Introduction to Bio Mechanics Slide Show

Biomechanics IBiomechanics I 11

What is biomechanics?What is biomechanics?

Application of Application of

mechanical mechanical principlesprinciples

in the study ofin the study of

living organismsliving organisms

Biomechanics IBiomechanics I 22

Biomechnaics = Bio + Mechanics

BioBioliving organismsliving organisms

MechanicsMechanicsthe study of the action of forces on the study of the action of forces on particles and mechanical systems; particles and mechanical systems; a branch of physicsa branch of physics

Biomechanics IBiomechanics I 33

Sub-branches of Sub-branches of biomechanicsbiomechanics

kinematics:kinematics: study of the study of the appearance or description of appearance or description of motionmotion

kinetics:kinetics: study of the actions of study of the actions of forcesforces

Biomechanics IBiomechanics I 44

Sub-branches of Sub-branches of biomechanicsbiomechanics

statics:statics: study of systems in study of systems in

constant motionconstant motion

dynamics:dynamics: study of systems study of systems

subject to accelerationsubject to acceleration

Biomechanics IBiomechanics I 77

Main Themes in Main Themes in BiomechanicsBiomechanics

SafetySafety: Prevention of injury : Prevention of injury

EffectivenessEffectiveness: maximization of the : maximization of the

output output

EfficiencyEfficiency: economy of energy : economy of energy

expenditureexpenditure

Biomechanics IBiomechanics I 88

What is Biomechanics used for?What is Biomechanics used for?

Improving Sports PerformanceImproving Sports Performance

– – Better techniqueBetter technique

– – Better equipment (Better equipment (e.g. e.g. klapskates)klapskates) Sports Injury PreventionSports Injury Prevention

– – Identifying safer techniquesIdentifying safer techniques

– – Developing protective equipment Developing protective equipment

((e.g. e.g. ankle brace)ankle brace)

Biomechanics IBiomechanics I 99

What is Biomechanics used for?What is Biomechanics used for?

Occupational Injury Prevention Occupational Injury Prevention

– – ((e.g. e.g. low back pain, hand & wrist low back pain, hand & wrist trauma)trauma)

Injury RehabilitationInjury Rehabilitation

– – Identify when safe to return to Identify when safe to return to activityactivity Improving MobilityImproving Mobility

– – ((e.g. e.g. surgery planning in cerebral palsy)surgery planning in cerebral palsy)

Biomechanics IBiomechanics I 1010

What is Biomechanics used for?What is Biomechanics used for?

Reducing Physical or Functional DeclinesReducing Physical or Functional Declines

– – ((e.g. e.g. reducing injurious falls in olderreducing injurious falls in older

adults; preventing bone loss in olderadults; preventing bone loss in older

space)space)

• • Product DesignProduct Design

– – ((e.g. e.g. athletic shoes, prosthetics, athletic shoes, prosthetics,

artificial joints)artificial joints)

Biomechanics IBiomechanics I 1111

Study of Biomechanics’ Study of Biomechanics’ problemproblem

Biomechanics IBiomechanics I 1212

qualitative:qualitative: pertaining to pertaining to quality (without the use of quality (without the use of numbers)numbers)

quantitative:quantitative: involving involving numbersnumbersAnalysis Evaluation

/

Testing

Intervention

Performance

Biomechanics IBiomechanics I 1313

Directional TermsDirectional Terms

Anterior / posterior:Anterior / posterior: toward the toward the

front/back of the body front/back of the body

= ventral/dorsal= ventral/dorsal

Medial / lateral:Medial / lateral: toward/away toward/away

from the midline of the bodyfrom the midline of the body

Biomechanics IBiomechanics I 1414

Superior / inferior:Superior / inferior: closer/farther closer/farther

to/from the head = cranial/caudalto/from the head = cranial/caudal

Proximal / distal:Proximal / distal: closer/away to/from closer/away to/from

the trunkthe trunk

Superficial / deep:Superficial / deep: inside the body inside the body

and toward/away from the body surfaceand toward/away from the body surface

Directional TermsDirectional Terms

Biomechanics IBiomechanics I 1515

Anatomical Reference PositionAnatomical Reference Position erect standing erect standing

positionposition feet slightly feet slightly

separatedseparated and and pointed forwardpointed forward

arms hanging arms hanging relaxed at the sidesrelaxed at the sides

palms of hands palms of hands facing forwardfacing forward

Biomechanics IBiomechanics I 1616

Plane of MotionPlane of Motion

Plane: the imaginary flat surfaces Plane: the imaginary flat surfaces

that pass through the bodythat pass through the body

– Sagittal : side viewSagittal : side view

– Coronal (Frontal) : front and Coronal (Frontal) : front and

back viewback view

– Transverse (Horizontal) : top Transverse (Horizontal) : top

and bottom viewand bottom view

Biomechanics IBiomechanics I 1717

Biomechanics IBiomechanics I 1818

Axis of MotionAxis of Motion

• Axis : the imaginary or real line Axis : the imaginary or real line

around which movement takes around which movement takes

placeplace

– perpendicular to the plane of perpendicular to the plane of

movementmovement

– Medial-LateralMedial-Lateral

– Anterior-Posterior Anterior-Posterior

– Longitudinal Longitudinal

Biomechanics IBiomechanics I 1919

Planes and Axes of Planes and Axes of MotionMotion

PlanePlane AxisAxis MovementMovement

SagittalSagittal Medial-Medial-Lateral Lateral

Flexion / Extension

Dorsiflexion / Plantar Dorsiflexion / Plantar FlexionFlexion

Anterior / Posterior Pelvic Anterior / Posterior Pelvic TiltTilt

Frontal Frontal (Coronal)(Coronal)

Anterior-Anterior-PosteriorPosterior

Abduction / / Adduction

Lateral Flexion / Lateral Lateral Flexion / Lateral TiltTiltInversion / / Eversion

TransverseTransverse LongitudinalLongitudinal Internal / External Internal / External RotationRotationPronation / / Supination

Horizontal Abduction / Horizontal Abduction / AdductionAdduction

Biomechanics IBiomechanics I 2020

Movements can be defined Movements can be defined based on how they relate to the based on how they relate to the bodybody

Flexion / ExtensionFlexion / Extension

Abduction / AdductionAbduction / Adduction

Internal rotation / External Internal rotation / External rotationrotation

Plantarflexion / DorsiflexionPlantarflexion / Dorsiflexion

Biomechanics IBiomechanics I 2121

Biomechanics IBiomechanics I 2222

Motion of ObjectsMotion of Objects Linear motion (Translation):Linear motion (Translation): motion motion

in which a straight line drawn between 2 in which a straight line drawn between 2

or more points on the body maintain the or more points on the body maintain the

same direction during the movement same direction during the movement

(show the same trajectory (motion along (show the same trajectory (motion along

a line))a line))

All points along the line will move All points along the line will move

along the parallel pathsalong the parallel paths

Biomechanics IBiomechanics I 2323

Straight paths rectilinear Straight paths rectilinear motionmotion

Biomechanics IBiomechanics I 2424

Biomechanics IBiomechanics I 2525

Curved paths curvilinear motionCurved paths curvilinear motion

Biomechanics IBiomechanics I 2626

Biomechanics IBiomechanics I 2727

Angular motion (Rotation):Angular motion (Rotation): rotation rotation around a fixed axis has all points around a fixed axis has all points

on a rigid segment moving in on a rigid segment moving in parallel planes along circular paths parallel planes along circular paths

about the axisabout the axis

Biomechanics IBiomechanics I 2828

Biomechanics IBiomechanics I 2929

General MotionGeneral Motion - combination - combination of linear motion + angular of linear motion + angular

motionmotion

Biomechanics IBiomechanics I 3030

Biomechanics IBiomechanics I 3131

Motion of rigid bodyMotion of rigid body

All motions can be decomposed into All motions can be decomposed into the three translations and three the three translations and three rotationsrotations

For a motion to be categorized, the For a motion to be categorized, the following must be defined:following must be defined: Type of motion (linear or angular)Type of motion (linear or angular) The reference frameThe reference frame Degree of freedom (2D or 3D)Degree of freedom (2D or 3D)

Biomechanics IBiomechanics I 3232

2-D Reference Frame2-D Reference Frame

Biomechanics IBiomechanics I 3333

3-D Reference Frame3-D Reference Frame

Biomechanics IBiomechanics I 3434

Degrees of FreedomDegrees of Freedom

Biomechanics IBiomechanics I 3535

LeverageLeverageF R

First class

R F

Second class

F R

Third class