GAIT CYCYLE
Gait cycle is the cyclic pattern of movement that occurs while
walking.
A single gait cycle begins when the heel of one foot strikes the
ground and ends when the same heel touches the ground
again.
Healthy functioning of several body systems are involved in
walking. These systems includes: musculoskeletal, nervous,
cardiovascular and respiratory.
These systems provide balance, mobility, stability and higher
cognitive function and executive control.
Loss of gait function can result to falls, injuries, loss of
movement, personal freedom and reduced quality of life.
GAIT
This is the action of locomotion.
It is a complex whole body movement that requires the
coordinated action of many joints and muscles.
It mostly involves the lower limbs, upper limbs, pelvis and
spine.
PHASES OF GAIT
The two main phases of gait are:
Stance phase
Swing phase
These phases also have subphases.
Stance phase
This is the period of the gait cycle when the foot is on the
ground and carrying the weight of the body.
This phase consists of five subphases;
The heel strike (initial response). This is when the heel of the
foot makes initial contact with the ground.
It requires the body’s weight to be accepted by the leg making
contact with the ground.
The foot flat (loading response) second phase. The foot rolls
forward until the entire plantar surface is in contact with the
ground.
The midstance (third phase). This begins when the weight of
the body is propelled forward, directly over the lower extremity
so that the greater trochanter of femur is directly above the
middle of the foot.
At this stage the whole body weight is being balanced over
one leg.
The heel-off (fourth phase). This involves lifting the heel off
the ground.
The body weight is now shifted to the contralateral leg.
The toe-off (fifth phase). This includes pushing the toe into
the ground while the ankle plantarflexes, creating forward
propulsion.
SWING PHASE.
This is another phase of gait when the foot is free to move
forward. It the period of toe-off and heel strike.
This consists of three subphases:
The early swing (acceleration phase) is the first subphase
during which the foot is lifted from the ground.
There is dorsiflexion at the ankle and flexion of the knee so
that the foot and toes can be moved from the ground.
The hip flexes to bring the leg forward moving it directly under
the body.
The mid-swing phase is the next phase in which the nonweight bearing leg passes directly beneath the body and past
the weight bearing leg.
The trunk is moved forward simultaneously so that the weight
of the body is directly over the weight bearing leg.
Dorsiflexion of foot
The late swing (deceleration phase) is the last subphase.
The foot is moved to a position in front of the body, the knee
extends and momentum decelerates.
The lower limb gets ready for heel strike and prepares to
accept the transfer of body weight for the start the next stance
phase.
As the leg moves, the rest of the body does same also.
The pelvis rotates forward along with the swing leg
At the same time the thorax and spine rotate in the opposite
direction to maintain balance.
The contralateral arm assists balance and propulsion by
swinging forward at the same time as the opposite leg.
JOINT MOTION AND MUSCLE ACTIVITY DURING GAIT
Muscles may contract : Concentrically (shorten, creating
movement and acceleration).
Eccentrically (controlled muscle lengthening, causing
deceleration.
Isometrically (muscle contracts without shortening or
lengthening creating stability).
Hip joint
The hip flexes during the swing phase and extends during the
stance phase of gait.
Flexion of the hip is performed by flexor muscles of the hip to
produce the forward swing movement of the lower extremity.
Action is performed mainly by iliopsoas muscle. Movement is
facilitated by the eccentric contraction of the hamstring
muscles (biceps femoris, semimembranosus,semitendinosus).
Hip extensor muscles (gluteus maximus and hamstring
muscles) act to stabilize the pelvis during shock absorption.
Control the forward momentum of the body as the weight is
shifted forward over the stance leg.
Hip abductor muscles (gluteus medius and minimus) act to
stabilize the pelvis, preventing pelvic dropping on the side of
the free leg.
Hip adductor muscles (adductor longus, brevis, adductor
fibres of A. magnus, pectineus ,gracilis) control the balance in
the weight bearing leg.
KNEE JOINT
The knee is held in stable extended position as the foot makes
contact with the ground during heel strike by;
Concentric contraction of the quadriceps femoris muscles
Eccentric contraction of the hamstring muscles.
The knee remains extended throughout the stance phase to
allow for stable weight bearing by lower limb.
As the lower limb absorbs shock in contact with ground, the
knee exhibits a small flexion wave movement.
During the swing phase the knee move from extension into flexion,
then back to extension.
This is due to the action of the knee flexor and extensor muscles to
ensure controlled acceleration and deceleration of the leg.
FOOT AND ANKLE
Dorsiflexion of the ankle occurs when the foot swings through to
make contact with the ground at heel strike.
Plantarflexion then occurs immediately by eccentric contraction of
the ankle dorsiflexor muscles (tibialis anterior, ext digitorum longus,
ext halluces longus, fibularis tertius) as the foot rolls forward into
foot flat position.
Forceful plantarflexion occurs by the actionof gastrocnemius and
soleus muscles creating propulsion during heel-off and toe-off
stages.
GAIT PATTERN
This is defined as the gait characteristics of an individual.
It is dependent on a number of individual variables such as; age,
height, weight, sex, walking speed, strength, flexibility and aerobic
conditioning.
Gait alterations can be caused by: different deformities, injuries,
weakness, disease or pain in any part of the body.e.g loss of
dorsiflexion could be as a result of L5 nerve root compression,
peroneal nerve compression, stroke or neurological condition
(multiple sclerosis).
GAIT DISORDERS
This results in altered distance and time variables.
Decreased speed and stride length may indicate bilateral limb
involvement,
Abnormal swing-stance ratios could suggest problems in a
single limb.
Age, fatigue, pain, musculoskeletal injury and certain
neurological disorders can all decrease step and stride lengths.
Antalgic gait
An antalgic or painful gait occurs as a result of injury to the
lower extremity.
The altered gait pattern include the shorter stance phase for
injured limb and the shorter swing phase for uninjured limb.
There is decreased walking velocity. This condition is also
known as limping.
Arthrogenic gait
This occurs as a result of abnormal joint motion which may or
not be associated with pain. E.g knee stiffness
Ataxic gait
This occurs as a result of cerebellar dysfunction.
Features include wide step width and jerky, irregular,
uncoordinated movements. The person may stagger.
Hemiplegic gait
This is described as unilateral weakness on the affected side
with weakness in flexion and dorsiflexion.
The person swings the paraplegic leg outwards and in a
circular motion in order to bring the leg forward.
The affected upper limb is flexed, adducted, internally rotated
and placed against or across the trunk as a way of improving
balance e.g in stroke patients.
Parkinsonian gait
This is characterised by flexion rigidity of the major joints such as
hip, shoulder and knee.
There is also bradykinesia (short rapid steps).
Trendelenburg gait/sign
This sign is when while standing on one leg, the free side of the
pelvis drops towards the floor.
It is caused by weakness of the gluteus medius and minimus muscle
of the contralateral stance leg.
When during walking there is excessive hip swing or wobbling, it is
known as Trendelenburg gait.
Foot drop (steppage) gait
This is a neuropathic gait where weak or paralysed dorsiflexor
muscles prevent the talocural joint in the early swing phase.
The toes may point towards the ground during walking. To
counter this gait, the person compensates with increased knee
flexion and a high step in order to clear the foot from the
ground.
Foot drop gait may be as a result of amyotrophic lateral
sclerosis, lower motor neuron lesions, cauda equina, L5 nerve
root compression or peripheral neuropathies.
Equinus (toe walking) gait
This is observed in children with clubfoot deformity (equinovarus).
Weight bearing is mainly performed by the dorsolateral edge of the
foot.
Short leg gait
In this situation the asymmetry in leg lengths will lead to a lateral
shift towards the shortened side, with pelvic tilting leading to
limping.
It is caused by scoliosis, contractures and deformity of one or more
of the leg bones.
End of lecture
References
Roberto Gruiicic (2023). Gait cycle. Kenhub.com.
Levangie P.K, Norkin C.C (2005). Joint structure and function: A
comprehensive analysis (5th ed.) Philadelphia, PA: F.A. Davis Co.
Magee David J (2002). Orthopedic physical assessment.(6th ed.)
Philadelphia: saunders.
Muscolino J.E (2011). Kinesiology. The skeletal system and muscle
function 3rd ed.)st Louis, Mo: Mosby/Elsevier.
Oatis C (2009). Kinesiology the mechanics and pathomechanics of
human movement. (2nd ed.) Baltimore: Lippincott Williams and
Wilkins.