Duccheene muscular dystrophy Duchenne muscular dystrophy (DMD) is a severe type of muscular dystrophy. The symptom of muscle weakness usually begins around the age of four in boys and worsens quickly. Typically muscle loss occurs first in the thighs and pelvis followed by those of the arms. This can result in trouble standing up. Most are unable to walk by the age of 12. Affected muscles may look larger due to increased fat content. Scoliosis is also common. Some may have intellectual disability. Females with a single copy of the defective gene may show mild symptoms.

2.  Normal Gait Is Cyclical and Symmetric”
 subdivisions of the gait cycle delineated by foot/floor
contact use in comparing limb symmetry, measuring
outcomes, and the general characterization of overall gait
performance.

3. Normal Gait Description :
 Initial contact The moment when the foot
strikes the ground.
 Loading response Initial double support period
when the limb is accepting weight.
 Mid-stance First phase of single support
when the body advances over the stance limb ending
ahead of the stance limb as weight is transferred to
the forefoot.
 Terminal stance Last phase of single support
ending with opposite initial contact

4. Swing phase
 Pre-swing Final double support period when the
knee rapidly flexes in preparation for swing and weight is
shifted to the opposite limb.
 Initial swing 1st third of swing period where
maximum knee flexion occurs
 Mid-swing Middle third of swing
period where maximum hip flexion occurs, ending with a
vertical tibia
 Terminal swing Last third of swing
period where final knee extension achieves maximum
step length and the limb is properly positioned for weight
acceptance.

7. Calculation of Walking speed
 walking speed (m/s) = (cadence × stride length)/120
or
 step length (m) = (walking speed × 60)/cadence
 Stride length is the distance between the successive
heel contact points of the same foot. Normally, stride
length = 2 x step length.
 Cadence is the rate at which a person walk, expressed
in steps per minute. The average cadence is 100 - 115
steps/min

8. These basic outcome measures of overall gait
performance, including the timing measures previously
described and other quantities such stance/swing ratio,
are collectively known as temporal-distance or
temporal-spatial parameters.

9. Instrumental Gait Analysis(IGA)
 The specialized nature of the systems used to perform
an IGA typically requires a dedicated motion laboratory
with specialists from clinical and technical disciplines to
guide the patient through the testing procedures, make
the required physical and anthropometric
measurements, and record and process all data

10.  Analyses typically require 2 hours of patient contact
time and between 8 and 12 hours of processing and
analysis time, depending on the complexity of the
patient referral and the number of measurements
required to answer the clinical question. It is not
within the scope of this discussion to comprehensively
describe the full set of measurement tools available for
clinical gait analysis

11.  In addition to the temporal-spatial parameters
described in the last section, the primary
measurements comprising IGA are gait kinematics,
kinetics, and dynamic electromyography .

12. Gait kinematics
 Gait kinematics is a general term that refers to
measurement of the linear and angular displacements,
velocities, and accelerations of body segments
throughout the gait cycle

13.  Modern kinematic analysis systems use an assortment of
markers or targets that are attached to the subject at
strategic locations and can be tracked by specialized cameras
or electromagnetic detectors.
 The kinematic measurement system identifies the position
of the targets from multiple perspectives in three-
dimensional space using a high sampling rate (≥100 Hz) as
the subject walks through a calibrated measurement volume.
 This determines a unique trajectory for each target, which
can then be reconstructed by the computer utilizing a
kinematic link-segment model to produce a three-
dimensional animation of walking subject within the virtual
environment of the computer display.
 From this mathematical representation of the subject,
kinematic graphs and interactive reports can be produced to
facilitate the clinical analysis of the child’s gait

15. Rocking and Gait
Curves

16. Description
 The three rockers representing normal ankle function
in gait: These are the
 heel or first rocker,
 the ankle or second rocker, and
 the forefoot or third rocker.
 The lighter gray skeleton represents the beginning of
each rocker, and the arrows signify the movement that
is associated with each

17. Case

18. Bilateral A/P radiograph of the feet of the subject
described in case study. This radiograph is
commonly required when the subject presents
with pes planus i.e Flatfoot (pes planus) is a
condition in which the longitudinal arch in the foot,
which runs lengthwise along the sole of the foot, has
not developed normally and is lowered or flattened ,
to better understand the structural alignment of the
foot.

20. Aging with disability
 Aging with a disability can be an overwhelming and
alarming situation, especially for those experiencing
changes in function or health at an earlier-than-
expected time.
 These changes can also mean the difference between
living alone with minimal to no support and requiring
a more restrictive living environment, including a
move to an institutional setting, at a young age

21. Cerebral Palsy
 Cerebral palsy (CP) is the most common condition
that pediatric physiatrists will manage, although it is
not the most common reason for childhood disability
 Mortality
 Mortality for people with CP appears to be related to
severity of impairments. This is very clear in the
pediatric population, but less so for adults who have
survived into their late twenties and thirties.

25. Spina bifida

27. Spinal cord injury

28. Down syndrome

29. Williams’ syndrome (WS)
 Williams’ syndrome (WS) is caused by a gene deletion on chromosome
7.
 It is rare, occurring in 1 of 20,000live births (Devenny and colleagues
have been following a group of 15 adults with WS, some of whom have
participated in a 15-year longitudinal study on aging in adults with ID.
 The participants with WS demonstrated early and rapid decline in
long-term episodic memory not found in other adults with ID.
 Verbal short-term memory was better than their peers with ID and did
not decline with age .
 No association was found with physical or mental co morbidities.
 Because Williams syndrome has only been clearly described within the
current generation of adults, few people have been extensively studied,
and we do not yet know the causes of the apparent precocious aging
noted in this population.

31. Dystrophic Myopathies
 Muscular dystrophies are debilitating myopathic disorders
that present with muscle wasting and diffuse muscle
weakness.
 They are caused by genetic mutations, which produce
muscle fiber necrosis and regeneration, ultimately
resulting in muscle fiber loss
 Muscular dystrophies are caused by mutations of the genes
encoding for proteins important for the stability of the
sarcolemmal membrane and the maintenance of muscle
fiber intracellular homeostasis.
 They are genetically, biochemically, and clinically diverse
diseases

32. Duchenne Muscular Dystrophy
 Duchenne muscular dystrophy (DMD) is an X-linked
disorder caused by an abnormality at the Xp21 gene B
loci.
 The DMD/BMD gene occupies 2.5 million base pairs of
DNA on the X chromosome and is about 10 times
larger than the next largest gene identified to date.
 The gene coding sequence contains 79 exons. The
primary protein product, dystrophin, is localized to the
intracellular side of the plasma membrane of all
myogenic cells, certain types of neurons, and in small
amounts of other cell types

33.  Dystrophin deficiency at the plasma membrane of muscle
fibers disrupts the membrane cytoskeleton and leads to the
secondary loss of other components of the muscle
cytoskeleton.
 The primary consequence of the cytoskeleton
abnormalities is membrane instability, leading to
membrane injury from mechanical stresses, transient
breaches of the membrane, and membrane leakage
 Chronic dystrophic myopathy is characterized by
aggressive fibrotic replacement of the muscle and eventual
failure of regeneration with muscle fiber death and fiber
loss. Generally, loss of the reading frame causes complete
absence of dystrophin and a Duchenne phenotype.

34. Diagnostic Evaluation
 Those neuromuscular diseases with inherent sarcolemmal
muscle membrane injury often show significant elevations
in transaminases, aldolase, and creatine kinase (CK).
 The CK enzyme catalyzes the release of high-energy
phosphates from creatine phosphate. It occurs mainly in
muscle and leaks into the serum in large amounts in any
disorder involving muscle fiber injury.
 The CK value may be significantly elevated in early stages
of DMD and BMD, with values up to 50–100 times normal.
 Serum creatine kinase is a useful screening test. Gene
abnormalities may be identified by full gene sequencing of
a blood specimen in 99% of all patients with a
dystrophinopathy

35. Epidemiology
 The incidence of Duchenne muscular dystrophy, based
on a number of population studies as well as neonatal
screening, has been estimated to be around 1:3,500
male births

36. Onset and Early Signs
 The most frequent presenting symptoms have been
abnormal gait, frequent falls, and difficulty climbing steps.
 Parents frequently note the toe walking, which is a
compensatory adaptation to knee extensor weakness, and a
lordotic posture to the lumbar spine, which is a
compensatory change due to hip extensor weakness
 Malignant hyperthermia occurs during general anesthesia
for an unrelated surgical indication in patient
 Diagnosis is pursued in a male with an affected older
sibling

37.  There is child tripping or stumbling on a plantar-flexed
ankle or the knee buckling or giving way due to knee
extensor weakness. There is progressive difficulty getting
up from the floor with presence of a Gower’s sign
 Patients with proximal weakness involving the pelvic girdle
muscles may rise off the floor using the classic “Gower’s
sign,” where the patient usually assumes a four point stance
on knees and hands, brings the knees into extension while
leaning forward the upper extremities, substitutes for hip
extension weakness by pushing off the knees with the
upper extremities, and sequentially moves the upper
extremities up the thigh until an upright stance with full
hip extension is achieved

38. Gower sign

39.  girdle muscles may rise off the floor using the classic
Patients with proximal weakness involving the pelvic
“Gower’s sign,” where the patient usually assumes a four- point stance
on knees and hands, brings the
knees into extension while leaning forward the upper extremities,
substitutes for hip extension weakness
by pushing off the knees with the upper extremities,
and sequentially moves the upper extremities up the
thigh until an upright stance with full hip extension is achieved . A
Gower’s sign is not specific to any neuromuscular condition, but may
be seen in a variety of neuromuscular diseases, including
DMD,LGMD (Limb-girdle muscular dystrophy) SMA type III
Superior mesenteric artery syndrome (SMAS) is a digestive
condition that occurs when the duodenum (the first part of the small
intestine) is compressed between two arteries (the aorta and
the superior mesenteric artery). This compression causes partial or
complete blockage of the duodenum.

40.  Pain in the muscles, especially the calves, is a
common symptom. Enlargement of muscles,
particularly the calves.

41.  The deltoid may also be hypertrophied. patients arms
abducted to 90 degrees and externally rotated, the
hypertrophy of the posterior deltoid and infraspinatus
frequently leaves a depression between these two muscles
referred to as the “posterior axillary depression sign” in
DMD

42.  The tongue is also frequently enlarged. There is also
commonly an associated wide arch to the mandible
and maxilla with separation of the teeth, presumably
secondary to the macroglossia

43. Pattern and Progression of
Weakness
 Earliest weakness is seen in the neck flexors during
preschool years

44.  Weakness is generalized, but predominantly proximal early
in the disease course. Pelvic girdle weakness predates
shoulder girdle weakness by several years.
 Ankle dorsiflexors are weaker than ankle plantar flexors;
ankle everters are weaker than ankle inverters; knee
extensors are weaker than knee flexors; hip extensors are
weaker than hip flexors; and hip abductors are weaker than
hip adductors
 With manual muscle testing, DMD subjects exhibit loss of
strength in a fairly linear fashion from ages 5 to 13, and
measurements obtained several years apart will show fairly
steady disease progression.

45. Loss of Ambulation
 Average age to wheelchair in a DMD population not
treated with corticosteroids has been age 10, with a
range of 7–13 years. Treatment with prednisone or
deflazacort helps maintain strength and prolongs
ambulation by two years. The optimal dose of
prednisone is 0.75 mg/ kg/day up to a maximum of 40
mg/day
 All DMD subjects who took nine seconds or longer to
ambulate 30 feet lost ambulation within two years. All
DMD subjects who took 12 seconds or longer to
ambulate 30 feet lost ambulation within one year

46. Contractures
 Significant joint contractures have been found in
nearly all children with Duchenne muscular dystrophy
older than age 13
 The most common contractures include ankle plantar
flexion, knee flexion, hip flexion, iliotibial band,
elbow flexion, and wrist flexion contractures
 Significant contractures have been shown to be rare in
DMD before age 9 for all joints

47.  Spine Deformity
Reported ultimate prevalence of scoliosis in DMD subjects not treated
with corticosteroids varies from 33% to 100%
 Pulmonary Function
In DMD, absolute forced vital capacity volumes increase during the first
decade and plateau during the early part of the second decade
 Ultimately, respiratory failure in DMD is insidious in its onset and
results from a number of factors, including respiratory muscle
weakness and fatigue, alteration in respiratory system mechanics, and
impairment of the central control of respiration. Noninvasive forms of
both positive and negative pressure ventilatory support are increasingly
being offered to DMD patients nocturnally and continuously with
acceptable quality of life. Airway clearance strategies, such as the cough
assist/inexsufflator, TheraVest, or intrapulmonary percussion
ventilation (IPV) are also important pulmonary management strategies

48. Cardiomyopathy
 The dystrophin protein is present in both the
myocardium and the cardiac Purkinje fibers.
 Abnormalities of the heart may be detected by clinical
examination, electrocardiogram (ECG),
echocardiography, and Holter monitoring.
 Cardiac examination is notable for the point of
maximal impulse palpable at the left sternal border
due to the marked reduction in anteroposterior chest
dimension common in DMD.

49. Difference b/w DMD AND BMD
 BMD:
X-linked
Xp21 (reading frame maintained
Dystrophin
4–12 years (severe BMD)
ONSET. Late teenage to adulthood (mild BMD)
Loss of ambulation: >16 years
CK: 5,000 to 20,000
 Lower levels with increasing age

50. Difference b/w DMD AND BMD
 DMD:
X-linked
Xp21 (reading frame shifted
Dystrophin
Onset 2 to 6 years
Loss of ambulation: 7 to 13 yrs (no corticosteroids)
 Loss of ambulation 9 to 15 years (corticosteroids)
Blood shows:
CK: Very high (10,000–50,000)
 High AST and ALT (normal GGT)
 High aldolase

51.  Hypotonia in an 18-month-old child with
 spinal muscular atrophy

52.  Keratosis pilaris is a common skin condition, which
appears as tiny bumps on the skin. skin rash on the
extensor surface of the arm in
 Ullrich congenital muscular dystrophy with
collagen type VI abnormality