PowerPoint Presentation

Task Determinants of Wheelchair PropulsionKacie WashburnSamantha Jensen

970-310-6394

No matter which way I do It, what do I have to be able to do?1

Push PhaseApply a grip to the pushrim Stabilize base of support Transfer a force from the upper extremity to the pushrim

1. Apply a grip force to the pushrim

High Impact Force on the Wrist

2. Stabilize base of support

Postural Control

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3. Transfer a force from UE to pushrim

STYLESFORCE REQUIRED0.56 Newtons0.58 Newtons0.45 Newtons

Contact Angle

Minimum amount of joint mobility9

Surface Effects

HardwoodCarpetRamp0.45 Newtons0.54 Newtons0.52 Newtons

Peak Torque occurs at 30-40 degrees into the push phase

Push phase Kinematics

Early Push Phase:Late Push Phase:ROMMusclesShoulderFlexionAnterior DeltoidElbow ExtensionTricepsWristRadial DeviationExtensor Carpi Radialis

ROMMusclesShoulderFlexionAnterior Deltoid, PectoralisElbow ExtensionTricepsWristUlnar DeviationExtensor Carpi Ulnaris

Recovery PhaseRelease the grip from the pushrimReturn the upper extremity to its original position

4. Release Grip

5. Return to Original Position

Recovery Kinematics

Early Recovery Phase:Late Recovery Phase:ROMMusclesShoulderExtensionPosterior Deltoid, TricepsElbow ExtensionTricepsWristNeutralN/A

ROMMusclesShoulderExtensionPosterior Deltoid, TricepsElbow FlexionBicepsWristRadial DeviationExtensor carpi radialis

Efficiency: Work per Metabolic Energy 5-10%20-25%

Wheelchair Fit

A: angle too small C: angle is too largeB:correct angle = 100-120

Semicircular Propulsion Style

Length or distance hands are in contactMinimum angle

Normalize force by percent body mass

Transfer load from UE to rim

StabilityStability to create mobility Force from a fixed unit 19

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