PTA 110: Functional & Applied
Anatomy
Concorde Career College
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It is not clear whether gait is learned or is
pre-programmed at the spinal cord level.
However, once mastered, gait allows us to
move around our environment in an efficient
manner, requiring little in the way of
conscious thought, at least in familiar
surroundings.
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Most fundamental human locomotion
◦ Bipedal
◦ Reciprocal movement behavior
◦ Symmetrical (displacement and timing)
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Describes important events occurring between two
successive heel contacts of same limb
Gait cycle is described as occurring between 0%
and 100% and includes 2 primary phases, the
stance phase and the swing phase
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Heel contact
◦ The instant the lower limb contacts the ground (0% of gait
cycle)
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Foot flat
◦ The period that the entire plantar aspect is on ground (8%
of gait cycle)
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Mid stance
◦ The point where the body’s weight passes directly over
supporting lower extremity (30% of gait cycle)
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The gait cycle consists of two periods:
stance and swing
◦ The stance period
 Constitutes approximately 60% of the gait cycle
 Describes the entire time the foot is in contact with the
ground and the limb is bearing weight
 Begins with the initial contact of the foot on the ground,
and concludes when the ipsilateral foot leaves the ground
 The stance period takes about 0.6 sec during an average
walking speed
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Heel off
◦ The instant the heel comes off ground (40% of gait cycle)
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Toe off
◦ The instant the toe leaves ground (60% of gait cycle)
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Push off
◦ Describes combined actions of heel off and toe off, when
stance foot is literally “pushing off” toward next step
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Weight acceptance
◦ The weight acceptance task occurs during the first
10% of the stance period
 The loading response interval begins as one limb bears
weight while the other leg begins to go through its
swing period. This interval may be referred to as the
initial double stance period and consists of the first 010% of the gait cycle
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Single Leg Support
◦ The middle 40% of the stance period is divided
equally into mid stance and terminal stance
 The mid stance interval representing the first half of the
single limb support task, begins as one foot is lifted, and
continues until the body weight is aligned over the
forefoot
 The terminal stance interval is the second half of the
single limb support task. It begins when the heel of the
weight bearing foot lifts off the ground and continues
until the contralateral foot strikes the ground
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Early swing
◦ Period from toe off to mid swing (65% of gait cycle)
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Mid swing
◦ Period when foot of swing leg passes next to foot of stance
leg (75% of gait cycle)
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Late/Terminal swing
◦ Period from mid swing until heel contacts ground (85% of
gait cycle)
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Step
◦ Events occurring between successive heel contacts of
opposite feet
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Step length
◦ Distance traveled in one step
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Step width
◦ Distance between heel centers of two consecutive foot
contacts
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Stride
◦ Events that take place between successive heel contacts of
same foot
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Stride length
◦ Distance traveled in one stride—two consecutive heel
contacts of same foot
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Cadence
◦ Also called step rate, defined as number of steps
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Walking velocity
◦ Speed at which an individual walks
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Gait cycle beginning, when heel first contacts the
ground
Center of gravity of body is at its lowest point
Ankle is held in neutral dorsiflexion
Ankle transitions toward foot-flat stance and the
ankle dorsiflexor muscles are eccentrically
activated to assist with lowering the ankle into
plantarflexion
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The knee is slightly flexed, positioned to absorb
shock of initial weight bearing
Quadriceps are eccentrically active to allow a slight
“give” to the flexed knee and help prevent the knee
from buckling
Hip extensors are isometrically active to prevent
the trunk from jackknifing forward
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Point in which the entire plantar surface of foot
contacts the ground
Loading-response phase of gait
Muscles and joints of lower limb assist with shock
absorption, as the lower extremity continues to
accept increasing amounts of body weight
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The ankle has just rapidly moved into 5-10
degrees of plantar flexion
Knee continues to flex to about 15 degrees, acting
as a shock absorbing “spring”
Quadriceps continue to function eccentrically, and
the hip extensors guide hip toward increasing
extension
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Occurs as the leg approaches vertical position
Leg is in single-limb support, as the other limb is
freely swinging forward
The ankle dorsiflexor muscles are inactive; plantar
flexor muscles are eccentrically active, controlling
the rate at which the lower leg advances over the
foot
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Knee reaches near-fully extended position
Hip abductors play an important role in stabilizing
the pelvis in the frontal plane, preventing the
opposite side of pelvis from dropping excessively
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Occurs just after mid stance as the lower leg and
ankle begin “pushing off,” continuing to propel
body forward
Begins as the heel breaks contact with the ground
Plantarflexor muscles and the Achilles tendon
stretch in preparation for propulsion
At heel off, the plantarflexor muscles have
switched their activation from eccentric to
concentric
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Extended knee prepares to flex, usually driven by
short burst of activity from the hamstring muscles
Hip continues to extend, ending in about 10
degrees of extension
Eccentric activation of hip flexors, particularly
iliopsoas, help control the amount of hip extension
that occurs
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Final event of stance phase of gait
Toe off ends when toes break contact with the
ground
Toes are in marked hyperextension at the
metatarsophalangeal joints, supported by
activation of the intrinsic foot muscles
Ankle continues plantarflexing through concentric
activation of plantarflexor muscles
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At toe off, knee is flexed 30 degrees, but
hamstrings are only minimally active
Most knee flexion arises as a result of inertia
produced, as hip is pulled into flexion
In final stage of toe off, hip is in nearly-neutral
position, with thigh nearly perpendicular to ground
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Limb Advancement
◦ Pre-swing. This interval begins with initial contact
of the contralateral limb and ends with ipsilateral
toe-off. As both feet are on the floor at the same
time during this interval, double support occurs for
the second time in the gait cycle.
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Leg begins to accelerate forward
Plantarflexed ankle begins to dorsiflex, clearing the
ground as it is advanced forward
Knee continues to flex, and hip flexors continue to
contract, pulling the extended thigh forward
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Midpoint of swing phase
Contralateral leg is in mid stance, supporting the
body weight
Ankle is held in neutral position
Knee is flexed about 50-60 degrees, helping
advance the lower limb
Hip approaches 35 degrees of flexion, continuing
to be pulled forward through concentric hip flexor
activation
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Limb begins to decelerate in preparation for heel
contact
Leg is placed well in front of body, preparing for
transition to accept body weight
Ankle dorsiflexors are activated isometrically,
positioning foot for heel contact
Knee has moved from flexed position of mid swing
to almost full extension
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Hamstrings are active eccentrically at this time to
slow rapidly extending knee
Hip flexor muscles become inactive in terminal
swing
Hip extensors decelerate forward leg progression
leg through eccentric activation
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Abductor muscles play an important role in frontal
plane hip stability
Without activation of hip abductors on the stance
leg, the opposite side of pelvis would drop under
the force of gravity, known as a positive
Trendelenburg sign
Activation of the stance leg’s hip abductors holds
the pelvis level
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Strong medial and lateral collateral ligaments of
knee provide natural stability to knee in frontal
plane
Loss of this stability may lead to issues such as
genu valgus, potentially altering normal gait
mechanics
Instability of knee may arise from impairments at
hip or foot
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While walking, subtalar and transverse tarsal joints
cooperate to transform the foot from pliable
platform at early stance to more rigid platform at
late stance
Position of supination arranges bones of foot to
their most stable position, forming rigid lever for
push-off
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Much of the lower limb control within the
horizontal plane during walking occurs at hip and
foot
During walking, the pelvis rotates in the horizontal
plane about a vertical axis of rotation through hip
joint of stance leg
Because the trunk remains relatively stationary
during walking, the lumbar spine must rotate
slightly to de-couple the rotating pelvis from
thorax
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Pelvis
◦ For normal gait to occur, the pelvis must both
rotate and tilt
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Sacroiliac Joint
◦ As the right leg moves through the swing period,
the position of the right innominate changes
from one of extreme anterior rotation at the point
of pre-swing to a position of posterior rotation at
the point of initial contact
◦ As the right extremity moves through the loading
response to mid stance, the ilium on that side
begins to convert from a posteriorly rotated
position to a neutrally rotated position. From
mid stance to terminal stance, the ilium rotates
anteriorly, achieving maximum position at
terminal stance
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Sacroiliac Joint
◦ The sacrum rotates forward around a diagonal axis
during the loading response, reaching its maximum
position at mid stance (e.g., right rotation on a right
oblique axis at right mid stance), and then begins
to reverse itself during terminal stance
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Hip
◦ Hip motion occurs in all three planes during the
gait cycle
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Knee
◦ The knee flexes twice and extends twice during
each gait cycle: once during weight bearing and
once during non-weight bearing
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Foot and ankle
◦ Ankle joint motion during the gait cycle occurs primarily in
the sagittal plane
 At initial contact with the ground the ankle is dorsiflexed
 During the loading response interval, plantar flexion occurs at
the talocrural joint, with pronation occurring at the subtalar
joint
 At the end of the mid stance interval, the talocrural joint is
maximally dorsiflexed, and the subtalar joint begins to supinate
 From the mid stance to the terminal stance interval the foot is in
supination
 Once the ankle is fully close-packed, the heel is lifted by a
combination of passive force and contraction from the taut
gastrocnemius, and the soleus
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Spine and pelvis
◦ During the swing period, the semispinalis,
rotatores, multifidus, and external oblique
muscles are active on the side toward which the
pelvis rotates
◦ The erector spinae and internal oblique
abdominal muscles are active on the opposite
side
◦ The psoas major and quadratus lumborum help
to support the pelvis on the side of the swinging
limb, while the contralateral hip abductors also
provide support
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Knee
◦ During the swing period, there is very little
activity from the knee flexors
◦ The knee extensors contract slightly at the end of
the swing period prior to initial contact. During
level walking the quadriceps achieve peak activity
during the loading response interval (25%
maximum voluntary contraction) and are
relatively inactive by mid stance as the leg
reaches the vertical position and ‘locks’, making
quadriceps contraction unnecessary
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Hip
◦ During the early to mid portion of the swing
phase, the iliopsoas is the prime mover with
assistance from the rectus femoris, sartorius,
gracilis, adductor longus, and possibly the tensor
fascia latae, pectineus, and the short head of the
biceps femoris during the initial swing interval
◦ In terminal swing, there is no appreciable action
of the hip flexors when ambulating on level
ground. Instead the hamstrings and gluteus
maximus are strongly active to decelerate hip
flexion and knee extension
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Hip
◦ The adductor magnus muscle supports hip
extension and also rotates the pelvis externally
toward the forward leg
◦ In mid stance, coronal plane muscle activity is
greatest as the abductors stabilize the pelvis. The
muscle activity initially is eccentric as the pelvis
shifts laterally over the stance leg. The gluteus
medius and minimus remain active in terminal
stance for lateral pelvic stabilization
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Knee
◦ Hamstring involvement is also important to normal
knee function. The co activation of the antagonist
muscles about the knee during the loading
response aid the ligaments in maintaining joint
stability, by equalizing the articular surface
pressure distribution, and controlling tibial
translation.
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Foot and ankle
◦ During the beginning of the swing period, the
tibialis anterior, extensor digitorum longus (EDL),
extensor hallucis longus (EHL), and possibly the
peroneus tertius contract concentrically with slight
to moderate intensity tapering off during the
middle of the swing period
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Foot and ankle
◦ At the point where the leg is perpendicular to the
ground during the swing period, the tibialis
anterior, EDL and EHL group of muscles contract
concentrically to dorsiflex and invert the foot in
preparation for the initial contact
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Foot and ankle
◦ Following initial contact, the anterior tibialis
works eccentrically to lower the foot to the
ground during the loading response interval
◦ Calcaneal eversion is controlled by the eccentric
activity of the posterior tibialis, and the anterior
movement of the tibia and talus is limited by the
eccentric action of the gastrocnemius and soleus
muscle groups as the foot moves towards mid
stance
◦ Pronation occurs in the stance period to allow for
shock absorption, ground terrain changes, and
equilibrium
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Foot and ankle
◦ The triceps surae become active again from mid
stance to the late stance period contracting
eccentrically to control ankle dorsiflexion as the
COG continues to move forward
◦ In late stance period the Achilles tendon is
stretched as the triceps surae contracts and the
ankle dorsiflexes
◦ At this point the heel rises off the ground and the
action of the plantar flexors changes from one of
eccentric contraction, to one of concentric
contraction
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Gait involves the displacement of body
weight in a desired direction utilizing a
coordinated effort between the joints of the
trunk and extremities and the muscles that
control or produce these motions
Any interference that alters this relationship
may result in a deviation or disturbance of
the normal gait pattern
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Five priorities of normal gait:
◦ Stability of the weight bearing foot throughout
the stance period
◦ Clearance of the non-weight bearing foot during
the swing period
◦ Appropriate pre-positioning (during terminal
swing) of the foot for the next gait cycle
◦ Adequate step length
◦ Energy conservation
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Infant-Child
◦ Crawling
◦ Toddler – not mature gait pattern
◦ About age 5 – mature gait pattern
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Increase in absolute stride length
Heel-toe pattern through foot flat to toe-off
Narrowing base of support
Control over terminal knee extension
Full pelvic rotation
Improved balance and postural alignment
Reciprocal arm leg gait pattern
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Older Adults
◦ Weakness, loss of ROM, decrease in sensory motor
control, decrease in balance control, postural
misalignment
 Slower walking speed – shorter step length
 Increased stance phase
 Increase step width – larger base of support for
balance
 Increase fear of falling
 Forward flexed close in visual tracking
 Encourage forward visual tracking
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Pain
Posture
Flexibility and the amount of available joint motion
Endurance - economy of mobility
Base of Support
Interlimb coordination
Leg-length
Gender
Pregnancy
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Obesity
Age
Lateral and vertical displacement of the
COG
Properly functioning reflexes
Vertical Ground Reaction Forces
Medial-Lateral Shear Forces
Anterior-Posterior Shear Forces
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In general gait deviations fall under four
headings:
◦ Those caused
◦ Those caused
of motion
◦ Those caused
◦ Those caused
by weakness
by abnormal joint position or range
by muscle contracture
by pain
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On heel strike, foot quickly
drops into plantar flexion,
producing a slapping sound
as forefoot impacts ground
Impairment
◦ Weakness of dorsiflexors
◦ May follow injury to common
peroneal nerve or hemiplegia
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Reason for deviation
◦ Inadequate strength in dorsiflexor muscles to
slowly control plantar flexion following heel contact
◦ http://www.youtube.com/watch?v=g8FIM4hQtfU
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Individual appears to be
stepping over an imaginary
obstacle; initial foot contact is
typically made with forefoot
or entire plantar surface of
foot
Impairment
◦ Marked weakness of
dorsiflexors—resulting in “foot
drop”
◦ Possibly following injury to
common peroneal nerve or
hemiplegia
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Reason for deviation
◦ In order to clear foot from ground, hip and knee must be
excessively flexed to advance leg
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http://www.youtube.com/watch?v=JLxKFL4CiAo
http://www.youtube.com/watch?v=ny0b_Audmak
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Swing leg is advanced in semicircle arc
Impairment
◦ Inability to “shorten” swing leg,
possibly due to reduced active or
passive hip or knee flexion or as a
result of wearing a “straight-leg”
brace at knee
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Reason for deviation
◦ Circumduction creates extra clearance to advance
functionally “long leg”
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http://www.youtube.com/watch?v=mxyC-26RN60
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Excessive elevation of
pelvis on “swing” side
Impairment
◦ Inability to functionally
“shorten” swing-leg
◦ Possibly due to weak hip
flexor muscles
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Reason for deviation
◦ Elevating or “hiking” pelvis provides extra clearance
for advancing leg
◦ http://www.youtube.com/watch?v=mxyC-26RN60
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Backward lean of trunk
during foot-flat phase
Impairment
◦ Weakness of hip extensors—
gluteus maximus
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Reason for deviation
◦ Leaning backward during
stance phase shifts body’s
line of gravity posterior to
hip, reducing need for active
hip extension torque
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Flexed position of hip and
knee during stance phase of
gait, often referred to as a
“crouched gait”
Impairment
◦ Hip or knee flexion contracture
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Reason for deviation
◦ Increased tightness in tissues
that allow hip and knee
extension
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During single-limb support, pelvis and trunk lean
excessively to opposite (uncompensated) or same
(compensated) side as weak hip abductor muscles
Impairment
◦ Weakness of hip abductor muscles
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Reason for deviation
◦ “Uncompensated” response: hip abductors of stance leg are
unable to produce enough force to hold pelvis level
◦ “Compensated” response: purposely leaning trunk and
pelvis to same side as weak muscles shifts line of gravity
closer to stance hip
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Trendelenburg Gait
◦ This type of gait is due to weakness of the hip
abductors (gluteus medius and minimus)
◦ The normal stabilizing affect of these muscles is
lost and the patient demonstrates an excessive
lateral list in which the trunk is thrust laterally in
an attempt to keep the center of gravity over the
stance leg
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http://www.youtube.com/watch?v=b5rIEx9Ss
Co
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Individual rises up on toes of
stance foot while swinging
contralateral leg forward
Impairment
◦ Any impairment of lower extremity
that reduces ability to functionally
reduce length of limb
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Reason for deviation
◦ Standing on tiptoes creates extra clearance for
contralateral leg to clear ground during swing
◦ http://www.youtube.com/watch?v=i2bxODibvb0
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Knee remains fully extended
throughout stance,
combined with excessive
forward lean of trunk
Impairment
◦ Weakness or avoidance of
activation of quadriceps muscle
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Reason for deviation
◦ Forward lean of trunk shifts line
of gravity anterior to mediallateral axis of knee
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Equinus Gait
◦ Equinus gait (toe-walking), one of the more
common abnormal patterns of gait of patients with
spastic diplegia, is characterized by forefoot strike
to initiate the cycle and premature plantar flexion in
early stance to midstance
◦ http://www.youtube.com/watch?v=MMM8Tqntbzo
◦ http://www.youtube.com/watch?v=eLuxTFHoZAA
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Ataxic Gait
◦ The ataxic gait is seen in two principal disorders:
cerebellar disease (cerebellar ataxic gait) and
posterior column disease (sensory ataxic gait)
◦ http://www.youtube.com/watch?v=FpiEprzObIU
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Parkinsonian Gait
◦ The parkinsonian gait is characterized by a flexed
and stooped posture with flexion of the neck,
elbows, metacarpophalangeal joints, trunk, hips,
and knees
◦ The patient has difficulty initiating movements
and walks with short steps with the feet barely
clearing the ground. This results in a shuffling
type of gait with rapid steps
◦ http://www.youtube.com/watch?v=j86omOwx0H
k
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Excessive hyperextension
of knee during stance
phase of gait
Impairment
◦ A: Quadriceps and/or knee
flexor paralysis
◦ B: Plantar flexion
contracture
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A: Overstretched posterior capsule of knee and/or
paralysis of muscles that cross posterior side of
knee (hamstrings) fail to limit knee extension
B: Leg deviates posteriorly relative to ankle and
forces knee into hyperextension, eventually
overstretching posterior capsule
http://www.youtube.com/watch?v=MUkCGd6sg1M
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Propulsive Gait - a stooped, rigid posture
with the head and neck bent forward
Scissors Gait - legs flexed slightly at the hips
and knees, giving the appearance of
crouching, with the knees and thighs hitting
or crossing in a scissors-like movement
◦ http://www.youtube.com/watch?v=UDgxjRyPe2w
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Pain (Antalgic) Gait Pattern
◦ Pain promotes a modification of the gait pattern to
avoid joint motions, muscle contraction and weight
bearing that sustains or increase the pain
◦ The resulting pattern is termed antalgic gait pattern
 Changes in gait symmetry – timing and movement
 Patient should not ambulate “through the pain”
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Increases guarding
Promotes abnormal movement patterns
Produces abnormal forces through joint structures
Uses much more energy
Irritates, inflames and can damage painful involved areas