GAIT & GAIT ANALYSIS

GAIT HOD:DR.K.PRAKASAM M.S.ORTHO,D.ORTHO,DSc(HON)

PRESENTOR: Dr.THOUSEEF A MAJEED

DefinitionRhythmic, cyclic movement of the limbs in relation to the trunk resulting in forward propulsion of the body.

NORMAL GAIT REQUIRESNormal functioning of musculoskeletal system of lower limbs & spine.Good sensory feedback from propioceptive sensation from feet and the joints.Visual ,labrinthine sensory inputs & co ordination add smoothness, rhythm & elegance to the human gait.

GAIT TERMINOLOGYBase of supportStep lengthStride lengthGait cycleCadenceWalking velocityDouble limb supportSingle limb supportGround reaction force vector

BASIC GAIT TERMS Base of suppport:Distance between a persons feet while standing or during ambulation.Provides balance & stability to maintain erect posture.Normally 2-4 inches from heel to heel.

Step lengthLinear distance along the line of progression of one foot travelled during one gait cycle.Approximately 15 inches.

Stride lengthLinear distance in the plane of progression between successive point of foot to floor contact of the same foot. Normally 27 32 inches.

Gait cyclePeriod of time from one heel strike to next heel strike of the same limb

CadenceIt is measured as the number of steps / sec or per minute.Approximately 70 steps per minute

Double limb supportDuring normal gait, for a moment , two lower extremities are in simultaneous contact with the ground. During this period, both legs support the body weight.Happens between push off & toe off on same side and heel strike & foot flat on the contra lateral side.

GAIT CYCLE COMPONENTSStance phase :60% of the gait cycle.Swing phase :40% of the gait cycle.

STANCE PHASEHeel strikeFoot flatMidstance Heel off Toe off

Swing PHASEAcceleration Midswing Deceleration

Heel strike phase:

Beginning of stance phase when the heel contacts the ground.Begins with initial contact & ends with foot flat

Foot flat:

It occurs immediately following heel strikeIt is the point at which the foot fully contacts the floor.

Mid stance: It is the point at which the body passes directly over the supporting extremity.16

Heel off: The point following midstance the heel of the reference extremity leaves the ground.17

Toe off

The point following heel off when only the toe of the reference extremity is in contact with the ground.

HIP : STANCE PHASEPHASE NORMAL MOVEMEMTNORMAL MUSCLE ACTIONHeel strike to foot flat30* flexionErector spinae,gluteus maximus,hamstrings.Foot flat to midstance30*flexion-(neutral)Gluteus maximus at beginning to oppose flexion movement, then activity ceases as moment changes from flexion to extensionMidstance to heel offextensionNo activityHeel off to toe off10* hyperextension to neutralIliopsoas,adductor magnus,adductor longus

KNEE : STANCE PHASEPHASE NORMAL MOVEMEMTNORMAL MUSCLE ACTIONHeel strike to foot flat0*-15* flexionQuadriceps contracts initially to hold knee in extension & then eccentrically oppose the flexion movement to controll amount of flexion.Foot flat to midstance 15*flexion-5*extensionQuadriceps contract in early part,& then no activity is requiredMidstance to heel off5* of flexion-neutralNo activity required Heel off to toe off0*-40* flexionQuadriceps required to control amount of knee flexion

ANKLE & FOOT : STANCE PHASEPHASE NORMAL MOVEMENTNORMAL MUSCLE ACTIVITYHeel srike to foot flat0*-15* plantar flexionEccentric action of tibialis anterior oppose plantar flexion movementFoot flat to midstance15*plantar flexio-10*dorsi flexionGastronemius & soleus act eccentrically to oppose dorsiflexion movement & control tibial advanceMidstance to heel off 10*-15* dorsiflexion same as aboveHeel off to toe off15*dorsiflexion to 20* plantar flexionGastronemius,soleus,peroneus brevis & longus,flexor hallusis longus contract to plantar flex the foot

Swing phaseAcceleration phase:It begins once the toe leaves the ground & continues until mid-swing, or the point at which the swinging extremity is directly under the body.

Swing phaseMid-swing: It occurs approximately when the reference extremity passes directly under the body.It extends from end of acceleration to the beginning of deceleration23

Swing phaseDecelerationIt occurs after mid-swingwhen the referance extremity is decelerating in preparation for heel strike.

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HIP : SWING PHASEPHASENORMAL MOVEMENTNORMAL MUSCLE ACTIONAcceleration to mid swing20*-30* flexionHip flexor activity to initiate swing iliopsoas,rectus femoris,gracilis,sartorius,tensor fascia lataMidswing to deceleration30*flexion neutralhamstrings

KNEE :SWING PHASEPHASENORMAL MOVEMENTNORMAL MUSCLE ACTIONAcceleration to mid swing40*-60* flexionLittle activity in quadriceps,biceps femoris(short head),gracilis, sartorius contract concentricallyMidswing 60*flexion-30* extensionDeceleration 30*-0* extensionQuadriceps contract concentrically to stabilize knee in extension in preparation for heel strike

Ankle & foot : swing phasePHASENORMAL MOTIONNORMAL MUSCLE ACTIONAcceleration to midswingDorsiflexion to neutralDorsiflexors contract to bring the ankle in neutral & prevent toes from dragging on the floor Mid swing to decelerationNeutraldorsiflexion

DIFFERENCE BETWEEN WALKING AND RUNNINGWalking : Always a double support phase no flight phase

RunningNo double support phase, always flight phase

BODYPASSENGER UNITLOCOMOTOR UNITHEADARM TRUNKPELVISLOWER LIMBSHAS NO ROLE .GOES ALONG THE RIDEFUNCTIONING SYSTEMSTANCE PHASESWING PHASE

DETERMINANTS OF GAITI. Displacement of center of gravity (COG).II. Factors responsible for minimizing displacement of center of gravity.

CENTER OF GRAVITYIt is an imaginary point at which all the weight of the body is concentrated at a given instant. Center of gravity lies 2 inches in front of the second sacral vertebra.Centre of gravity follows vertical displacement and horizontal displacement

Center ofGravity

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BiomechanicsRhythmic up & down movementHighest point= midstanceLowest point=double supportAverage displacement-5 cm

Vertical displacement Horizontal displacementRhythmic side to side movementLateral limit=midstanceAverage displacement-5 cm

Hz planeVt plane

OVERALL DISPLACEMENTSum of vertical & horizontal displacementFigure 8 movement of Center of Gravity as seen from Antero Posterior These displacement require energy Greater the displacement more energy is needed.

HorizontalplaneVerticalplane

Factors responsible for minimizing the displacement of centre of gravity

Major determinants:Pelvic Rotation (transverse plane)Pelvic Lateral Tilt (Obliquity)Knee Flexion During StanceAnkle Mechanism (Dorsiflexion)Ankle Mechanism (Plantarflexion)Step Width

Minor determinants:1. Neck movement.2. Swinging of arms.

1. Pelvic rotation

Rotation of pelvis in Horizontal plane in swing phase, total of 8 degreeDecrease angle of hip flexion & extensionEnables a longer step length without further lowering of Center of gravity

2. Pelvic tilt

The pelvis slopes downwards laterally towards the leg which is in swing phase Reduces the vertical movements of the upper body, and thereby increases energy efficiency. Decrease the displacement of Center of gravity

3. Knee flexion in stance

As the hip joint passes over the foot during the support phase, there is some flexion of the knee. This reduces vertical movements at the hip.Decrease the displacement of Centre of Gravity

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4. Ankle mechanism

Lengthen the leg at heel strikeReduce the lowering of Centre of gravity, hence smoothen the curve of Center of gravity.

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5. Foot mechanism

Lengthen the leg at toe off as ankle moves from dorsiflesion to planter flexionReduce the lowering of Centre of Gravity, hence smoothen the curve of Centre of Gravity

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Trunk and Arms The trunk, arms and shoulders also rotate to ensure balanceUpper limb swings opposite to stance leg to produce a smooth balanced gait.

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6. Lateral displacement of body

In normal gait, width of walking base is narrow, decrease the lateral displacement of Centre of GravityDecrease muscular energy consumption due to decrease lateral acceleration & deceleration

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Due to complex interaction of muscular activity & joints motion in lower limb Centre of Gravity follows a smooth sinusoidal curve. It reduce the significant energy consumption of ambulation.

GAIT IN CHILDREN (