standing up

8/6/2019 Standing Up

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Standing up and sitting downStanding up and sitting down

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Standing up: description of theStanding up: description of the

actionaction PrePre--extension phase VS. extension phaseextension phase VS. extension phase

Feet backwardFeet backward

PrePre--extension phase :Upper body rotateextension phase :Upper body rotateforward at hipforward at hip thigh move forwardthigh move forward shankshank

rotate forward at anklerotate forward at ankle active ankleactive ankle

dorsiflexion (horizontal momentum: hipdorsiflexion (horizontal momentum: hipflexion and ankle dorsiflexion)flexion and ankle dorsiflexion)


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Standing up: description of theStanding up: description of the

actionaction Extension phase: vertical momentum: hip,Extension phase: vertical momentum: hip,

knee and ankle extentknee and ankle extent

horizontal momentumhorizontal momentum and verticaland verticalmomentum have some overlap: forming onemomentum have some overlap: forming one

continuous forward and upward movementcontinuous forward and upward movement


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KinematicsKinematics

The generation of horizontal linearThe generation of horizontal linear

momentum of the body mass move the bodymomentum of the body mass move the body

mass forward over the new BOSmass forward over the new BOS The translation of horizontal momentum toThe translation of horizontal momentum to

vertical momentumvertical momentum


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KinematicsKinematics

Horizontal momentum: clockwise rotation ofHorizontal momentum: clockwise rotation of

the trunk at hip and of the shank at anklethe trunk at hip and of the shank at ankle

Vertical momentum: counterVertical momentum: counter--clockwiseclockwiserotation of the trunk and shank+ clockwiserotation of the trunk and shank+ clockwise

rotation of the thighrotation of the thigh

Variation: different foot placement, initialVariation: different foot placement, initialbody positions and speedbody positions and speed


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KineticsKinetics

Major force generation : the thighMajor force generation : the thigh--offoff

A decrease in force at one joint can beA decrease in force at one joint can be

compensated for by an increase at the othercompensated for by an increase at the otherjoint to ensure the limb dose not collapsejoint to ensure the limb dose not collapse

Vertical ground reaction force: peakingVertical ground reaction force: peaking

around the thigharound the thigh--offoff


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Muscle activityMuscle activity

Tibialis anteriorTibialis anterior

First muscle to be activatedFirst muscle to be activated

its role in foot placement backwardits role in foot placement backward Stabilizing the shank on the footStabilizing the shank on the foot

Forward movement of the shank on the footForward movement of the shank on the foot

Hip extensors and knee extensorsHip extensors and knee extensors Onset simultaneouslyOnset simultaneously

Peak activity: thighPeak activity: thigh--offoff


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Muscle activityMuscle activity

Gastrocnemius and soleusGastrocnemius and soleus

Variable patternVariable pattern

Balance the body massBalance the body mass IliopsoasIliopsoas

Initiator of the trunk flexionInitiator of the trunk flexion

Rectus femoris and bicep femorisRectus femoris and bicep femoris Onset simultaneouslyOnset simultaneously

Control of hip flexionControl of hip flexion


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Factors influencing performanceFactors influencing performance

Trunk segmentTrunk segment

A high level of overall muscle force has to beA high level of overall muscle force has to beproduced over a longer period of time whenproduced over a longer period of time when

subject stood up from the fully flexed position ofsubject stood up from the fully flexed position ofthe trunkthe trunk

Starting active trunk flexion from erect positionStarting active trunk flexion from erect position

Swing trunk forward at a reasonable speedSwing trunk forward at a reasonable speed

Extension phase dose not commence with theExtension phase dose not commence with thetrunk stationary and flexed forwardtrunk stationary and flexed forward


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Factors influencing performanceFactors influencing performance

SpeedSpeed

Increased velocity of trunk flexion has aIncreased velocity of trunk flexion has a

potentiating effect on extensor force productionpotentiating effect on extensor force production Practice of a range of speed is criticalPractice of a range of speed is critical


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Sitting downSitting down

Controlled by extensor moment at the hip,Controlled by extensor moment at the hip,

knee and ankle while joint are flexionknee and ankle while joint are flexion

Lacks the facilitating effect of the trunk flexion:Lacks the facilitating effect of the trunk flexion:required considerable muscle strength andrequired considerable muscle strength and

control ,particularly at the kneecontrol ,particularly at the knee

Increased time spent in the seat contactIncreased time spent in the seat contact

phasephase

Horizontal momentum was discontinuous: SITHorizontal momentum was discontinuous: SIT

may be under more feedback controlmay be under more feedback control


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Change in the elderlyChange in the elderly

Decrease vigourDecrease vigour

use handuse hand

may not be use to reduce joint momentmay not be use to reduce joint moment Used to gain more stabilityUsed to gain more stability

Used to decrease force requirement at kneeUsed to decrease force requirement at knee

Inability to produce sufficient joint momentInability to produce sufficient joint momentmay not be a factor limiting the ability tomay not be a factor limiting the ability to

stand up in healthy elderly subjectstand up in healthy elderly subject


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Motor dysfunctionMotor dysfunction

Individual with neutral dysfunction tend toIndividual with neutral dysfunction tend to

stand up more slowlystand up more slowly

Change in spatial characteristics of action isChange in spatial characteristics of action isless than in the temporal aspects of theless than in the temporal aspects of the

actionaction

Vertical ground reaction force traces of STSVertical ground reaction force traces of STSfollowing stroke show either no discerniblefollowing stroke show either no discernible

peak or the peak occurs later in the actionpeak or the peak occurs later in the action


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Motor dysfunctionMotor dysfunction

Common observable deficitCommon observable deficit

Difficulty generating and timing sufficient forceDifficulty generating and timing sufficient force

Failure to place one or both feet backwardFailure to place one or both feet backward Failure to move the body mass sufficiently farFailure to move the body mass sufficiently far

forward at thighforward at thigh--offoff

Difficulty balancing the body massDifficulty balancing the body mass


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Adaptive motor behaviourAdaptive motor behaviour

Weakness of lower limb extensorsWeakness of lower limb extensors

Hemiplegia: Stands up by generating forceHemiplegia: Stands up by generating force

through intact leg, this foot may be positionedthrough intact leg, this foot may be positionedbehind the weaker. (fig. 4.11)behind the weaker. (fig. 4.11)

Diplegia: No moving body mass forward overDiplegia: No moving body mass forward over

feet, just flexing lumbar spine instead of flexingfeet, just flexing lumbar spine instead of flexing

hips. (fig. 4.12)hips. (fig. 4.12)


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Adaptive motor behaviourAdaptive motor behaviour

Lack of balance and stabilityLack of balance and stability

Upper body segment: Hands supportUpper body segment: Hands support

Lower body segment: Wide the base of supportLower body segment: Wide the base of support


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Essential componentEssential component

Initial foot placement backwardInitial foot placement backward

(approximately 10cm from an imaginary(approximately 10cm from an imaginary

vertical line drawn form the knee joint).vertical line drawn form the knee joint). Flexion of the erect trunk segment at theFlexion of the erect trunk segment at the

hips and dorsiflexion at the ankle.hips and dorsiflexion at the ankle.

A sequence of lower limb extension (knee,A sequence of lower limb extension (knee,hip, and ankle).hip, and ankle).


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TrainingTraining

A critical factor in the ease of STS is footA critical factor in the ease of STS is foot

placement backward (approximately 75placement backward (approximately 75

ankle dorsiflexionankle dorsiflexion).).


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TrainingTraining

Modification of the environmentModification of the environment

1. The height of the seat.1. The height of the seat.

2. The seat should not have arm.2. The seat should not have arm. 3. Flexibility.3. Flexibility.

4. Chair design.4. Chair design.


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Chair designChair design

Factors of chair design:Factors of chair design:

1. Easy to get out.1. Easy to get out.

2. Height of seat and place the feet back.2. Height of seat and place the feet back. 3. Comfort and texture.3. Comfort and texture.

Depth and slant of the seat.Depth and slant of the seat.

Increased EMG activity in the vastus lateralis.Increased EMG activity in the vastus lateralis.


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TrainingTraining

Repetition:Repetition:

1. Strengthen the muscles of this action.1. Strengthen the muscles of this action.

2. Optimize learning.2. Optimize learning. Timing & coordinationTiming & coordination


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TrainingTraining

PracticePractice

1. Strengthening exercise1. Strengthening exercise

2. Manual guidance2. Manual guidance 3. Demonstration and augmented feedback3. Demonstration and augmented feedback

4. Self4. Self--monitored practicemonitored practice


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Strengthening exerciseStrengthening exercise

Repetition of STS & SITRepetition of STS & SIT

Strength of muscleStrength of muscle

Concentric activity & eccentric activityConcentric activity & eccentric activity Control lengthening of muscles (timing)Control lengthening of muscles (timing)

Repetitive stepping exerciseRepetitive stepping exercise

I

ncrease strength in L/E extensor.I

ncrease strength in L/E extensor. Stretch calf muscles.Stretch calf muscles.


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Manual guidanceManual guidance

Passive movement:Passive movement:

positionalignment & giving a idea ofpositionalignment & giving a idea of

movement.movement.

Physical restriction:Physical restriction:

hold the shank ground reaction force tohold the shank ground reaction force to

propel the body.propel the body.

Push knee be extendedbody mass centredPush knee be extendedbody mass centred

over BOS.over BOS.


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Demonstration and augmentedDemonstration and augmented

feedbackfeedback Beside demonstration & sagittal plane viewBeside demonstration & sagittal plane view

Video feedback & auditory feedbackVideo feedback & auditory feedback


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SelfSelf--monitored practicemonitored practice

Kottke (1974)Kottke (1974)

Canning (1987)Canning (1987)

For example: fig. 4.19a, bFor example: fig. 4.19a, b


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Physical assistancePhysical assistance

Transfer V.S. get into standingTransfer V.S. get into standing


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Measurement of outcomeMeasurement of outcome

Fig. 4.20Fig. 4.20

Smooth , bellSmooth , bell--shaped velocity curve: Wellshaped velocity curve: Well--

coordinationcoordination

Fig. 4.21Fig. 4.21

Hip and knee angular velocity at MSA 2 & 6Hip and knee angular velocity at MSA 2 & 6

MAS 4.5dischargeMAS 4.5discharge

standing up

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