Rehabilitation Management of the Patient With Duchenne Muscular Dystrophy

Multidisciplinary assessment across the International Classification of Functioning, Disability, and Health and care continuum remains important in guiding rehabilitation interventions. Assessment tools recommended in the original (2010) Care Considerations remain supported and expanded via newly developed tools (Tables 3 and 4). Impairment-level measures include passive ranges of motion (ROM) and the assessment of alignment and posture, which is critical in monitoring the success of musculoskeletal management and identifying needs for additional physical therapy (PT), occupational therapy (OT), orthotic intervention, serial casting, seating system modification, supported standing, and adaptive equipment. Standardized functional assessments for DMD have been expanded with the establishment of validity, reliability, predictive potential, and minimal clinically important differences, which are described in detail in the 2018 DMD Care Considerations.^3,–5 These assessments should be used across the life span (Table 3).^{32,41,58,–66} Use of the same measures over time, including new assessments as appropriate, is recommended to monitor change and support anticipatory management. Measurement of pain,^67,–73 fatigue,⁷⁴ disability,⁷⁵ participation, quality of life,^69,75,–77 and patient-reported outcomes^32,78,–84 are important as is the increasing use of activity monitoring.^59,60,63 Occupational therapist assessment of learning, attentional, and sensory processing differences, fine motor function, and activities of daily living (ADL) should begin early, guiding intervention and optimizing success. Multidisciplinary assessment across the International Classification of Functioning, Disability, and Health should occur at least every 6 months, with more frequent assessment being triggered by concern, change in status, or specific needs as supported by professional standards of care.^85,86 

Comprehensive, anticipatory, preventive rehabilitation management is focused on protecting fragile muscles; preserving and maintaining optimal strength; minimizing the progression of weakness when possible; preventing and minimizing progressive contracture and deformity; supporting optimal cardiorespiratory care and function; optimizing energy efficiency and energy conservation; providing adaptive equipment and assistive technology; maintaining skin integrity; preventing and minimizing pain; supporting function, functional independence, and participation at school, work, and in family and social life; and optimizing quality of life.^{1,–3,6,–9,20,–31,108} 

A multidisciplinary rehabilitation team is required that includes physicians, physical therapists, occupational therapists, speech-language pathologists, orthotists, and providers of durable medical equipment who coordinate with those in pulmonary medicine, orthopedics, cardiology, neurology, genetics, social work, psychology, endocrinology, nutrition, and gastroenterology. Direct skilled PT, OT, and speech-language therapy, based on individual assessment, are provided in outpatient, home, and school settings and in inpatient settings during hospitalizations and should be continued throughout adulthood.

Anticipatory preventive musculoskeletal management is focused on preserving muscle extensibility, joint mobility, and symmetry to prevent and minimize contracture and deformity and should be a component of care at all stages.^{1,–3,7,–9,20,–22,24,–31} Joint contractures and diminished muscle extensibility in DMD result from interacting factors, including a lack of full active joint ROM, static positioning, and imbalanced muscle weakness across joints.² Fibrotic changes in the muscle begin with early fibrosis in the newborn period, revealing the importance of early preventive management of muscle flexibility and extensibility.^{9,13,–16,20,–22,24,–31,85,86,108,109} Effective maintenance of joint ROM, muscle extensibility, and prevention of contracture and deformity requires multiple coordinated interventions, including active and/or active-assisted elongation; daily passive stretching of joints, muscles, and soft tissues at risk for tightness and those identified via assessment; prolonged elongation; and support of optimal positioning throughout the day with splinting, orthotic intervention, standing devices, custom seating in mobility devices, and adaptive equipment.^{1,–3,7,–13,15,16,20,–22,24,–31,33,110,–112} 

Stretching to prevent and minimize contractures should be done a minimum of 4 to 6 days per week for joints and muscle groups known to be at risk for hypoextensibility and those identified via assessment (Tables 1 and 2).² When stretching, providers should include manual therapy techniques, avoid the elicitation of pain, and establish a preventative stretching program before decreases in passive ROM occur, with direct PT and OT accompanied by support of optimal positioning and the use of splinting and orthotic intervention, custom seating systems, supported standing, and adaptive equipment. Preventive stretching of lower extremities (LEs) should be initiated early in the ambulatory phase and continued through adulthood. Preventive stretching of upper extremities (UEs) and the neck becomes increasingly important in nonambulatory stages and throughout adulthood. Increased risk areas for contracture and deformity in adults with DMD (Tables 1 and 2) necessitate detailed assessment and intervention over time. The maintenance of chest wall mobility is important in respiratory management and the prevention of scoliosis. Local care should be augmented by guidance from specialists every 4 to 6 months.^{1,–3,7,8,11,–13,15,16,20,–22,24,–31,33,110} 

The prevention of contractures and deformity requires preventive splinting and orthotic intervention, positioning, supported standing programs, and the use of adaptive equipment and assistive technology in addition to manual stretching programs (see Supplemental Figs 2–11) (Tables 4 and 5).^{1,–3,7,8,13,15,16,20,–22,24,–31,108} 

Resting or stretching ankle-foot orthoses (AFOs) are necessary, with nighttime use having been shown to prevent and minimize progressive plantarflexion contractures, and are appropriate throughout life.^{2,3,7,11,13,18,24,28,–31,109,113} AFOs should be custom molded, fabricated for comfort and optimum foot-ankle alignment. They are typically best tolerated if started preventively at young ages. Blanket lifter bars may ease bed mobility, increasing tolerance of nighttime AFO use. If nighttime tolerance cannot be achieved, the use of stretching AFOs during nonambulatory portions of the day is encouraged. Daytime AFO use can be appropriate for full-time wheelchair users, extending into adulthood. Lower-profile orthoses may be considered for full-time wheelchair users to control plantar varus if adequate medial-lateral positioning is maintained and adequate dorsiflexion is supported by wheelchair footrests. Knee-ankle-foot orthoses (KAFOs) (eg, long leg braces or calipers) for supported standing, limited ambulation for therapeutic purposes, and the prevention of contracture and deformity in late-ambulatory and early nonambulatory stages^{11,13,20,21,27,28,44,–54} are evolving and may not be tolerated at night.¹³ Adjustable knee extension splints can be considered for assistance in maintaining knee extension range in nonambulatory individuals. Comfortable support of neutral LE positioning in bed helps minimize contracture. The use of resting hand splints, stretching gloves, and oval-8 finger splints is appropriate, continuing into adulthood for stabilization, support, and musculoskeletal management. (Supplemental Fig 2).

Supported standing devices for individuals with no or mild LE contractures are necessary for late-ambulatory and early nonambulatory stages, including standers and stand-and-drive motorized wheelchairs, extending benefits previously reported with the use of KAFOs.^{2,3,7,8,13,16,28,44,–53,112} Supported standing for prolonged passive elongation of LE musculature should be considered when standing and walking in good alignment become difficult. The importance of initiating the preventive use of supported standing before the development of contractures should be emphasized.¹¹² Many advocate for the continued use of supported standing devices and a powered stand-and-drive motorized wheelchair into late-nonambulatory stages and throughout adulthood if contractures do not limit positioning and if devices are tolerated. Motorized stand-and-drive wheelchairs obviate the need for transfers to use supported standing, decreasing the risk of falls and increasing the number of hours per day of functional, comfortable, supported standing (Supplemental Fig 5).

Serial casting^55,56 can be considered when stretching and orthotic use have not maintained adequate ROM and/or when surgery is not preferred or chosen.^55,56 Serial casting for ambulatory individuals is used only if ambulation remains possible while casted with sufficient quadriceps strength to avoid compromising ambulation and losing function.⁵⁵ In nonambulatory individuals, the risk of functional loss is less, but cast weight may compromise transfers, necessitating lift use, and may be contraindicated with severe contractures. Skin integrity and osteoporosis must also be considered. An experienced team is required for the successful use of serial casting.

The prolongation of ambulation for 2 to 4 years has historically been reported with KAFOs, with or without accompanying LE surgery, and associated with decreases in scoliosis and LE contracture, although with contextual qualifications, including individual, family, and team preferences, and greater success with experienced teams and in the absence of obesity.^{7,13,28,44,–53} Individuals with DMD, who are now walking longer with glucocorticoids even without KAFOs, have differing height and body configurations at ambulation loss (decreased height, increased BMI, and increased relative hip abduction and/or external rotation versus spinal extension). These differences present challenges in wearing KAFOs, including an increased risk of fracture as a result of a higher risk of falls. Moreover, technological options, including increasingly routine use of stand-and-drive motorized wheelchairs, may be more common than KAFOs to maintain supported standing mobility. However, reports of KAFO use with glucocorticoids prolonging ambulation to even older ages,⁵⁴ family satisfaction in spite of challenges,¹¹⁴ and situations in which KAFOs are the only means of supported standing suggest that KAFOs continue to be an appropriate option in some contexts. Rapidly advancing technology in robotics offers potentially improved future options. KAFO use should be viewed as therapeutic rather than functional, with care taken to support safety to minimize the risk of falls, and not used exclusive of motorized mobility, which is typically provided simultaneously or earlier for safe, optimal, functional independence; mobility; and participation in all settings.

Physical therapist collaboration with those in orthopedics to prevent falls and fractures and maintain or regain ambulation after a long bone fracture is increasingly emphasized.¹¹⁵ Extended ambulatory capacity, coupled with the risk of low-trauma fractures,⁵⁴ increases the importance of fall prevention, including fall risk assessment across settings, pool shoes for fall prevention when walking on slippery surfaces, and the early use of lift and/or transfer equipment, especially in bathrooms, where transfer challenges compromise safety. Rapid appropriate team management of long bone fractures with associated rehabilitation is essential and may include the temporary use of assistive devices and other types of support to minimize the risk of loss of ambulation and prevent accelerated contracture and/or deformity.^4,115 

OT is important for early assessment and intervention for learning, attentional, and sensory processing issues, which are increasingly understood as being important in DMD (Table 6).

Physical therapists prescribe, monitor, and guide exercise in DMD on the basis of understanding potential effects of activity and exercise on dystrophin-deficient muscle. Concern about exercise hastening the progression of weakness in DMD is longstanding^116,–136 based on pathophysiology, including the risks of contraction-induced muscle injury and exercise-induced structural damage^{117,–119,121,123,–126} related to strength, the duration of contraction, and the load imposed.^{116,–121,123,–126,128,131,132} Other concerns include nitric oxide synthase dysfunction leading to increased ischemia during exercise¹²⁷ and cardiac concerns, including a lack of correlation between skeletal and cardiac muscle involvement^57,137,138 with moderately to severely reduced exercise capacity, as measured by cardiopulmonary exercise testing, even in the presence of normal or mildly impaired gross motor function and capacity.^139,140 The balance between beneficial versus harmful effects of muscle activity are not fully understood. Certain amounts of muscle activity are assumed to be beneficial in preventing disuse atrophy, maintaining residual strength, providing or maintaining potential trophic influences of active movement, and maintaining functional status and flexibility,^{2,3,128,129,132,134} but eccentric muscle activity and maximal- or high-resistance exercise are believed to be detrimental^{2,3,123,–126,128,132,–134} and inappropriate across the life span because of potential contraction-induced muscle-fiber injury. Specifics regarding the optimal type, frequency, and intensity of exercise in DMD are not definitively known.^{7,22,33,74,116,–136,139} Participation in regular, gentle aerobic functional activity, such as aquatics, cycling, and safe recreation-based activity, is recommended by some, especially early in the course of the disease, when residual strength is higher, with an emphasis on moderation, lower-duration activity, support of self-initiated rests, and the avoidance of overexertion and overwork weakness.^{2,3,7,74,116,–136,139} Aquatics, with potential benefits for aerobic-conditioning respiratory exercise and support of gravity-minimized movement, is highly recommended for the early ambulatory through nonambulatory stages and into adulthood as long as it is medically safe.^{2,3,128,132,134} Cycling is recommended as a submaximal aerobic form of activity, with benefits of assisted cycling recently reported (Supplemental Fig 3).¹⁴¹ 

Fibrosis (beginning in the newborn period, before extensive cell necrosis),¹⁰⁹ the proliferation of connective tissue, and increased stiffness, increases loads (resistance) against which muscles must work, further taxing contractile units and potentially contributing to ischemia and vascular and structural impediments to regeneration. The role of active movement, positive or negative, on the fibrotic process and vascularity is not clear.

Individualized assessment and monitoring of activity levels is important. Significant muscle pain or myoglobinuria in the 24-hour period after a specific activity is a sign of overexertion and contraction-induced injury, and if it occurs, the activity should be modified.² 

Cardiac concerns regarding exercise include cardiomyopathy and/or arrhythmias,^{2,4,34,–36,139,142} abnormalities of calcium regulation,³⁴ and cardiac wall movement³⁴; fibrosis³⁴; fatty infiltration³⁴; and conduction abnormalities.¹³⁸ These typically progress to dilated cardiomyopathy with arrhythmias, including ventricular tachycardia.³⁴ Early cardiac involvement can be present even before overt clinical manifestations.¹³⁹ Symptoms may not present until cardiac involvement is more advanced because of limited physical activity and a lack of correlation between cardiac and skeletal muscle involvement,^{3,132,134,139} supporting caution in prescribing exercise for individuals with dystrophinopathies, who appear likely to have a reduced exercise capacity even when functioning well. Individuals with DMD should have early referral to cardiology for the identification and preventive management of cardiomyopathy.^{2,–4,34,–36,57,142} 

AFOs are not typically indicated for use during ambulation because they tend to limit the compensatory movements needed for efficient ambulation, add weight that can compromise ambulation, and make it difficult to rise from the floor and climb stairs.^2,143 During the late-ambulatory stage, KAFOs with locked knees can prolong ambulation but with use decreased, as described.

During the early ambulatory stage, lightweight manual mobility devices are appropriate for pushing the child on occasions when long-distance mobility demands exceed endurance. In the late-ambulatory stage and/or early nonambulatory stages, an ultralightweight manual wheelchair with custom seating (Table 5) to support spinal symmetry and LE alignment and swing-away footrests is necessary and may be used in situations without access or transport for motorized mobility. A variety of motorized mobility devices, including standing mobility devices, may be used intermittently for energy conservation and independent long-distance mobility by individuals who continue to walk (Supplemental Figs 2–11).

As functional community ambulation becomes more difficult, a motorized wheelchair is advocated. Custom seating and power-positioning components for the initial motorized wheelchair are important standards of care (Table 5), with power stand-and-drive having been shown to be used more successfully if initiated before the development of contracture and deformity.¹¹² Custom seating for safety, support of optimal posture, and the prevention of contracture and deformity includes a solid seat with hip guides and a pressure relief cushion; a solid planar back with rigid lateral trunk supports; flip-down, swing-away, or removable knee adductors; and a headrest. Facial components on headrests may be needed in older individuals for adequate head support and symmetry. Swing-away or flip-up footrests facilitate transfers. Power-positioning components include power tilt and recline, power stand-and-drive, power-adjustable seat height, and separately elevating power-elevating leg rests. Elbow supports may be needed for UE support that keeps the hand on the joystick during position changes and on rough terrain. Retractable, swing-away joystick hardware and trays may be needed for access. Lights and blinkers are required for safety in evening community mobility. Ventilator holders are needed for those using ventilatory support (Supplemental Figs 2–11).

Referral to assistive technology (AT) specialists should be considered whenever function, independence, and participation are compromised, and is necessary when UE weakness affects reach, fine motor skills, and ADL. AT is helpful in optimizing fine motor skills, enhancing strategies for independence in ADL, and improving access to alternative computer, mobility, or environmental control (Table 7). Simple adaptations supporting UE function include elevated lap trays and/or desks, adaptive straws, a hands-free water pouch, and/or turntables if the hand cannot be brought to the mouth or if biceps strength is <3 in 5. More advanced AT options include motorized and nonmotorized mobile arm supports (considered at Brooke Upper Extremity Scale score ≥2), robotics, miniature-proportional joysticks, microswitches, Bluetooth capabilities, software and applications for computers, fall detection systems with built-in Global Positioning System detection, voice activation and texting systems on smartphones and tablets, and “smart home systems” that are able to interface with motorized wheelchairs.² Key pinch, microswitches, mouth call buttons, and monitoring systems are considered if hand or voice weakness precludes the use of standard call buttons. Adaptive equipment for the support of ADL, safety, and the maintenance of skin integrity include power-adjustable beds with pressure-relieving mattresses; bathing and toileting equipment; lift and/or transfer devices, including hydraulic and motorized patient lifts; ceiling lifts (hoists); slide sheets; and environmental control options (Supplemental Figs 2–11).

AT assessment and intervention are focused on optimizing function and participation across the life span, which are particularly important during transitions between functional levels and transitioning into adulthood.

Extended ambulation, the importance of energy conservation for muscle preservation and function, and increased independence into adulthood require expanded technology for mobility, a greater variety of choices for different situations, and increased AT options for mobility, driving, and community access that are instrumental in participation, employment, and avoidance of social isolation. Vehicle adaptations increase options for community access, and adapted controls may allow for independent vehicle driving. Skill development via accessible public transportation, OT driving evaluation, and future driverless cars promise ongoing increases in independence.

The early development of independent decision-making and respectful and responsible delegation skills in children with DMD, supported by the use of AT, self-advocacy skills, the hiring and directing of aides, the use of service animals, and social participation foster transitions to independent adult function.

Funding for the support of AT and support services is critical, as is the education of families about funding opportunities, including private insurance, Medicaid, Medicaid Waiver programs, Medicare, Independent Living, Vocational Rehabilitation, Supplemental Security Income, Achieving a Better Life Experience accounts, and other funding sources, which vary depending on the country, state, and local environment.

Pain, which is considered the fifth vital sign, is important to assess in all individuals with DMD across the life span.^67,–73 A more uniform assessment of pain, however, does not always lead to successful management of pain, which is an important priority in transitions to adulthood and the management of DMD in adulthood.⁷² Pain of varying types and intensities may occur in DMD. Effective pain management requires an accurate determination of the cause and may require comprehensive team management. Postural correction, orthotic intervention, PT, adaptive equipment, assistive technology, and pharmacological interventions may all be required. Adaptive equipment and assistive technology should be used to emphasize the prevention and management of pain and optimize comfortable function and movement with transfer, bathing, and toileting equipment. Power-positioning components offering positional support and change, weight shift, and pressure relief on motorized wheelchairs and beds can be used as needed to maintain skin integrity and pain prevention or relief. Providers of pharmacological interventions must consider possible interactions with other medications (eg, steroids and nonsteroidal anti-inflammatory drugs) and side effects, particularly those that might negatively affect cardiac or respiratory function. Rarely, orthopedic intervention might be indicated for intractable pain that is amenable to surgery. Back pain, especially if the patient is receiving glucocorticoids, is an indication for careful assessment for vertebral fractures.^{2,–4,144,145} 

Key anticipatory discussions should occur before a time of crisis in each of the following areas. Care team members can reassure the patient and family that rather than being evidence of disease progression, these issues provide opportunities to discuss options for optimizing management:

• plans for when stairclimbing becomes difficult;

• continuum of options for energy conservation and safe, functional, independent mobility and participation in all settings;

• fall risk assessment and prevention;

• fracture management;

• initiating supported standing;

• transfers and/or access at home, at school, at work, and in the community;

• consideration of KAFO use;

• spine surgery;

• strategies for optimizing ADL and self-feeding compromised by UE weakness or spine fusion; and

• noninvasive ventilation and tracheostomy.

As disease-modifying treatments become available, questions will emerge regarding potential increases in exercise capacity and muscle recovery, optimizing potential benefit versus damage from specific types, durations, and frequency of exercise. Robotics and AT advances are anticipated to provide ever increasing functional independence, capacity for participation, and successful musculoskeletal management, and it will be important to explore ways that these developments can be used to benefit individuals with DMD.

ADL

activities of daily living

AFO

ankle-foot orthosis

AT

assistive technology

DMD

Duchenne muscular dystrophy

KAFO

knee-ankle-foot orthosis

LE

lower extremity

OT

occupational therapy

PT

physical therapy

ROM

ranges of motion

UE

upper extremity