BASIC SCIENCE
The gait cycle and its
variations with disease
and injury
The normal gait cycle
The gait cycle is comprised of the stance phase and the swing
phase. Under normal walking conditions approximately 60% of
the time is spent in stance phase and 40% spent in the swing
phase. There are also two points in the walking gait cycle e at
the beginning and end of the stance phase e where both feet are
in contact with the ground. These are termed ’double support
periods’ and account for approximately 10% of one gait cycle.
During running these double limb support periods are replaced
by periods of ‘float’ where no limbs are in contact with the
ground.
The stance phase during walking consists of five individual
sub-phases and the swing phase of three sub-phases (Figure 1)
which are now discussed further.1
Kanishk Shah
Matthew Solan
Edward Dawe
Abstract
Assessment of gait forms an integral part of the clinical examination of
the lower limbs. Normal gait requires stability and adequate clearance
and positioning of the limb throughout the gait cycle. Gait disturbances arise secondary to either musculoskeletal disorders or neuromuscular disorders. Disease processes and injuries cause
characteristic changes in gait that are clinically observed dependent
on the affected area (i.e. hip, knee, foot or ankle), aetiology and any
resulting deformities. In this article we review the normal gait cycle
and how it varies with certain disease processes and injuries.
Stance phase
Initial contact is the first of the five sub-phases of stance phase
and begins as soon as the leading foot strikes the ground. Under
normal physiological conditions the heel is the first part of the
foot to make contact with the ground, with the ankle in a dorsiflexed position. At this point during walking the other foot is
also still in contact with the ground. Initial contact is therefore
also the start of the first period of double support.
Keywords basic science; cerebral palsy; gait cycle; limb length
discrepancy
Loading response: the loading response phase follows initial
contact and begins as soon as the whole foot comes into contact
with the ground through controlled ankle plantar flexion. This
results from eccentric tibialis anterior contraction (muscle
contraction whilst the muscle-tendon unit is lengthening). Passive knee flexion occurs simultaneously, effectively making the
whole lower limb act like a shock absorber. As forward propulsion occurs the contralateral foot eventually leaves the ground,
which signals the end of the loading phase; in doing so it also
signals the end of the first double support period.
Introduction
The normal human pattern of gait is defined as a series of
movements which form a coherent and energy-efficient motion
which results in stable forward propulsion of the body. Gait occurs in different patterns, which are dependent on factors such as
the speed of the locomotion which is required (walking or
running).
The normal gait cycle consists of two distinct phases (stance
and swing) which, for the purposes of analysis, have been
broken down into sub-phases. A single gait-cycle begins at the
point at which the foot first touches the ground. When the same
foot makes contact with the ground again a full cycle of gait is
achieved. Trauma or disease processes can lead to changes in
each of the sub-phases, leading to characteristic and distinct
changes in the pattern of gait.
An understanding of the gait cycle therefore forms an
important part of the assessment of the lower limbs and can often
give clues toward disease processes as the patient enters the
consultation room.
Mid-stance: as loading response and double support ends,
mid-stance begins. The body moves forward secondary to body
weight momentum. The foot remains flat to the floor and the
ankle passively dorsiflexes. At this point the knee is locked in
extension. This requires minimal muscular effort since the
ground reaction force is anterior to the knee. Further forward
motion results in hip extension, again with minimal effort, as the
leg prepares for terminal stance (See The three rockers of gait
below, and Figure 2.).
Terminal stance: as the heel begins to lift off the floor, so begins terminal stance. During this phase loading of the foot
moves distally towards the metatarsal heads. As the knee is
fully extended the gastrocnemius muscle is at peak tension and
able to generate a powerful ankle plantar flexion force for
propulsion.
Kanishk Shah BMSc (Hons) MRCS (Ed) Orthoapaedic Registrar, Royal
Surrey County Hospital, Guildford, UK. Conflicts of interest: none
declared.
Matthew Solan FRCS (Tr&Orth) Consultant Foot and Ankle Surgeon,
Royal Surrey County Hospital, Guildford, UK. Conflicts of interest:
none declared.
Pre-swing follows terminal stance and is the point where the
limb begins to leave the ground, or ‘toe-off’. The ipsilateral hip
flexes which in turn flexes the knee allowing the foot to clear the
ground in preparation for swing phase. Clearance of the foot is
further facilitated through ankle dorsiflexion via concentric
Edward Dawe BSc (Hons) FRCS (Tr&Orth) Dip (Sports Med) Consultant Foot
and Ankle Surgeon, St Richard’s Hospital, Chichester, UK. Conflicts
of interest: none declared.
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10.1016/j.mporth.2020.03.009
BASIC SCIENCE
Figure 1 Schematic representation of gait under normal circumstances. Stance is subdivided into: initial contact, loading response, mid-stance,
and pre-swing. Swing is subdivided into: initial swing, mid-swing and terminal-swing. One completed ‘gait cycle’ is referred to as a ‘stride’. The two
periods of double support are also illustrated which occur during initial contact, the loading response and pre-swing. Reproduced from reference
13.
tibialis anterior contraction (concentric contraction e muscle
contraction whilst the muscleetendon unit shortens).
the ground reaction force of bodyweight that is exerted on the
foot (and limb). The heel effectively acts like fulcrum around
which the foot ’rotates’ with respect to forward movement or
rolling into plantar flexion. The centre of rotation of the knee
during this stage also sits anterior to the ground reaction force
arising from bodyweight. There is therefore a plantar flexion
moment exerted across the ankle and a flexion moment exerted
across the knee. The plantar flexion moment at the ankle is
controlled through eccentric contraction of tibialis anterior and
the toe extensors and the flexion moment across the knee
through eccentric contraction of the quadriceps as the cycle
progresses towards mid-stance. The ground reaction force at this
stage passes through the centre of rotation of the hip joint
therefore the hip is essential rotationally neutral during this
stage.
As the heel strikes the ground, it is passively pushed into
valgus which unlocks the Chopart joint. This allows the foot to be
flexible and so 1) accommodate uneven surfaces and 2) absorb
the shock of landing. This means the centre of gravity of the body
does not have to rise, which optimizes energy efficiency.
Swing phase
Initial, mid- and terminal swing: the swing phase of gait is
divided into three sub-phases: initial swing, mid-swing and terminal swing. As the name would imply, the limb ‘swings’ though
this phase and movement is driven primarily under momentum
generated during the stance phase. During swing phase, there
must be adequate flexion of both the hip and the knee. This is
achieved through concentric contraction of the hip flexors in
conjunction with knee flexors (hamstrings) and a small contribution from the gastrocesoleus complex. The result is flexion of
the hip and knee during the initial and the mid-swing sub-phases.
Adequate dorsiflexion of the ankle is also required in terminal
swing to achieve foot clearance from the ground. This is achieved
through concentric contraction of tibialis anterior.
The three rockers of gait
The gait cycle can also be considered in terms of three functional
rocker units, as described by Perry.1 Each rocker has a different
fulcrum and the rockers are another way of considering the
sub-phases of stance (Figure 2).
Mid-stance e the second rocker: next, the limb moves over the
foot and the ankle undergoes passive dorsiflexion. Consequently,
the vector of the ground reaction force across the lower limb
changes and now passes directly through the ankle joint. The
ankle is now acting as the fulcrum. The centre of rotation of the
Initial contact and loading response e the first rocker: during
the first rocker the centre of rotation of the ankle sits anterior to
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BASIC SCIENCE
a Gait rockers and the ground reaction force
Second
First
Third
b The three ankle rockers
Eccentric (lengthening)
contraction of anterior
compartment muscles
Eccentric (lengthening)
First
Second
Concentric (shortening)
Third
Figure 2 (a) Shows where the ground reaction force passes in each rocker with respect the centre of rotation of each of the joints. Dependent on
the joint and where the joint reaction force passes, a flexion or extension moment is created. If the ground reaction force passes through the centre
of rotation, a moment about the joint is not created. (b) Shows the three rockers but with respect to the foot and the relevant muscle contractions in
each of the rockers. Adapted from reference 14.
band of connective tissue that originates at the medial calcaneal
tubercle and spans out to insert onto the base of the proximal
phalanges of the toes. Within the foot this effectively creates a
’truss’ like structure between the calcaneum and the metatarsal
heads (Figure 3).
Extension of the big toe results in the plantar fascia being
pulled distally. This shortens distance between the calcaneum
and the metatarsal heads, shortening the truss, with rotation
occurring about the talonavicular joint. This results in raising of
the medial longitudinal arch. The origin and insertion of the
plantar facia forms the windlass mechanism around the metatarsophalangeal joints (MTPJs). This is the basis of the Jack test,
by which the medial longitudinal arch is recreated by dorsiflexion of the hallux.
When the heel is in valgus (first rocker), the axes of the
talonavicular and calcaneocuboid joints (Chopart joint) are parallel and the foot is supple and flexible, allowing it to adapt to
uneven surfaces. As the MTPJs dorsiflex and the plantar fascia is
tensioned recreating the medial longitudinal arch, the axes of
these two joints diverge. This ‘locks’ the Chopart joint and the
foot becomes a rigid structure.
It is this transient rigidity that allows rotation of the foot and
ankle to occur around the metatarsal heads. This in turn results
in the ability to ‘toe-off’ and continue moving through gait
cycle.
knee and hip passes posterior to the ground reaction force and
therefore there are extension moments exerted across both of
these joints. The knee and hip are both maintained in extension
with minimal contribution from the musculature which further
serves to conserve energy. Forward movement of the ankle (i.e.
dorsiflexion) is controlled through eccentric contraction of the
gastrocnemiusesoleus complex.
Terminal stance e the third and final rocker: as forward momentum continues, passive dorsiflexion of the ankle progresses
until the limit of the joint is reached. At that point, concentric
contraction of the gastrocnemiusesoleus complex occurs and
causes the heel to raise off the floor. The fulcrum point now
moves to the metatarsal heads. As the hip remains extended and
the ankle begins to plantarflex, the centre of rotation of the ankle
joint passes posteriorly to the ground reaction force and anteriorly to the centre of rotation of the knee, resulting in knee
flexion. Tibialis posterior contracts concentrically and induces
heel varus. This has the effect of locking the mid-tarsal joints and
transforms the foot from a flexible structure into a rigid lever
which can propel the body forward.
The plantar fascia and the windlass mechanism
The final rocker relies upon the plantar fascia and the effect that
extension of the big toe has upon it. The plantar fascia is a thick
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BASIC SCIENCE
Antalgic gait
An antalgic pattern of gait is a compensatory mechanism to
reduce pain. The pain may be arising from anywhere within the
affected lower limb. Common to all forms of antalgic gait is the
reduced amount of time spent in single stance on the affected
side e the goal being to minimize the time the affected limb is
under load. Consequently, the amount of time spent in double
support increases and swing phase of the unaffected contralateral leg is also reduced. The type of antalgic gait that is
observed will differ dependent on which part of the lower limb is
affected; therefore, it is possible to determine the cause of antalgic gait through careful observation.
The hip and gait disorders
Pathologies that can lead to hip pain include labral tears, infection, osteonecrosis of the femoral head and osteoarthritis.
Degenerative changes within the hip initially result in pain,
reduced range of movement and pain on internal rotation of the
hip.
Under physiological conditions, the centre of gravity during
the single support period of stance is in the middle of the body.
Moments are exerted across the hip joint from the weight of the
body and from the force of the abductors, which creates a
resultant joint reaction force (Figure 4).
Patients with osteoarthritis of the hip exhibit significantly
decreased walking velocity, a significantly increased double
support time and a significantly reduced stride length as well as
reduced internal rotation.2
A patient with a painful hip will be ‘looking for ways’ to
reduce the joint reaction force. There are two classical ways in
which a patient achieves this. One way is to use a walking stick
in the contralateral hand. In doing so the force required from the
abductors to stabilize the hip is reduced.
Figure 3 A truss model of the foot showing how the insertion of the
plantar fascia and extension of the big toe results in raising of the
medial longitudinal arch. This locks the Chopart joint thus making the
foot a rigid structure. Note that the distance between the metatarsal
heads and the calcaneal tuberosity decreases as the big toe goes into
extension. Adapted from reference 14.
The five pre-requisites of normal gait
Normal gait has five pre-requisites (Table 1) which were
described by Perry in 1985.
Abnormal or pathological gait occurs when one or more of
these criteria are not met. An appreciation of these principles and
the normal gait cycle allows for a detailed assessment of gait, and
how and why it might vary in pathological circumstances.
Pathological gait
Pathological gait can be thought of as secondary to either
neuromuscular disorders or musculoskeletal disorders (bone,
joints, or soft tissues).
M
My
R
Ry
A
B
Perry’s five prerequisites for normal gait
1
2
3
4
5
W
Stability in stance e a stable foot position is required
with control of the torso and arms
Adequate clearance in the swing phase e the entirety of
the limb needs to be in a position such that the foot that
is in swing will not impact or be caught by the ground
Adequate step length e This requires balance and a
stable stance side with adequate hip and knee flexion of
the swing side
Appropriate pre-positioning during swing
Energy conservation
Figure 4 Free body force diagram illustrating the forces acting across
the hip joint. W ¼ 5/6 body weight, M ¼ adductor muscle force, R ¼
joint reaction force, A ¼ Moment arm of the abductor, B ¼ Moment
arm of body weight, My ¼ Abductor moment, Ry ¼ joint reaction
moment. Adapted from https://www.orthobullets.com/recon/9064/
hip-biomechanics
Table 1
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BASIC SCIENCE
-ve
M
My
Ry
A
the affected hip. But the two can be distinguished, by careful
observation alone, because in Trendelenburg gait the contralateral pelvis will dip and the arm will not adopt an abducted
position.
R
-ve
The knee and gait disorders
During the gait cycle, knee pain results in the adoption of a
flexed position. Under normal physiological conditions, during
heel strike, a flexed knee position helps to absorb the shock of
the foot hitting the floor. It also lowers the centre of gravity
which in turn reduces energy expenditure. A painful effusion
will cause the knee to retain a flexed position throughout stance,
since flexion reduces tension across the joint capsule. Pain
within the knee maybe secondary to either degenerative or inflammatory arthritis, ligament injuries, torn menisci, infection
or a fracture.
In an antalgic gait secondary to a painful knee, heel strike is
avoided and toe walking is preferred instead, to permit the
maintenance of knee flexion.
B
W
-ve
S
Figure 5 Free body force diagram when using a stick. The reaction
force of the stick (S) acts to effectively reduce W. The weight moment
across the contralateral hip is reduced and therefore the abductor
moment is reduced which in turn reduces the joint reaction force. W ¼
5/6 body weight, M ¼ adductor muscle force, R ¼ joint reaction force,
A ¼ Moment arm of the abductor, B ¼ Moment arm of body weight,
My ¼ Abductor moment, Ry ¼ joint reaction moment. Adapted from
https://www.orthobullets.com/recon/9064/hip-biomechanics
Osteoarthritis of the knee and changes in gait: as the knee joint
becomes degenerative the range of movement deteriorates and
this affects gait. Walking speed is reduced along with stride
length. Patients attempt to compensate and minimize the impact
on the joint4
Arthritis of the knee often follows one of two patterns: varus
or valgus with the varus pattern the most prevalent.
Varus osteoarthritis of the knee can lead to a varus thrust gait.
Knee ligament injuries such as posterolateral corner injuries3 may
also lead to this pattern of gait. During the single support periods
of gait there is an exaggeration of varus deformity with return to a
less varus or more neutral position of the limb during swing.5
In patients who have a varus thrust pattern of gait there is
preferential loading of the medial compartment of the knee
which has been shown to be associated with an increased incidence of medial compartment osteoarthritis.6 Patients with a
varus pattern of osteoarthritis may potentially benefit from varus
offloading braces as a measure to reduce pain as well as slow
disease progression.
In contrast, a valgus thrust gait is observed in valgus osteoarthritis. During loading and mid stance phases of gait there is an
exaggeration of valgus deformity with return to a more neutral
position of the limb e or less valgus during the swing phase of gait.
In summary, a thrusting pattern of knee gait represents
excessive loading of the one of the tibiofemoral compartments in
relation to the other under dynamic conditions. This may be
secondary to either ligamentous laxity or injury. These patterns of
gait may arise because of conditions that pre-dispose to instability
or become apparent when the knee joint becomes arthritic.6
This in turn reduces the joint reaction force by reducing the
moment arm of the weight about the hip (Figure 5).
The other way in which a patient can reduce the joint reaction
force across the hip is to lean toward the affected hip. The centre
of gravity then moves towards the centre of rotation of the hip,
which therefore reduces the moment arm of the weight exerted
on the hip. The torso and the arm both lean over toward the
affected side to lateralize the centre of gravity. This is sometimes
referred to as lateral lurch gait and is also characterized by
abduction of the ipsilateral arm. Specific to osteoarthritis of the
hip, hip and knee flexion are reduced during the loading phase.
Internal rotation of the hip is reduced during mid-stance. In
terminal stance, there is reduced knee extension and a reduced
hip flexion moment about the hip2
This pattern of antalgic gait should not be confused with
Trendelenburg gait which is a result of abductor weakness or
dysfunction.
Trendelenburg gait
During the period of single support stance, a moment arm secondary to body weight is created about hip. If unopposed, this
would cause the pelvis to drop to the contralateral side; or toward the leg that is in the swing phase. To prevent this from
happening the hip abductors (gluteus medius and minimus)
contract concentrically on the ipsilateral side. This muscular
contraction needs to generate enough force to be able to balance
the moment arm of body weight. If the abductors are weak or
dysfunctional and cannot do this then Trendelenburg gait is
observed. As the pelvis on the contralateral side dips, the patient
moves toward the affected hip to compensate. This is referred to
as the abductor lurch. Trendelenburg gait is similar to the
lurching gait of an arthritic hip in that the torso moves towards
ORTHOPAEDICS AND TRAUMA xxx:xxx
Quadriceps avoidance gait is characterized by reduced knee
flexion throughout the stance phase of gait. There is net reduction in the knee extensor moment that is generated and hence
gait becomes less efficient. This pattern of gait is observed in
patients who have ruptured their anterior cruciate ligaments or
patients who have undergone total knee arthroplasty.
After total knee arthroplasty this pattern can persist long after
resolution of surgical pain and is associated with reduced qualityof-life scores.7
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BASIC SCIENCE
arthrodesis of the ankle.10 One assumes this occurs secondary to
other joints in the foot being ‘allowed to reach their full potential’
as the pain in the tibiotalar joint is resolved thus improving
overall sagittal plane movement. As a result of this improvement,
the time the unaffected limb spends in support reduces (i.e. the
affected limb can ‘properly go through’ terminal stance), which
in turn helps to normalize or improve stride length10
In summary both treatment options for ankle arthritis can lead
to some restoration of more normal biomechanics and gait.9,10
An arthritic ankle adversely affects gait by reducing the duration of terminal stance and reducing stride length.
Gait and limb length discrepancy
The list of causes of a limb length discrepancy includes
congenital disorders such as dysplasia of the hip, disorders of the
spine, particularly scoliosis, and degenerative conditions of the
hip such as osteoarthritis. Limb length discrepancies can also
arise as a result of surgery such as total hip replacement. Surgical
scars provide clues as to whether or not the cause is postoperative.
Limb length discrepancies can be classified as either structural
or functional. In structural causes the constituent parts of the
limb have been affected so that there has been a change in the
length of the bones. In functional discrepancies the posture of the
lower limb contributes to an apparent change in length of the
limb. One such example would be a flexion contracture of the
knee.
In a patient with a flexion contracture of the knee, the knee
cannot extend and so heel strike is compromised. This effectively
reduces stride length. In addition, the patient may toe-walk
during stance phase on the affected side.
Studies have attempted to quantify the extent of limb length
discrepancy resulting in clinically relevant sequalae. If the limb
length discrepancy is within 3% there are no associated
compensatory mechanisms involved. Above 5.5% the longer
limb needs to do more mechanical work since there is greater
vertical displacement of the centre of gravity. Clinically this is
manifested by the pelvis dipping towards the shorter side during
the swing phase, and toe-walking on the shorter of the two limbs
during stance i.e. an absence of heel strike or initial contact. On
occasion this can also manifest as circumduction of the shorter
limb or hip hiking to accommodate the longer leg.8
Steppage gait and weakness of ankle dorsiflexion (drop foot
and slapping gait): steppage gait is a pattern of gait characterized by an equinus position of the ankle. There is loss of normal
heel strike and loss of normal heel to toe progression. As a result
hip and knee flexion need to be exaggerated during the swing
phase of gait so that the toes clear the ground, because there is an
effective increase in the length of the limb.3 Common causes of a
steppage gait include equinus contractures, foot drop, trauma
and immobilization of the ankle.3
Weakness of the ankle dorsiflexors may occur with stroke,
nerve injury (commonly after pelvic or spinal trauma/surgery) or
neurological conditions such as hereditary sensory motor neuropathy (CharcoteMarieeTooth disease). There is loss of eccentric contraction of these muscles and therefore loss of control of
plantar flexion during the first rocker of gait which can result in a
‘foot slap’. If this weakness is extreme or there is complete paralysis of the anterior compartment, then the foot adopts a plantarflexed position earlier than normal i.e. in the swing phase
resulting in ’foot drop’. One compensatory mechanism for the toes
to clear the ground is for the limb to adopt steppage gait as
described above. Other patients may circumduct the longer limb
to accommodate the extra functional length. The young and
flexible may, over time, develop pelvic obliquity to compensate.
Foot and ankle and gait disturbance
Painful conditions of the foot and ankle result in an antalgic
pattern of gait dependant on which part is involved. Aetiologies
include osteoarthritis, inflammatory arthritis, trauma and infection. As a result of pain the foot will contact the ground abnormally and patients may preferentially choose to bear weight on
the heel, the forefoot or along the lateral border of the foot during
the stance phase as a result of protective supination.
The gastrocesoleus complex and its effect on gait/foot
biomechanics: if there is weakness of the gastrocesoleus complex, there will be loss of ankle plantarflexion and loss of control
of ankle dorsiflexion. As a result, there is no power in the lever
that normally ‘pushes the foot off the floor’. Toe-off is effectively
inhibited, which limits forward propulsion. The stride length on
the unaffected side is shortened to compensate. Common conditions such as rupture of the Achilles tendon, radiculopathy or
peripheral neuropathy, can result in this pattern of gait.
Conversely, tightness of the gastrocesoleus complex can also
lead to alterations in biomechanics of the foot and ankle, and
subtle alterations in the gait cycle.
If there is tightness of the gastrocesoleus complex the ankle is
unable to ‘fully unwind’ and it becomes harder to achieve full
dorsiflexion of the ankle. This affects the second and third
rockers of gait where the gastroc muscle is at maximum tension
because of knee extension. Toe-off has to begin earlier and this
overloads the fulcrum of the third rocker (the metatarsal heads).
The plantar aspect of the forefoot will display characteristic cal€ld’s test is likely
losities when examined. In addition, Silfverskio
to be positive since isolated gastrocnemius tightness is more
common than contracture of both the gastrocnemius and the
soleus.
Osteoarthritis of the ankle: patients who have painful arthritic
ankles spend less time in the stance phase of gait. In addition,
stride length and walking speed are also reduced and these may
be a way to reduce the load across the joint. Predictably the
biggest loss of range of movement of an arthritic ankle is in the
sagittal plane.
As stance progresses through the first and second rocker a
reduced range of movement of the tibiotalar joint shortens the
amount of time spent in terminal stance.
Common treatment modalities for end stage arthritis of the
ankle include fusion of the joint or total ankle arthroplasty. Total
ankle arthroplasty has been shown to improve gait characteristics with restoration back to normal parameters at 1-year followup.9 Therefore, in suitable patients, total ankle arthroplasty may
be a suitable treatment option to help restore normal ankle
movements and therefore gait.
One would expect the gait characteristics in a fused ankle to
be markedly worse but interestingly movement in the sagittal
plane has been shown to significantly improve following
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BASIC SCIENCE
The different patterns of gait in cerebral palsy and the overriding muscle forces. The ‘alpha’ angle foot position effectively
describes the position the foot will adopt with respect to the lower leg. The appropriate orthotic is also described15
Group
Group
Group
Group
I e true equinus
II e jump gait
III
IV
Foot position ( )
Overriding muscle forces
Orthotic required
>90
>90
¼90
¼90
Gastroc
Gastroc, hamstrings/rectus femoris
Hamstrings/rectus femoris, psoas
Hamstrings/rectus femoris, psoas
Hinged ankleefoot orthosis (AFO)
Hinged AFO
Solid AFO
Ground reaction AFO
Table 2
of the hip and the knee in early stance followed by extension
to variable degrees as the gait cycle progresses. The pelvis
again adopts a normal position or may be tilted anteriorly.
There are gait deviations at multiple joints and treatment options should be considerate towards treating underlying
spasticity. Given that all three joints are involved in this
pattern, the hip, knee and ankle plantar flexors are all affected
to a certain degree.
Both true equinus and jump gait patterns have similar orthotic
requirements because the second rocker of gait is inhibited. A
hinged ankle foot orthosis may be of benefit as it prevents
excessive plantar flexion. Consequently the ground reaction force
now passes anterior to the knee and is normalized.12
Tightness of the gastrocnemius leads to forefoot overload and
gives rise to conditions such as a metatarsalgia and Morton’s
neuroma. Patients who suffer from these conditions benefit from
rocker shoes, which will reduce forefoot pressures during the
third rocker of gait.
Hallux rigidus: degenerative changes at the first MTPJ result in
pain and loss of range of movement, particularly dorsiflexion of
the big toe. Approximately 65 of dorsiflexion is required to
achieve normal gait. Reduced dorsiflexion of the big toe restricts
forward propulsion and affects the toe-off sub-phase of gait and
third rocker.11 Patients avoid moving the big toe and during gait
this usually results in the foot adopting a position of protective
supination, with the lateral border of the foot being preferentially
loaded11 through external rotation of the hip. Toe-off now occurs
from the lesser metatarsal heads and may commonly result in
lesser metatarsal stress fractures or other causes of lateral forefoot pain such as Morton’s neuroma.11
Apparent equinus: in apparent equinus, the range of movement
is preserved at the ankle but there is excessive flexion of the hip
and the knee throughout stance with normal or an anterior tilt to
the pelvis.12
Gait disturbances in cerebral palsy
Numerous classifications for the gait patterns seen in cerebral
palsy have been described using qualitative data. Rodda et al. in
2004 described these gait abnormalities by combining pattern
recognition and kinematic data.12
They described five different patterns based on the position of
the ankle followed by the knee, the hip and the pelvis respectively.
1) True equinus
2) Jump gait
3) Apparent equinus
4) Crouch gait
5) Asymmetrical gait
The key muscle groups that were found to be affected by
spasticity or contracture were the flexors of the hip and knee and
the plantar flexors of the ankle.12
Crouch gait: with this pattern there is excessive dorsiflexion of
the ankle throughout stance, and excessive flexion of the knee
and the hip. The pelvis remains within normal limits or may
adopt a posterior pelvic tilt. Due to the position of the foot, the
calcaneum remains in contact with the floor for a prolonged
period of time.
The force of the hamstrings and the psoas dominates in both
apparent equinus and crouch gait. There is prolongation of the
second rocker and therefore a solid foot and ankle orthosis helps
pass the ground reaction force anteriorly more quickly facilitating gait progression.12
Asymmetric gait: as the name would suggest there is asymmetry between the two legs. Each leg may fall into different
categories; for instance one leg may fall into the category of
apparent equinus and the other in the category of jump gait12
(see Table 2).
True equinus: in true equinus the ankle adopts an equinus position. There is full extension of the knee and hip and the pelvis
remains within the normal range. As with other gait abnormalities where the ankle is in equinus, there is lack of heel strike and
patients may ‘toe-walk’.
Spasticity of the calves overrides the force of the hamstrings
and psoas and this is a pattern seen more in younger children.
These children are prime candidates for botulinium injections.
Older children tend to be affected by disease driven primarily by
contractures of the heel cord.12
Conclusion
The ability to walk upright is functionally important, irrespective
of age and occupation. Disease processes and pathologies can
often alter gait and significantly impact on activities of daily
living. Careful evaluation and observation of the gait cycle helps
to identify the pathologies that the patient has presented with. An
appreciation of the normal gait cycle and how certain disease
processes might affect it can help to achieve a diagnosis, often
before the patient has even volunteered their history, and can aid
with the selection of an appropriate treatment option.
A
Jump gait: in this pattern of gait, the ankle again adopts an
equinus position. There is abnormal and exaggerated flexion
ORTHOPAEDICS AND TRAUMA xxx:xxx
7
Crown Copyright Ó 2020 Published by Elsevier Ltd. All rights reserved.
Please cite this article as: Shah K et al., The gait cycle and its variations with disease and injury, Orthopaedics and Trauma, https://doi.org/
10.1016/j.mporth.2020.03.009
BASIC SCIENCE
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Crown Copyright Ó 2020 Published by Elsevier Ltd. All rights reserved.
Please cite this article as: Shah K et al., The gait cycle and its variations with disease and injury, Orthopaedics and Trauma, https://doi.org/
10.1016/j.mporth.2020.03.009