Motion Analysis

Summer Course

Speaker: Yi-Jung Tsai

Date: 2011/07/13

Motion Analysis Laboratory

Motion Analysis Lab

Outline• Part I: Introduction of motion analysis

• Basic introduction• Research methods in motion analysis

• Instrumentation• Data collection• Data analysis

• Part II : Application• Gait analysis• Clinical application• Sports medicine

Motion Analysis Lab

• Part I: Introduction of motion analysis• Basic introduction• Research methods in motion analysis

• Instrumentation• Data collection• Data analysis

Motion Analysis Lab

Introduction

• What is motion analysis ?

• When and why do we need to analyze motion?

• What knowledge do we need before research?

Motion Analysis Lab

Introduction

• Kinematics (運動學）• Kinematics is concerned with the geometry of

motion and deal with relationships among displacement, velocity, acceleration, and time without any reference to the cause of motion

To describe the motions we see

Motion Analysis Lab

Introduction

• Kinetic (力動學 )• Kinetics deal with relationships among

forces, mass, and motion of the body, it is concerned with the cause of motion

To understand why the motions occur

force / torque

Motion Analysis Lab

• Anthropometry (人體測量學）• Involving body and limb measurements - mass of segment- location of mass center- segment length- center of rotation- angle of muscles- mass and cross-sectional area of muscles- moment of inertia

Introduction

Motion Analysis Lab

BM = Total Body Mass; BH = Body Height I = %I*Segment Mass*Segment Length2

Segment   L (%BH)

Mass (%BM)

Child < 14 y Mass (kg)

%LCoM (%BH)  (from distal joint)

Child < 14y %LCoM (%BH) 

%I * (in kg.m2)

Head 9.6 7.8 23.8-1.14*age 50 50 49.5

Torso 31.6 46.84 42.46-0.06*age 50 40.13+0.18*age 50.3

Upper arm 16.4 2.7 0.084*age+2.2 56.4 -0.028*age+55.7 32.2

Forearm 13.7 2.3 0.015*age+1.2 55 0.19*age+56.1 30.3

Hand 8.2 0.6 50 29.7

Thigh 25.4 9.9 0.364*age+6.634 56.7 53.42+0.115*age 32.3

Shank 23.3 4.6 0.122*age+3.809 57 55.74+0.3*age 30.2

Foot 11.7 1.4 0.015*age+1.87 50 56.49+0.186*age 47.5

Motion Analysis Lab

Introduction• Muscle and joint biomechanics

• Characteristics of muscle and joint - length-tension relationship - force-velocity relationship - joint type

Motion Analysis Lab

Introduction

• Electromyography (肌電圖）- the study of muscle electrical activities

providing information about the control and execution of voluntary movement

Motion Analysis Lab

Steps of motion analysis

Setting the purpose

Choosing the appropriate instrumentation

Data collection

Data analysis

Results and interpretation

Motion Analysis Lab

Motion Analysis Lab

Instrument_ kinematics

• （ Electro) goniometers (量角器）- a device for measuring joint angles

Motion Analysis Lab

Instrument_ kinematics

• Accelerometer (加速規）- a device that measures acceleration• types:

• strain gauge• piezoresistive• piezoelectric

Motion Analysis Lab

Instrument_ kinematics

• Imaging system• Cinematograph• digital video • charge-couple device (CCD) cameras:

- Motion analysis, VICON, Qualisys system

Motion Analysis Lab

Motion Analysis Lab

Eagle Digital RealTime System

• 1-2000 Hz selectable frame rates• Passive (retroreflective) markers

Motion Analysis Lab

EVa Real-Time Software (EVaRT)

• 3D Display• XYZ Graphs • Analog Graphs

Motion Analysis Lab

Instrument_ kinetic

• Force transducers

- measure the applied forces• types:

• Piezoresistive• Piezoelectric

Motion Analysis Lab

Instrumentation_ kinetic

• Force plate

- most commonly used type of force transducer

- measuring ground reaction force (GRF)• type:

• Strain gauge• Piezoelectric

Motion Analysis Lab

Instrumentation_ kinetic

• Kistler force plate

Motion Analysis Lab

Instrumentation_ kinetic

• Pressure sensor

Motion Analysis Lab

Instrument_ EMG

• Types:

- Surface EMG

- Wire EMG

- Needle EMG

Motion Analysis Lab

Steps of motion analysis

Setting the purpose

Choosing the instrumentation (kinematics, kinetic, EMG…..)

Data collection

Data analysis

Results and interpretation

Motion Analysis Lab

Data collection

• Calibration- to define the global coordinate system

Motion Analysis Lab

Data collection

• Preparation- measurements of basic data- placement of EMG electrodes - marker attachment on the landmark (marker set)- others

Motion Analysis Lab

Data collection• Placement of EMG electrodes

• Others: setting the appropriate mode - sampling rate- collection time- amplify….

Motion Analysis Lab

Steps of motion analysis

Setting the purpose

Choosing the instrumentation (kinematics, kinetic, EMG…..)

Data collection

Data reduction & analysis

Results and interpretation

Motion Analysis Lab

Data reduction & analysis

• Signal output

• Signal processing- data smoothing- interpolation- filter:low pass, band pass, high pass filter…...- re-sampling

• Setting the appropriate parameters

Motion Analysis Lab

Planes of Motion: 1 = Frontal plane 2 = Sagittal plane 3 = Transverse plane

Motion Analysis Lab

Data analysis• Calculation

- kinematics • Translation and Rotation of different coordinate

systems

Step 1: compute b Step 2: compute a Step 3: compute g

Resolve the joint angles:

Motion Analysis Lab

Data analysis

• Calculation • kinetic(ground reaction force, joint moment)

• Inverse dynamics

• EMG:• Rectified• Linear envelope• Integrated……..

Motion Analysis Lab

Take home message• How to choose the appropriate instrument?

- according to the research purpose- understanding the pros and cons

• How to collect data well?- following the manuscript- setting the appropriate mode

• What should be noticed in data analysis? - avoid distortion after signal processing - understanding the limitation and problems of different computing method

• What should be noticed while reading the report?- does the result make sense?

TAKE A BREAK

Motion Analysis Lab

• Part II : Applications• Projects in motion analysis laboratory• Gait analysis• Clinical applications• Sports medicine

Motion Analysis Lab

Gait analysis

• Bipedal locomotion, or gait, is a functional task requiring complex interactions and coordination among most of the major joints of the body, particularly of the lower extremity.

Motion Analysis Lab

Anatomical considerations_ hip joint

• flexion-extension occurs about a mediolateral axis. • adduction-abduction occurs about an anteroposterior axis.• internal-external rotation occurs about a longitudinal axis.

Motion Analysis Lab

Anatomical considerations_ knee joint

• 3 degrees of freedom of angular rotation are also possible during gait.

• The primary motion is knee flexion-extension.• Knee internal-external rotation and adduction-

abduction may also occur, but with less consistency and amplitude among healthy individuals owing to soft tissue and bony constraints to these motion.

Motion Analysis Lab

Anatomical considerations_ ankle and foot

• Ankle motion is restricted by the morphological constraints of the talocrural joint, which permits only plantarflexion (extension) and dorsiflexion (flexion).

• In gait analysis as a rigid segment, the foot is required to act as both a semirigid structure and a rigid structure that permits adequate stability

Motion Analysis Lab

Gait Cycle• Stance phase:60%, including foot flat, midstance,

terminal stance, and pre-swing.• Swing phase: 40%, including initial swing, midswing,

and terminal swing.

Motion Analysis Lab

Time-distance variable

Ranges of normal values for time-distance parameters of adult gait at free walking velocity

Stride or cycle time 1.0 to 1.2 sec

Stride or cycle length 1.2 to 1.9 m

Step length 0.56 to 1.1 m

Step width 7.7 to 9.6 cm

cadence 90 to 140 step/min

velocity 0.9 to 1.8 m/sec

Motion Analysis Lab

Motion Analysis Lab

Clinical Applications

• Musculoskeletal pathology• polio, muscle atrophy, amputation,

osteoarthritis rheumatoid arthritis, trauma• muscle weakness, restricted joint

mobility, pain• Upper motor neuron pathology

• cerebral palsy, stroke, brain trauma• combine spasticity, sensory disturbance,

error in control mechanisms

Chair-rise in Patients after Total Knee Arthroplasty

Fong-Chin Su, Kuo-An Lai, Wei-Hsien Hong

Clin Biomech 13:176-181, 1998

Motion Analysis Lab

Objectives

• To understand the biomechanics and compensatory mechanisms of chair-rise in patients after TKA.

• Functional evaluation of pre-op patients compared to the normal elderly.

Motion Analysis Lab

subject N age body height body weight (yr) (cm) (kg)

normal elderly

OA patient TKA patient

12

14*

12*

159.5 ± 6.9

154.5 ± 5.2

157.0 ± 5.7

61.0 ± 9.90

58.2 ± 10.5

73.3 ± 14.0

60.7±6.67 61.2 ± 7.60

64.8 ± 8.00

* : OA patients ( 10 bilateral, 4 unilateral )TKA patients ( 8 unilateral, 4 bilateral )

Subjects

Motion Analysis Lab

A/Dconverter computer

diskstorage

camerainterface

Experiment Setup

Motion Analysis Lab

Marker Set

Motion Analysis Lab

Sit-to-Stand

a b c d

a - b : flexion momentum phase b - c : momentum transfer phase c - d : extension phase

* 4 chair heights: 115%, 100%, 80%, 65% knee height

Motion Analysis Lab

115% 100% 80% 65%0

1

2

3

** *

#

Normal oldOATKA

Chair height as % of Knee-Heel Height*: P<0.05#:P<0.005

Dur

atio

n (s

)Duration of the STS

Motion Analysis Lab

115% 100% 80% 65%0

0.05

0.1

0.15

0.2

0.25

0.3

**

*

Normal oldOATKA

Chair Height as % of Knee-Heel Height*:P < 0.001

hori

zont

al d

ispl

acem

ent

(m)

COM displacement

Motion Analysis Lab

115% 100% 80% 65%0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

*

*

Normal oldOATKA

Chair Height as % of Knee-Heel Height*: P < 0.001

max

imal

ver

tica

l vel

ocit

y (m

/s)

Vertical velocity of COM

Motion Analysis Lab

115% 100% 80% 65%0

20

40

60

80

100

120

140 *

Normal old OA TKA Side Sound Side of TKA Patient

Chair Height as % of Knee-Heel Height*: P<0.001

max

imal

fle

xion

ang

le o

f hi

p (d

egre

es)

Angular changes_ hip joint

Motion Analysis Lab

115% 100% 80% 65%0

20

40

60

80

100

120

140 *

Normal old OA TKA Side Sound Side of TKA Patient

Chair Height as % of Knee-Heel Height *: P < 0.01

max

imal

fle

xion

ang

le o

f kn

ee (

degr

ees)

Angular changes_ knee joint

Motion Analysis Lab

115% 100% 80% 65%0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

*

Normal old OA TKA Sound Side of TKA Patient

Chair Height as % Knee-Heel Height*:P < 0.01

max

imal

fle

xion

mom

ent

of h

ip

( %

of

body

wei

ght

x bo

dy h

eigh

t)

Joint flexion moment_ hip

Motion Analysis Lab

115% 100% 80% 65%0

1

2

3

4

5

6 Normal old OA TKA Side Sound Side of TKA Patient

Chair Height as % of Knee-Heel Height*: P < 0.01; #: P < 0.001

max

imal

fle

xion

mom

ent

of k

nee

(% o

f bo

dy w

eigh

t x

body

hei

ght)

*#*

Joint flexion moment_ knee

Motion Analysis Lab

115% 100% 80% 65%0

1

2

3

4Normal old OA TKA Sound Side of TKA Patient

Chair Height as % of Knee-Heel Height

max

imal

dor

sifl

exio

n m

omen

t of

ank

le(%

of

body

wei

ght

x bo

dy h

eigh

t)

Joint flexion moment_ ankle

Motion Analysis Lab

TKA patient

elderly

1.97 sec

1.81 sec

seat-off

seat-off

41%

49%

59%

51%

Motion Analysis Labelderly

TKA patient

Fh

Fk

Fa

Motion Analysis Lab

elderly TKA patient

COM COM

Joint Moment

Motion Analysis Lab

Conclusion

• TKA patient has larger displacement and horizontal velocity of COM compared to the normal elderly.

• No significant difference in angles of three joints.

• TKA patients has special pattern in nearly knee full extension.

• TKA has larger ankle and hip moments. Increased chair height, decreased joint angles and moments.

Common Abnormal Kinetic Patterns of the Knee in Gait in Cerebral Palsy

C.J. Lin, L.Y. Guo, F.C. Su, Y.L. Chou

Gait & Posture, 11:224-232, 2000

Motion Analysis Lab

Objectives

• To investigate the detailed kinetic characteristics of each abnormality.

• 23 children suffering from cerebral palsy with spastic diplegia, were recruited• 46 limbs into four groups:

• jump (n = 7)• crouch (n = 8) • recurvatum (n = 14) • mild (n = 17)

Motion Analysis Lab

Crouch Gait• Results show that crouch gait usually has larger

and long-lasting knee extensor moments at stance. • This reveals that rectus femoris has relatively

high activation.

Motion Analysis Lab

Recurvatum Knee

• Knee flexor moments are large and long-lasting during stance.

The biceps femoris muscle shows less activation in EMG

the soft tissue behind the knee joint provides this flexor moment. This may result in worse recurvatum knee due to overstretch by the external forces.

Motion Analysis Lab

Knee Angle

GAIT CYCLE %

0 20 40 60 80 100

0

10

20

30

40

50

60

70

80E

XT

FL

EX

Jump

Recurvatum

Crouch

Mild

Normal

(Deg

ree)

Motion Analysis Lab

Knee Joint Moment

Gait Analysis After Ankle Arthrodesis

W.L. Wu, F.C. Su, Y.M. Cheng, P.J. Huang, P.J. Chou, Y.L. Chou, C.K. Chou

Gait & Posture, 11:54-61, 2000

Motion Analysis Lab

Aims

• To employ a computerized motion analysis system to identify the effect of ankle arthrodesis on three-dimensional kinematic and kinetic behaviors of the rear and fore foot and muscle activities of the lower extremity during level walking.

Motion Analysis Lab

Subjects• Patients: 10 (7 males and 3 females)

• with single-side solid arthrodesis of the ankle performed due to trauma, degenerative osteoarthritis or rheumatic arthritis, were recruited for this study.

• The mean age was 39.6 years old (13 to 64 y/o).

• The mean duration of follow-up after arthrodesis was 1.7 years (0.5 to 4 years).

• Controls: 10 normal subjects, mean age 28.8 yrs (20 to 35 y/o)

Motion Analysis Lab

Markers set & coordinate system

xf

zf

xh xt

xf

xt

xh

zt

zh

yfytyh

Motion Analysis Lab

Experiments

Motion Analysis Lab

Spatiotemporal parameters

patients controls

Cadence(steps/min)

106.9 11.7 102.3 6.6

Swing/stance ratio 0.61 0.08(affected side) **

0.69 0.05 (unaffected side) **

0.67 0.07

Values shown are mean 1 standard deviation (Mann-Whitney Test).

Motion Analysis Lab

RANGE OF MOTION

range of motion (degrees)

Joint Movement affected side ofpatients

controls

**Dorsiflexion/Plantarflexion 10.8 4.8 16.3 3.7

Inversion/Eversion 10.8 4.6 7.1 2.3hindfoot

* Internal/External rotation 13.8 3.2 10.6 3.8

**Dorsiflexion/Plantarflexion 18.8 3.9 13.4 3.8

Valgus/Varus 14.0 3.5 11.1 2.1forefoot

* Abduct/Adduct 12.6 3.5 6.9 3.9*: p<0.05 (Mann-Whitney test); **: p<0.01

Motion Analysis Lab

Hindfoot Motion

Motion Analysis Lab

Forefoot Motion

Motion Analysis Lab

Ground Reaction Force

0 10 20 30 40 50 60 70 80 90 1000

50

100

150

% Stance Phase

% B

W

F1-T1

F2-T2

F3-T3

Ankle arthrodesisNormal

VerticalForce

white: no changered: increasegreen: decrease

Motion Analysis Lab

Ground Reaction Force

0 10 20 30 40 50 60 70 80 90 100

-20

0

20

% Stance Phase

% B

W

F4-T4

F5-T5

F6-T6

Fore-aft force

Ankle arthrodesisNormal

white: no changered: increasegreen: decrease

Motion Analysis Lab

Ground Reaction Force

0 10 20 30 40 50 60 70 80 90 100-10

0

10

% B

W

% Stance Phase

F7-T7

F8-T8 F9-T9

Medial-lateralforce

Ankle arthrodesisNormal

white: no changered: increasegreen: decrease

Motion Analysis Lab

Pressure distribution in stance phase

0 20 40 60 80 100

0

2

4

6

8

10

12

Area1

Nt/

cm2

100% stance phase

0 20 40 60 80 100

0

2

4

6

8

10

12

Area 2 Affected side Unaffected side Control group

Nt/

cm2

100% stance phase

0 20 40 60 80 100

0

2

4

6

8

10

12

Area 3

Nt/

cm2

100% stance phase

0 20 40 60 80 100

0

2

4

6

8

10

12

Area 4

Nt/

cm2

100% stance phase

1 2

3 4

Motion Analysis Lab

0 20 40 60 80 100

0

2

4

6

8

10

12

Area 5N

t/cm

2

100% stance phase0 20 40 60 80 100

0

2

4

6

8

10

12

Area 6 Affected side Unaffected side Control group

Nt/

cm2

100% stance phase

0 20 40 60 80 100

0

2

4

6

8

10

12

Area 7

Nt/

cm

2

100% stance phase

0 20 40 60 80 100

0

2

4

6

8

10

12

Area 8

Nt/

cm2

100% stance phase

0 20 40 60 80 100

0

2

4

6

8

10

12

Area 9

Nt/

cm

2

100% stance phase

0 20 40 60 80 100

0

2

4

6

8

10

12

Area 10

Nt/

cm2

100% stance phase

5 6 7

8 9 10

Motion Analysis Lab

Conclusion - motion

• Hindfoot• No 2nd rocker• Increased eversion and external rotation

throughout whole gait cycle.• Forefoot

• Increased third rocker motion at toe-off.• Increased adduction• Significant increased eversion at toe-off.

Motion Analysis Lab

Rage of Motion

• Ankle fusion causes• decrease of sagittal movements of

hindfoot.• increase of transverse movements of

hindfoot.• increase of forefoot motion in three

planes.

Motion Analysis Lab

Ground Reaction Force

• Decreased loading rate.• Weak body support in midstance and push-

off in preswing.• Smaller fore-aft shear force.• Greater lateral shear force.

Motion Analysis Lab

Force and Pressure in 10 Masks

• Affected side :• pressure and force in rearfoot, forefoot

and toe areas lack of the force absorption and forward progression

• pressure and force in two midfoot areas supposing pronated gait

Biomechanical Evaluation of New Type Stair Climbing Machine (S770)

Motion Analysis Lab

Purpose

• To investigate the biomechanics of new type stair climbing machine (S770).

(1) kinematics:- movement range of hip, knee, and ankle joints(2) kinetics: - foot contact force- joint moment(3) muscle activities

Motion Analysis Lab

Methods_ subject

• 12 healthy young adults

- 2 females, 10 males

- Age: 24.5±1.2 y/o

- Body height: 171.1±5.5 cm

- Body weight: 64.0±9.6 kg

Motion Analysis Lab

Methods_ instrumentation

• 6-axis load cell:

- embedded in the left foot pedal

• Surface EMG system:

- MA 300

• Motion analysis system:

- 8 Eagle digital cameras

- 15 reflective markers

Motion Analysis Lab

Methods_ EMG

Adductor AbductorHamstringRF,VM,VL

Tibialis anterior and Peroneus longus Gastrocnemius

Motion Analysis Lab

Motion Analysis Lab

Methods _ data collection

• Four conditions:

- step to end range, trunk static

- step to end range, trunk shift

- step at selected range, trunk static

- step at selected range, trunk shift• Stepping at selected speeds• 3 trials/condition, 15 secs/trial

Motion Analysis Lab

Animation_ step to end range

Trunk static Trunk shift

Motion Analysis Lab

Animation_ trunk static

Step to end range Step at selected range

Motion Analysis Lab

Results_ joint angle

Flex(+)

Ext(-)

Abd(+)

Add(-)

PF(+)

DF(-)

Abd(+)

Add(-)

Motion Analysis Lab

Result_ foot contact force

Motion Analysis Lab

Results_ foot contact force

foot contact force

0

0.2

0.4

0.6

0.8

1

1.2

(BW

) ML

AP

Vertical

Trunk shift

End range

Trunk shift

Selected range

Trunk static

End range

Trunk static

Selected range

• foot contact force:

Trunk shift > Trunk static

• Stair climbing machine (S770) < walking and normal stair climbing ( > 1 BW)

Motion Analysis Lab

Results_ joint moment

(+) abd

Motion Analysis Lab

Results_ joint moment

PF(+)

DF(-)

flex(+)

ext(-)

flex(+)

ext(-)

Motion Analysis Lab

Results _ muscle activities

0 50 100 150 200 250 3000

50

100Left hip flexion(+)/extension(-)

Degr

ee

0 50 100 150 200 250 300-20

020

Left hip abd(+)/add(-)

Degr

ee

0 50 100 150 200 250 300-20

020

Left hip IR(+)/ER(-)

Degr

ee

0 500 1000 1500 2000 2500 30000

50ABD

% o

f MVC

0 500 1000 1500 2000 2500 30000

50ADD

% o

f MVC

Motion Analysis Lab

Results_ muscle activities

0 50 100 150 200 250 30020

40

60Left knee flexion(+)/extension(-)

Degre

e

0 50 100 150 200 250 300-10

0

10Left knee abd(+)/add(-)

Degre

e

0 50 100 150 200 250 300-20

020

Left knee IR(+)/ER(-)

Degre

e

0 500 1000 1500 2000 2500 30000

2040

RF

% o

f M

VC

0 500 1000 1500 2000 2500 30000

2040

VM

% o

f M

VC

0 500 1000 1500 2000 2500 30000

20

40VL

% o

f M

VC

0 500 1000 1500 2000 2500 30000

20

40HA

% o

f M

VC

Thanks for your attention ~