Study : Use of the Dynamic Movement Orthosis to Provide Compressive Shoulder Support for Children With Brachial Plexus Palsy

Children with obstetric brachial plexus palsy often present with shoulder alignment issues. Shoulder subluxation may occur as a result of shoulder girdle muscle weakness and overstretching of the ligamentous support structure around the glenohumeral joint. Optimal alignment and support of the glenohumeral joint is essential for active functional shoulder movement and distal control. Shoulder support options are limited for children, because materials may not be suitable for daily wear and compliance is often poor. The purpose of this case study was to evaluate the effectiveness of a custom-fitted shoulder orthosis, the Dynamic Movement Orthosis (DMO), and its ability to support and improve upper limb function during active wear. The Wolf Motor Function Test assesses 17 tasks (2 strength based, measured by weight lifted and grip, and 15 function based, measured using time to completion). This test was used to objectively quantify active shoulder and elbow movements with and without the use of a custom-fitted DMO. This case study suggests that the DMO supported the shoulder during functional task and optimized active strength distally in the wrist and elbow. (J Prosthet Orthot. 2011;23:159 –164.) KEY INDEXING TERMS: shoulder orthosis, brachial plexus palsy, shoulder weakness, shoulder subluxation, shoulder brace, obstetric brachial plexus palsy Obstetric brachial plexus palsy (OBPP) is a complication that may occur during a difficult delivery; however, delivery by caesarian section does not exclude the possibility of a birth palsy. The incidence of OBPP is 1 per 1,000 live births. The most common type of OBPP involves the upper trunk (C5-C6), sometimes in combination with a C7 injury. There are fewer injuries of the entire plexus (C5-T1) and rarely the lower trunk (C8-T1) can be involved. During the early years of life, neurological recovery is an important factor in determining a child’s active range of motion of his/her arm. After an OBPP, an infant is generally seen for occupational or physical therapy on a regular basis to improve muscle strength in recovering muscles, prevent joint deformity, and monitor the baby’s developmental milestones. Muscle imbalances and incomplete or delayed nerve regeneration can pose serious secondary upper limb concerns. A common problem seen in infants with OBPP is shoulder weakness, glenohumeral joint deformity, contractures, and capsular tightness. In addition, shoulder dislocation, subluxation, or instability can occur about the glenohumeral joint. Glenohumeral stability plays an integral role in the function of the shoulder. Shoulder weakness or subluxation decreases the ability to stabilize the kinetic chain for active use of the arm distally. Providing stability to the shoulder post-OBPP has historically been a challenge in the child with significant weakness. If the axillary nerve is involved, the child demonstrates limited active movement into humeral flexion and abduction. The axillary nerve branches off the posterior cord of the brachial plexus and carries the nerve fibers from C5 and C6. It supplies the muscles of the shoulder, including the rotator cuff and the deltoid. Deltoid atrophy due to axillary nerve involvement can be seen by observation, noting the prominence of the acromion. There may also be signs of shoulder dislocation or subluxation, which is seen with increased spacing between the humeral head and acromion. In a normal shoulder, the alignment of the humeral head within the glenoid fossa is supported and maintained by an intricate muscle balance, the shape of the glenoid fossa, and rotator cuff muscles; which is reliant on the integrity of the sensory and motor tracts. Weakness of the shoulder girdle and inability to actively lift the arm places the arm in a dependent position with potential for shoulder subluxation. Limited ability to abduct or flex the shoulder against gravity may be due to weakness or paralysis of the deltoid and supraspinatus. Any contraction of the muscles distally may be less effective due to the decreased proximal stability of the AUDREY YASUKAWA, OTR/L, is affiliated with LaRabida Children’s Hospital, Developmental and Rehab Services, Chicago, Illinois. PATRICIA MARTIN, PT, is affiliated with Cleveland Clinic Children’s Hospital for Rehabilitation, Therapy Services, Cleveland, Ohio. ARTHUR GUILFORD, CPO, is affiliated with G.A. Guilford & Son Ltd., Cleveland, Ohio. SHUBHRA MUKHERJEE, MD, is affiliated with Physical Medicine and Rehabilitation, Rehabilitation Institute of Chicago, Northwestern Feinberg School of Medicine, Chicago, Illinois. Disclosure: The authors declare no conflict of interest. Copyright © 2011 American Academy of Orthotists and Prosthetists. Correspondence to: Audrey Yasukawa, OTR/L, Chief of Occupational Therapy, LaRabida Children’s Hospital, 6501 S. Promontory Drive, Chicago, Illinois; e-mail: ayasukawa@larabida.org 159 Volume 23 • Number 3 • 2011 shoulder. As the elbow attempts to flex or extend, the ligaments/tendons attached to the scapula and humerus may become further overstretched and weak. Tension on the taut joint capsule, with overstretched tendons and ligaments, over time, can further increase the weakness of muscles controlling the elbow, forearm, and hand. Overlengthened muscles do not have an optimal length-tension curve, decreasing their ability to generate force during a contraction. There are numerous studies with the adult stroke population documenting the efficacy of reducing shoulder subluxation with different types of supports for the involved hemiplegic shoulder. There are limited data supporting the effectiveness of bracing children with shoulder subluxation. However, a case study described a custom-fitted, child-sized shoulder support that reduced subluxation and maintained alignment through extended periods of the day. The shoulder support was worn directly on the skin to provide maximum support and was made from a Velcro-compatible fabric, with a perforated neoprene. The disadvantage of the custom shoulder brace was that a caregiver was required to don the brace, and the patient was unable to independently apply the straps and adjust tension for optimal support. The perforated neoprene material was heavy, and during the summer months, the brace retained heat and perspiration. Similar to the custom-fitted brace, the Dynamic Movement Orthosis (DMO) is made from a Lycra material, which is more breathable and can be treated to wick away perspiration. Each panel or section of the Lycra material is measured using specific tensions and directions of pull to support the child’s need for maintaining biomechanical alignment. The shoulder DMO is measured to provide a snug fit and to support the shoulder girdle and arm, and to improve the control of movement and function. The case study described will evaluate the custom-fabricated DMO and the efficiency of movement while wearing the DMO.