Motion Analysis
Summer Course
Speaker: Yi-Jung Tsai
Date: 2011/07/13
Motion Analysis Laboratory
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
Introduction
• 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
Motion Analysis Lab
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
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
Foot
11.7
1.4
0.015*age+1.87
50
56.49+0.186*age 47.5
50
29.7
30.2
BM = Total Body Mass; BH = Body Height
I = %I*Segment Mass*Segment Length2
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
Resolve the joint angles:
Step 1: compute b
Step 2: compute a
Step 3: compute g
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?
Motion Analysis Lab
TAKE A BREAK
• 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 adductionabduction 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
Motion Analysis Lab
Chair-rise in Patients after Total
Knee Arthroplasty
Fong-Chin Su, Kuo-An Lai, Wei-Hsien Hong
Clin Biomech 13:176-181, 1998
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
Subjects
subject
N
age
(yr)
body height
(cm)
body weight
(kg)
normal elderly
12
60.7±6.67
159.5 ± 6.9
61.0 ± 9.90
OA patient
14*
61.2 ± 7.60
154.5 ± 5.2
58.2 ± 10.5
TKA patient
12*
64.8 ± 8.00
157.0 ± 5.7
73.3 ± 14.0
*:
OA patients ( 10 bilateral, 4 unilateral )
TKA patients ( 8 unilateral, 4 bilateral )
Motion Analysis Lab
Experiment Setup
A/D
converter
computer
disk
storage
camera
interface
Motion Analysis Lab
Marker Set
Motion Analysis Lab
Sit-to-Stand
a
b
a - b : flexion momentum phase
b - c : momentum transfer phase
c - d : extension phase
c
d
* 4 chair heights:
115%, 100%, 80%, 65% knee height
Motion Analysis Lab
Duration of the STS
#
3
*
*
Duration (s)
*
2
Normal old
OA
TKA
1
0
115%
100%
80%
65%
Chair height as % of Knee-Heel Height
*: P<0.05
Motion Analysis Lab
#:P<0.005
COM displacement
horizontal displacement (m)
0.3
*
*
0.25
*
0.2
Normal old
OA
TKA
0.15
0.1
0.05
0
115%
100%
80%
65%
Chair Height as % of Knee-Heel Height
*:P < 0.001
Motion Analysis Lab
Vertical velocity of COM
maximal vertical velocity (m/s)
0.8
0.7
*
0.6
*
0.5
Normal old
OA
TKA
0.4
0.3
0.2
0.1
0
115%
100%
80%
65%
Chair Height as % of Knee-Heel Height
*: P < 0.001
Motion Analysis Lab
Angular changes_ hip joint
maximal flexion angle of hip (degrees)
Normal old
OA
TKA Side
Sound Side of TKA Patient
140
*
120
100
80
60
40
20
0
115%
100%
80%
65%
Chair Height as % of Knee-Heel Height
*: P<0.001
Motion Analysis Lab
Angular changes_ knee joint
Normal old
OA
TKA Side
Sound Side of TKA Patient
maximal flexion angle of knee (degrees)
140
*
120
100
80
60
40
20
0
115%
100%
80%
65%
Chair Height as % of Knee-Heel Height Motion
*: P < 0.01
Analysis Lab
Joint flexion moment_ hip
maximal flexion moment of hip
( % of body weight x body height)
6
Normal old
OA
TKA
Sound Side of TKA Patient
*
5
4
3
2
1
0
115%
100%
80%
65%
Chair Height as % Knee-Heel Height
Motion Analysis Lab
*:P < 0.01
Joint flexion moment_ knee
maximal flexion moment of knee
(% of body weight x body height)
6
Normal old
OA
TKA Side
Sound Side of TKA Patient
5
*
#
*
4
3
2
1
0
115%
100%
80%
Chair Height as % of Knee-Heel Height
*: P < 0.01; #: P < 0.001
65%
Motion Analysis Lab
maximal dorsiflexion moment of ankle
(% of body weight x body height)
Joint flexion moment_ ankle
4
Normal old
OA
TKA
Sound Side of TKA Patient
3
2
1
0
115%
100%
80%
65%
Chair Height as % of Knee-Heel Height
Motion Analysis Lab
TKA patient
59%
41%
1.97 sec
seat-off
49%
51%
elderly
1.81 sec
seat-off
Motion Analysis Lab
Fh
Fk
TKA patient
Fa
elderly
Motion Analysis Lab
Joint Moment
COM
elderly
COM
TKA patient
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.
Motion Analysis Lab
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
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
• 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.
Recurvatum
Knee
Motion Analysis Lab
FLEX
Knee Angle
80
70
Crouch
60
Jump
Mild
EXT
(Degree)
50
Recurvatum
40
Normal
30
20
10
0
0
20
40
60
GAIT CYCLE %
80
100
Motion Analysis Lab
Knee Joint Moment
Motion Analysis Lab
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
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
yt yf
yh
xh xt
xf
zt
zf
zh
xt
xh
xf
Motion Analysis Lab
Experiments
Motion Analysis Lab
Spatiotemporal parameters
Cadence
(steps/min)
patients
controls
106.9  11.7
102.3  6.6
Swing/stance ratio 0.61  0.08(affected side) **
0.67  0.07
0.69  0.05 (unaffected side) **
Values shown are mean  1 standard deviation (Mann-Whitney Test).
Motion Analysis Lab
RANGE OF MOTION
range of motion (degrees)
hindfoot
Joint Movement
affected side of
patients
controls
**Dorsiflexion/Plantarflexion
10.8 4.8
16.3  3.7
Inversion/Eversion
10.8  4.6
7.1  2.3
* Internal/External rotation
13.8  3.2
10.6  3.8
18.8  3.9
13.4 3.8
14.0 3.5
11.1  2.1
12.6  3.5
6.9  3.9
**Dorsiflexion/Plantarflexion
forefoot
Valgus/Varus
* Abduct/Adduct
*: 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
Ankle arthrodesis
Normal
150
F3-T3
F1-T1
100
% BW
Vertical
Force
F2-T2
50
0
white: no change 0
red: increase
green: decrease
10
20
30
40
50
60
70
80
90
100
% Stance Phase
Motion Analysis Lab
Ground Reaction Force
Fore-aft
force
20
% BW
Ankle arthrodesis
Normal
0
F5-T5
F4-T4
F6-T6
-20
0
white: no change
red: increase
green: decrease
10
20
30
40
50
60
70
80
90
100
% Stance Phase
Motion Analysis Lab
Ground Reaction Force
Ankle arthrodesis
Normal
% BW
Medial-lateral
force
10
F9-T9
F8-T8
0
F7-T7
-10
0
10
white: no change
red: increase
green: decrease
20
30
40
50
60
70
80
90
100
% Stance Phase
Motion Analysis Lab
Pressure distribution in stance phase
Area1
Area 2
12
10
10
8
8
Nt/cm
Nt/cm
2
2
12
Affected side
Unaffected side
Control group
6
6
4
4
2
2
0
0
0
20
40
60
80
0
100
20
40
80
100
3
4
Area 4
Area 3
12
12
10
10
8
8
1 2
2
2
6
Nt/cm
Nt/cm
60
100% stance phase
100% stance phase
4
6
4
2
2
0
0
0
20
40
60
100% stance phase
80
100
0
20
40
60
80
100
100% stance phase
Motion Analysis Lab
Area 5
Area 6
12
10
10
8
8
2
6
Nt/cm
Nt/cm
2
12
Affected side
Unaffected side
Control group
4
6
4
2
2
0
20
40
60
80
100
0
20
40
100% stance phase
80
100
Area 8
12
12
10
10
8
8
10
5 6 7
2
2
6
Nt/cm
Nt/cm
60
9
100% stance phase
Area 7
6
4
4
2
2
0
0
0
20
40
60
80
100
0
20
100% stance phase
40
60
80
100
80
100
100% stance phase
Area 9
Area 10
12
10
10
8
8
2
12
Nt/cm
2
Nt/cm
8
0
0
6
6
4
4
2
2
0
0
0
20
40
60
100% stance phase
80
100
0
20
40
60
100% stance phase
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 pushoff 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
Motion Analysis Lab
Biomechanical Evaluation of New Type
Stair Climbing Machine (S770)
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
• Motion analysis system:
• 6-axis load cell:
- 8 Eagle digital cameras
- embedded in the left foot pedal
- 15 reflective markers
• Surface EMG system:
- MA 300
Motion Analysis Lab
Methods_ EMG
RF,VM,VL
Hamstring
Tibialis anterior and Peroneus longus
Abductor
Adductor
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
PF(+)
Flex(+)
DF(-)
Ext(-)
Abd(+)
Abd(+)
Add(-)
Add(-)
Motion Analysis Lab
Result_ foot contact force
Motion Analysis Lab
Results_ foot contact force
foot contact force
1.2
• foot contact force:
(BW)
1
0.8
ML
0.6
AP
0.4
Vertical
Trunk shift > Trunk static
0.2
0
Trunk shift
Trunk shift
Trunk static
Trunk static
End range
Selected range
End range
Selected range
• Stair climbing machine (S770) < walking and normal stair climbing ( > 1
BW)
Motion Analysis Lab
Results_ joint moment
(+) abd
Motion Analysis Lab
Results_ joint moment
flex(+)
flex(+)
PF(+)
ext(-)
ext(-)
DF(-)
Motion Analysis Lab
Results _ muscle activities
% of MVC
% of MVC
Degree
Degree
Degree
Left hip flexion(+)/extension(-)
100
50
0
0
50
100
150
200
Left hip abd(+)/add(-)
250
300
0
50
100
150
200
Left hip IR(+)/ER(-)
250
300
0
50
100
150
ABD
200
250
300
0
500
1000
1500
ADD
2000
2500
3000
0
500
1000
1500
2000
2500
3000
20
0
-20
20
0
-20
50
0
50
0
Motion Analysis Lab
Results_ muscle activities
% of MVC
% of MVC % of MVC % of MVC
Degree
Degree
Degree
Left knee flexion(+)/extension(-)
60
40
20
10
0
-10
20
0
-20
40
20
0
40
20
0
40
20
0
0
50
100
150
200
Left knee abd(+)/add(-)
250
300
0
50
100
150
200
Left knee IR(+)/ER(-)
250
300
0
50
100
150
RF
200
250
300
0
500
1000
1500
VM
2000
2500
3000
0
500
1000
1500
VL
2000
2500
3000
0
500
1000
1500
HA
2000
2500
3000
0
500
1000
1500
2000
2500
40
20
0
3000
Motion
Analysis Lab
Thanks for your attention ~