoulder flexion range of motion, which allowed her to isolate and strengthen her shoulder musculature. By immobilizing her elbow flexors, she achieved an increase in active shoulder flexion and abduction to 150°, the difference of 65° compared with without the immobilizer. The added available range of motion enabled her to further strengthen her subscapularis, teres major, deltoid, latissimus dorsi, trapezius, and rhomboid muscles. Without the immobilizer, she could only achieve 85° of active shoulder flexion. The dominance of her elbow flexors and shoulder internal rotators during functional tasks prevented or limited the contribution of these other muscles thereby restricting their development. Assisted concentric and eccentric controlled movements provided by the custom dynamic elbow brace facilitated useful and functional movement patterns. Compensatory or substitute movements, which perpetuated muscle weakness of her shoulder girdle, were negated. This child achieved active shoulder range of motion of 160° when wearing the custom dynamic elbow brace, unlocked with the extension assist at 1.0 in-lb of tension, compared with 85° without the brace (Table and Figure 1). This available active shoulder range of motion when wearing the dynamic elbow brace provided opportunities for focused muscle activation, development of motor control, and greater functional mobility of her involved upper extremity. When wearing the dynamic elbow brace with the extension assist, results of strength testing of her shoulder flexion/abduction improved, and when applying tension of 1.0 in-lb with a flexion assist, she developed her triceps strength. Additionally, in the evaluation of shoulder function and arm appearance using the Modified Mallet Scale, her score increased from 16 to 20 (Table). The results validated the benefit of using dynamic bracing for this child with functional passive range of motion and deficits including muscle weakness, muscle imbalance, cocontracting muscles, and poor active motor control. Significant functional change was observed and was relevant to her family's goals.

DISCUSSION (ADDITION TO EVIDENCE-BASED PRACTICE)

Findings confirmed that with implementation of a custom dynamic elbow brace with active-assisted mobility, this child achieved greater active shoulder range of motion while facilitating a more optimal position to allow targeted strengthening (Figure 1). The practical design of the custom dynamic elbow brace with a bidirectional hinge, adjustable tension, and locking properties provided therapeutic versatility including immobilization, active-assisted controlled movements, and resistance exercises. These features facilitated efficient and functional muscle activation patterns, negating compensatory or substitute movements. The opportunities for focused muscle activation succeeded improvements in active range of motion, strength, development of motor control, and functional mobility of her involved upper extremity.

In summary, given the plateau in her progress and prevailing muscle imbalances prior to implementation, introducing a custom dynamic elbow brace daily and during physical therapy attributed to this child's functional gains. While therapists and families cheer when their child's muscle strength is returning and they see the bicep muscle belly develop, it is important to understand the principles of nerve and muscle recovery to evaluate and treat the likely secondary abnormalities. The benefits, as evidenced in the results of improved active range of motion, strength, and function of this child's involved shoulder and elbow, have substantiated the importance of developing both the dynamic and stabilizing function of muscles. In this case, the application of a custom dynamic brace was an effective therapeutic tool and compelling adjunct to this child's comprehensive treatment program. The development of treatment protocols using dynamic bracing for recovery of functional use of the involved extremity should be strongly considered for regular implementation in physical therapy management of children with NBPP.

While success was apparent with this child, each child may not achieve the same value, possibly due to severity of injury, specific impairments, timing, intolerance or availability of the brace, including cost. Potential benefits of a dynamic brace for other children may include the treatment of joint stiffness, soft tissue contractures, range of motion limitations, and spasticity; the gentle and consistent tension prevent excessive force. The brace provides a low-load and prolonged passive stretch to soft tissues by increasing the dosage through a graded system without significant pain or tissue damage.

Using the brace also promoted muscle reeducation and biofeedback with cognitive awareness for isolated motor control of specific muscles. The concept of learning more effective movement patterns, with the potential for improved carryover without the brace, may be critical for successful outcomes and should be studied. Evidence-based research to support the effectiveness of combined treatment strategies, for example, use with neuromuscular electrical stimulation, could also be considered. And finally, the analysis of child satisfaction and quality of life, when using a custom dynamic brace as an adjunct to therapies for children with NBPP, is important for future research.

REFERENCES

1.Foad S, Mehlman C, Foad M, Lippert W. Prognosis following neonatal brachial plexus palsy: an evidence-based review. J Child Orthop. 2009;3(6):459–463.

Cited Here |
Google Scholar