La Gait Analysis grandezze dinamiche e casi clinici.

Manuela Galli, DEIB, POLITECNICO DI MILANO

Programma

3. La valutazione del cammino – Gait analysis

3.1. Obiettivi della valutazione quantitativa del cammino in ambito clinico.

3.2. Protocolli e standard internazionali.

3.3 Introduzione alla valutazione del report di prove di gait analysis : parametri spazio temporali e grafici di cinematica articolare.

3.4 Prova pratica di Gait Analysis

3.5 Valutazione dei tracciati di dinamica articolare e di eletromiografiasuperficiale

4. – Applicazioni cliniche dell’analisi del movimento in ambito clinico

4.1. La Gait Analysis nel bambino con PCI

4.2. Analisi del movimento nel paziente con Malattia di Parkinson

4.3 Analisi del movimento nel paziente con Sclerosi Multipla.

Motion analysis lab

Optoelectronicsystem-kinematics

Platform -kinetic

EMG –muscularactivity

Video cam –video analysis

Argomenti trattati

I parametri di output della Gait Analysis• I parametri spazio temporali• La cinematica articolare • La dinamica articolare e l’EMG

Kinematics

X,Y,Z

Trajectories

Velocities

Accelerations

Angles,…

Kinematic

Argomenti trattati

I parametri di output della Gait Analysis• I parametri spazio temporali• La cinematica articolare • La dinamica articolare e l’EMG

-

Kinetics evaluation : the ground reactions forces

P

KINETICS DESCRIBE THE CAUSES OF THE MOVEMENT

� Ground Reaction Forces Measured

GROUND REACTION FORCES and COP

Ant/posterior Medial/lateral

Vertical CoP

� Ground Reaction Forces

� Gravitational forces

Ff=mfg

Fs=msg

Ft=mtg

Foot

Shank

Thigh -bone

� Ground Reaction Forces

� Gravitational forces

� Inertial forces Fi= -ma

Ffi=- mfa

Fsi=- msa

Fti=-mta

Foot

Shank

Thigh -bone

� Ground Reaction Forces

� Gravitational forces

� Inertial forces

Measured

and computed

Biomech modelForces Joint Moment

MOMENT OF FORCE

A force acting at a distance from the rotational center causing the body to rotate

M = F x D

MOMENT

= F b

Fexb

Mex

Courtesy of the National Institutes of Health - USA

Mex= M int

Mint

M int= ligament and muscles

actions

Forces and moment

INTERNALF e M produced by muscles, ligaments and soft tissues

EXTERNALF e M produced by ground reaction forces, by segments weight and inertial forces

Plan

Dorsi

THE BODY PRODUCES >>>> INTERNAL MOMENTSIN RESPONSE TO >>>>>>>>>EXTERNAL LOADSTHAT PRODUCE>>>>>>>EXTERNAL MOMENTS

EQUILIBRIUM ���� Internal Moments = External Moments

POWER

= M

Mαααα

αααα.

Courtesy of the National Institutes of Health - USA

Power

PowerPower indicates the rate at which a moment is rotat ed

Power = Moment x Angular Velocity

Power = Force x Distance x Angular Velocity

[W]

Generated power > 0

Momentum and movement are in the same direction

Flex-extension velocity increases

Muscle concentric contraction (the contracting muscle shortens under tension)

Absorbed power < 0

Momentum and movement are not in the same direction

Flex-extension velocity decreases

Muscle eccentric contraction (the contracting muscle lengthens under tension)

GEN

ABS

Sagittal plane: knee

FIRST PART

Flexion

Extension moment

Absorbed power

Eccentric contraction

of the extensors

SECOND PART

Flexion

Flexion moment

Eccentric contraction

of the gastrocnemius

THIRD PART

Extension

Flexion moment

Absorbed power

Eccentric contraction

of the flexors

Hip joint kinetics

MOVEMENT:

FLEXION

EXTERNAL MOMENT:

EXTENSION MOMENT

INTERNAL MOMENT:

FLEXION MOMENT

FIRST PART

Extension

Extension moment

Generated power

Concentric

contraction extensors

SECOND PART

Extension

Flexion moment

Absorbed power

Silent extensors

� gravity

THIRD PART

Flexion

Flexion moment

Generated power

Concentric

contraction of the

ileopsoas (rectus

femoris)

FOURTH PART

Flexion

Extension moment

Concentric

contraction extensors

Sagittal Plane

Fi= -m*a

Clinical examples

Kinetics

of an hemiplegic child

right hemiplegia

Pdf

Clinical example - Ankle kinetics

Sagittal plane kinematics and kinetics :ankle

Sagittal plane kinematics and kinetics : knee

Sagittal plane kinematics and kinetics : hip

FX,FY,FZ,

COP

Forces

Torques

Powers

Kinetics

Kinetics

xy

Palestrina, 27 Maggio 2016

EMG

Equipment: EMG

Tibialis Anterior

Gastrocnemius

� Timing

Perry, 1992

EMG signal evaluation

Output of EMG

Reference muscle activity

EMG evaluation

EMG signals

Co-contractions

Timings

…

EMG

EMGKineticsKinematic Video

Thank you