Term
| Define muscular dystrophy, myopathy and neuromuscular disease |
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Definition
• Muscular dystrophy - a group of inherited disorders characterized by progressive muscle weakness due
to primary degeneration of muscle fibers
• Myopathy - a primary disease of muscle
• Neuromuscular disease - a disorder that results in muscle weakness and affects some part of the motor
unit: the anterior horn cells, peripheral nerve, neuromuscular junction or the muscle itself |
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Term
| Discuss the epidemiology of Duchenne Muscular Dystrophy (DMD) and how it is inherited |
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Definition
• genetically determined - an X-linked disorder, sons inherit the disease from asymptomatic mothers
• onset is insidious, usually demonstrating symptoms before 3 y/o, with progressive weakness that begins
in the proximal muscles |
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Term
| List the mechanisms for diagnosing DMD |
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Definition
• usually between 3-5 y/o
• parents usually take child to MD due to changes in child’s gait, increased falls and clumsiness, difficulty in
climbing stairs and getting up from the floor, c/o fatigue or inability to keep up with peers during play |
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Term
| State the three indicators of DMD noted in muscle biopsy |
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Definition
1. fiber necrosis
2. fatty infiltration
3. proliferation of connective tissue |
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Term
| Name the protein lacking in DMD |
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Definition
• dystrophin - a protein found in the surface membrane of skeletal muscle cells
• lack of dystrophin results in increased permeability in the cells
• allows for increased levels of intracellular calcium, which activates several proteolytic enzymes
resulting in cell destruction |
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Term
| Describe the three categories of signs and symptoms noted in a physical examination |
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Definition
1. gait abnormalities
• frequent falling
• waddling gait
• toe walking
• clumsiness
• difficulty getting up from floor
2. pseudohypertrophy
3. weakness
• begins proximally
• progressive |
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Term
| Name the three phases of DMD |
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Definition
1. early
2. transitional
3. non-ambulatory |
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Term
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Definition
| • increase size in muscle due to fatty infiltrate and connective tissue, not strength |
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Term
| State which muscles commonly undergo pseudohypertrophy |
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Definition
• gastrocnemius
• quadriceps
• tongue
• deltoid
• infraspinatus
• forearm extensors |
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Term
| Describe the development of toe walking in DMD |
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Definition
• early weakness in the hip and knee extensors results in an attempt to align the center of gravity anterior
to the knee joint and posteriorly to the hip joint
• results in increased lumbar lordosis, but maximal stability at these joints
• toe walking is initially a compensation due to forward weight shift required to align gravity anterior to knee
joint and posterior to hip joint
• as disease progresses, plantarflexion contractures will increase toe walking |
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Term
| Describe the postural compensations used to prolong ambulation |
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Definition
• weakness progresses with marked postural adjustments and functional losses generally 6-12 y/o
• child may be fitted with AFOs or long leg braces to assist with ambulation |
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Term
| Describe the progression of weakness and which muscle groups are affected first |
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Definition
• progresses proximal to distal
• first noticed in
• trunk
• neck flexors
• abdominals
• upper extremity
• shoulder girdle stabilizers
• deltoids
• biceps
• lower extremity
• hip abductors
• knee extensors
• tibialis anterior and peroneals |
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Term
| Define and describe Gower’s sign |
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Definition
• gower’s sign - distinctive behavior of boys with DMD when getting up from the floor due to weakness of
hip and knee extensors
• characterized by pushing up from prone into bear standing and then walking hands up the legs in order to
erect the trunk |
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Term
| Name the indicators that signal the end of independent ambulation and when that generally occurs |
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Definition
• the inability to stand from the floor or to climb stairs along with frequent falls usually signals the end of
independent walking
• when knee extension lag in sitting and hip extension lag in prone are combined for greater than 90*,
independent walking will cease in a few months
• total loss of ambulation often occurs by 12-13 y/o |
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Term
| Name the muscles most likely to develop contractures and the impact of those contractures |
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Definition
• plantarflexors & inverters in foot
• problems with ambulation and getting shoes on
• hip flexors
• problems with ambulation and transfers
• knee flexors
• problems with ambulation and transfers
• elbow flexors
• problems with dressing, bathing, grooming, reaching
• wrist and finger flexors
• problems with feeding, gripping, hand functional activity
• forearm pronators
• problems with feeding, UE function |
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Term
| Know the recommended method for stretching the iliopsoas, IT band and TFL |
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Definition
• IT band tightness due to increased BOS with ambulation
• recommended stretching in positions to promote hip and knee extension and hip adduction
• prone position, position the hip in abduction, move to maximum hip extension, then bring hip into
adduction
• extending the knee will provide a better stretch to the IT band and TFL
• splinting to slow progression of contractures |
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Term
| Recognize the impact of scoliosis in patients with DMD |
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Definition
scoliosis tends to develop as the trunk muscles become weaker and the child spends more time sitting
and less time standing
• results in positional scoliosis with significant curves noticed after 11 y/o
• can significantly decrease respiratory capacity
• makes positioning and transfers difficult
• can compromise functional use of arms
• an orthosis can be used to aid in positioning and decrease scoliosis |
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Term
| Discuss the impact of strengthening and fatigue in DMD |
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Definition
• overexertion, exercising at maximal levels and immobility are detrimental
• focus on abdominals, hip extensors & abductors, knee extensors, scapular stabilizers and triceps
• encourage walking or standing 2-3 hours/day
• recreational activities such as bike riding and swimming for aerobic conditioning and strengthening |
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Term
| Discuss the focus of PT evaluation and treatment |
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Definition
• evaluate to get baseline
• work on function
• ADLs
• transfers
• ambulation
• assistive devices
• ROM
• cardiopulmonary status
• family education
• general goals
• prevent deformity
• prolong functional capacity
• facilitate the development and assistance of family support
• provide self-care adaptations
• control pain, if necessary |
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Term
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Definition
| • important for child to remain active as long as possible - immobility is detrimental |
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Term
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Definition
• AFOs may be used to slow progression of heelcord contractures while child is ambulatory
• AFOs or night splints, with or without knee immobilizers, during sleep
• long leg braces to provide stability while walking
• abdominal bracing once weakness progresses to trunk |
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Term
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Definition
• breathing exercises during tx and HEP
• aerobic activities such as swimming and bike riding
• blowing games, playing wind instruments, singing, etc to promote respiration
• teach child to combine inspiration with flexion movements and expiration with extension
movements
• decrease tightness of chest wall through active and passive rotation/counter-rotation and
stretching
• postural drainage and percussion |
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Term
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Definition
• feeding aids
• commode chair and urinal
• bath or shower chair and long-handled bath brush
• adaptive clothing and adult briefs
• computers for schoolwork and play |
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Term
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Definition
| • may need sliding boards or mechanical lifts for safety |
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Term
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Definition
• difficulty changing positions during sleep and moving in bed
• need a regular positioning program of turning 3-5x during the night to promote comfort and
relieve pressure areas; hospital bed with pressure-relieving mattress an option |
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Term
| Name the primary cause of mortality in DMD |
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Definition
• most die in late teens to early twenties due to respiratory failure/infection or cardiorespiratory insufficiency
• start losing vital capacity at 8-9 y/o
• elevate HOB to ease respiratory distress that can occur during sleep |
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