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This is to certify that the

thesis entitled

TWO-DIMENSIONAL DRAFTING TEMPLATE AND THREE-DIMENSIONAL
COMPUTER MODEL REPRESENTING THE AVERAGE ADULT MALE IN
AUTOMOTIVE SEATED POSTURES

presented by

Neil James Bush

has been accepted towards fulﬁllment
of the requirements for

Masters degree in Mechanlcs

 

 

 

 

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MSU Is An Afﬁrmative Action/Equal Opportunity lndltution
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TWO-DIMENSIONAL DRAFTING TEMPLATE AND THREE-DIMENSIONAL
COMPUTER MODEL REPRESENTING THE AVERAGE ADULT MALE IN
AUTOMOTIVE SEATED POSTURES

BY

Neil James Bush

A THESIS

Submitted to
Michigan State University
in partial fulfillment of the requirements

for the degree of

MASTER OF SCIENCE

Department of Material Science and Mechanics
1 992

ABSTRACT
TWO-DIMENSIONAL ORAFTINO TEMPLATE AND THREE-DIMENSIONAL
COMPUTER MODEL REPRESENTING THE AVERAGE ADULT MALE IN
AUTOMOTIVE SEATED POSTURES
By

Neil James Bush

A growing interest for automobile customers is the comfort Of the seats in
their cars. The automotive seats should fit the body shapes Of people and move
the way people move in seated postures.

This thesis describes the development of a template (JOHN 2-D) that
represents the skeletal framework Of the human body for the average adult male
in seated postures. JOHN 2-D represents the body with a skull, thorax, pelvis
and a gear system to represent the cervical and lumbar segments of the spine.
JOHN 2-D moves the thorax relative to the pelvis with lumbar articulation and
moves the skull relative to the thorax with cervical spine articulation.

The torso Of the average adult male was investigated tO develop a
representative outer body surface Of the back Of an occupant in an automobile
seat. This outer body surface was created on a three-dimensional computer
model (JOHN 3-D) Of the human skeleton. The vertebral column and back
muscles were added to the skeleton and then a skin layer was created over the
back surface Of the model. A motion program was developed tO locate
JOHN 53-0 in different body postures. Then a skin was created for the model in
these postures.

It was concluded that the work presented in this thesis can be used to
compare existing automotive seat designs with human body postures and

develop new seat designs to better fit the average adult male body.

DEDICATION

To my parents for their guidance and support in everything that l have
ever set out to do. TO my fiancee who gave me the inspiration to obtain this goal
because without her it would not have been a goal at all.

Thank you Tamara

ACKNOWLEDGEMENTS

The author would like to express his sincerest gratitude tO the following
people, for their efforts, advice, and encouragement in the completion Of this
thesis.

TO my co-workers and friends for their help and support: Cathy Boomus,
Robert Boughner, Richard Canole, Amanda Centilli, Bing Deng and Mark Sochor.
Each Of these people played an important role in the completion Of this thesis.

To Johnson Controls Inc. for their generous funding of this research
project.

To my graduate committee: Dr. Roger Haut and Dr. Robert Soutas-Little.
Thank you for reviewing my work.

To my graduate advisor: Dr. Robert P. Hubbard for your friendship and
guidance these past two years. This was an accomplishment that I am very

proud of and you made it possible for me. Thank you.

iv

TABLE OF CONTENTS

Page

LIST OF TABLES ........................................ vi

LIST OF FIGURES ....................................... vii

1. BACKGROUND AND OBJECTIVES .......................... 1

2. ARTICULATED 2-D TEMPLATE ............................ 11

2.1 Introduction ..................................... 11

2.2 Methods ........................................ 12

2.2.1 Lumbar Linkage ............................. 14

2. 2. 2 Body Components ............................ 14

2. 2. 3 Sprocket Articulation .......................... 14

2. 2. 4 Cervical Linkage ............................. 16

2. 2. 5 Spinal Curvature Scale ......................... 19

2. 2. 6 T ree Link System ............................ 19

2.3 Results and Discussion ............................. 22

2.3.1 Comparing the One Link Template to the Computer Model. .22

2. 3. 2 Comparing the Three Link Template to the Computer Model .22

2. 3. 3 Using JOHN 2- D to Represent Different Body Pastures. .23

2. 3. 4 Comparing JOHN 2- D to the SAE Template ........... 28

3. 3-D HUMAN OUTER BODY CONTOURS ...................... 31

3.1 Introduction ..................................... 31

3.2 Methods ....................................... 31

3.2.1 Computer System Software ...................... 31

3. 2. 2 The Vertebral Column ......................... 32

3. 2. 3 Muscle Modeling ............................. 32

3. 2. 4 Motion Program ............................. 44

3. 2. 5 Generating Skin ............................. 45

3.3 Results and Discussion ............................. 55

3.3.1 Comparing JOHN 3-D with the UM-TRI Study .......... 55

4. CONCLUSION ....................................... 61
APPENDICES

A. Motion Program ................................... 63

B. Spinal Joint Center Coordinates ......................... 81

C. Table Of Skin Points ................................ 84

D. JOHN 3-D Cross Sections ............................ 90

BIBLIOGRAPHY ........................................ 100

LIST OF TABLES

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1. Skin Points for TLC= 0° ............................... 84
2. Skin Points for TLC= -10° .............................. 85
3. Skin Points for TLC= 10° ............................... 86
4. Skin Points for TLC= 20° ............................... 87
5. Skin Points for TLC= 30° ............................... 88
6. Skin Points for TLC= 40° ............................... 89

vi

LIST OF FIGURES

519279 E299
1. THE SAE 2-D DRAFTING TEMPLATE ........................ 2
2. THE SAE 3-D H-POINT MACHINE .......................... 2
3. UM-TRI DRAWING FIFTIETH PERCENTILE ADULT MALE .......... 5
4. 2-D COMPUTER MODEL ................................ 7
5. 2-D COMPUTER MODEL WITH LUMBAR MOTION ............... 8
6. 3-D SKELETAL COMPUTER MODEL . .' ...................... 9
7. JOHN 2-D COMPUTER MODEL ........................... 13
8. JOHN 2-D FOR A RANGE OF LUMBAR MOTION ................ 15
9. SPROCKET AND CHAIN SYSTEM ......................... 17
10. a) ANODIZED ALUMINUM SPROCKET b) FLEXIBLE CHAIN ........ 18
11. THE JOHN 2-D TEMPLATE .............................. 20
12. THE THREE LINK TEMPLATE ............................ 21
13. JOHN 2-D WITH TLC= -10° to 40°, TRA=35° and HRA=O° .......... 244
14. JOHN 2-D WITH TRA=20° to 45°, TLC=O° and HRA=0° ............ 25
15. JOHN 2-D WITH TRA=20° to 45°, TLC=30° and HRA=O° ........... 26
16. JOHN 2-D WITH HRA= -10° to 15°, TLC=O° and TRA=25° .......... 27
17. COMPARING JOHN 2-D TO THE SAE TEMPLATE ............... 29
18. LUMBAR VERTEBRAE ................................. 33
19. THORACIC VERTEBRAL COLUMN ......................... 34
20. JOHN 3-D WITH THORACIC AND LUMBAR VERTEBRAE .......... 35

DETAILED DRAWING OF THE BACK MUSCLES ................ 37

N
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vii

22.
23.
24.
25.
26.
27.
28.
29.
30.
31 .
32.
33.
34.
35.
36.
37.
38.
39.
40.
41 .

42
43

45

THE ERECTOR SPINAE MUSCLES ......................... 38

LOCATION OF CROSS SECTIONS ON JOHN 3-D ............... 39
THE COMPUTER MODELED ERECTOR SPINAE MUSCLES ........ 41
THE OBLIOUUS ABDOMINIS MUSCLES ..................... 42
JOHN 3-D WITH MUSCLES REPRESENTED .................. 43
JOHN 3-D WITH LUMBAR MOTION ......................... 45
JOHN 3-D TORSO WITH CROSS SECTION LOCATIONS .......... 47
MESH OF CURVES FOR BACK SKIN ....................... 48
JOHN 3-D SKINNED AT TLC=O° ........................... 49
JOHN 3-D SKINNED AT TLC= -10° ......................... so
JOHN 3-D SKINNED AT TLC=10° .......................... 51
JOHN 3-D SKINNED AT TLC=20° .......................... 52
JOHN 3-D SKINNED AT TLC=30° .......................... 53
JOHN 3-D SKINNED AT TLC=40° .......................... 54
SIDE VIEW JOHN 3-D vs UM-TRI BODY FORM ................. 56
CROSS SECTIONS AT 400mm ............................ 57
CROSS SECTIONS AT 300mm ............................ 58
CROSS SECTIONS AT 200mm ............................ 59
CROSS SECTIONS AT 100mm ............................ 55
CROSS SECTIONS AT 0mm ............................. 55
JOHN 3-D TORSO SIDE VIEW WITH SECTIONS ................ 90
SECTION AT T5 ...................................... 91
SECTION AT T7 ...................................... 92
SECTION AT T9 ...................................... 93

viii

46
47
48
49
50
51

SECTION AT T1 1 ..................................... 94

SECTION AT L1 ...................................... 95
SECTION AT L2 ...................................... 96
SECTION AT L3 ...................................... 97
SECTION AT L4 ...................................... 98
SECTION AT L5 ...................................... 99

1. BACKGROUND AND OBJECTIVES

Automotive seat design is an important concern for both the automotive
companies and the automotive consumers. A key factor involved in seat design
is comfort, and the automotive seats Should be developed with that in mind. For
a comfortable seat, it is essential that the seat contour ﬁts people and allows
them to Change to a position compatible with the geometry of their bodies and
their movements. Human accommodation is important in the design process,
therefore, it is essential that the human body be well represented as an
anatomical structure.

Common practice in the automotive industry has been to design seats
using the tools developed by the Society of Automotive Engineers (SAE) [1].
SAE developed a two-dimensional (2-D) drafting template and a three-
dimensional (3-D) seat testing device (H-point machine) to represent the average
adult male torso. The 2-D template and 3-D testing device are shown in Figure 1
and Figure 2, respectively. These tools were originally intended only to ensure
consistent positioning of the occupant in the vehicle. They were not originally
intended to be an anatomical guide.

The 2-D SAE template is used as the starting point for automotive seating
design lay-out. The template locates the torso in the seat with two descriptive.
parameters:

1. H-point (intended by SAE to represent the location of the center of

rotation of the hip joint)

2. Seat Back Angle (SBA) measured from vertical to a line on the torso.

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The specifications of H-point and SBA are set by the interior package design;
these parameters are typically used for locating the occupant in the vehicle. Next
the seat designer positions the 2-D template in the design position and then
designs the seat around the template. Quite often the actual deflected seat
contour is taken directly from the 2-D template.

This design procedure relies on the template for the comfort and
positioning of the occupant. The SAE 2-D template is constructed to pivot the
torso about one point. the H-point; this configuration does not account for
motions of the pelvis and lumbar curvature. The SAE 2-D template locates the
occupant with a flat back in a slumped posture. The slumped posture occurs
when the lumbar spine is straight or bent into a kyphotic, convex curve as
opposed to an erect posture where the lumbar spine is in a lordotic, concave
curve. The lumbar spine curve is lordotic when the body is in a standing posture.
Chaffin and Anderson [2] say that a posture with the lumbar spine curved in a
lordotic manner can reduce lumbar spinal disc pressure. This disc pressure can
cause discomfort.

The 3-D SAE H-point machine is similar in configuration to the 2-D
template in that the torso pivots solely about the H-point and the lumbar region is
flat. This H-point machine is used in automotive seats to measure the location of
the H-point and SBA for comparison with the designed location. Seats have
been designed with side and lumbar supports to attempt to accommodate the
occupant in a comfortable position. When the H-point machine is used to test a
highly contoured seat with side and lumbar support it often locates the H-point
and reads the SBA at different values than were designed. This conflict in
measurements occurs because the one piece torso design of the SAE 20
template and the 3-D H-point machine do not articulate like the human pelvis, rib

cage and spinal column. There are two reasons for this:

4

1. WIth the H-point held in the correct position, the thorax rotates forward
at the top. This results in a smaller Seat Back Angle than was
predicted by the SAE 2-D template.

2. With the SBA set at the design value, the H-point is pushed further
forward in the seat by the lumbar support than was predicted by the
SAE 2-D template.

This testing could result in a incorrect design because there currently is no way to
represent and accommodate people in the design process.

By developing models that accurately represent the geometry of the body
and allow for posture change, improvements can be made in the design of
automotive seats. The design standards that guide seat design could be
reevaluated, then seats could be designed to support the body more comfortably.

An extensive study on human anthropometry in automotive seats has
been completed by the University of Michigan Transportation Institute (UM-TRI)
[3]. This study developed a 3-D set of data points taken from human test
subjects in a relaxed seated position. Each data point represents an anatomical
landmark or a digitized position taken from a casting made on the seat surface.
The points were averaged, then used with a study by Snyder et al. (Link Study)[4]
to locate the position of the bones which could not be palpated. This resulted in
a representation of the skeletal positions of the seated occupant. With this
information, UM-TRI [3] assembled full scale drawings, and molded body forms
which represent the 50th and 95th percentile adult male and the 5th percentile
adult female. The 50th percentile male is shown in Figure 3.

A 2-D computer model which incorporated the UM-TRI [3] data for the
50th percentile adult male was developed by Haas [5]. This model represented
the human body with three rigid segments, the skull, thorax and pelvis connected

by two ﬂexible links, the neck and lumbar regions. The work done by Haas

 

 

 

 

 

 

 

 

 

 

 

 

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6

determined that the pelvis represented in the UM-TRI study was not in the correct
location. The result of the Haas investigation [5] was to lower the pelvis and
lengthen the lumbar Spine leaving the thorax and skull in the original positions.
Figure 4 shows the 2—D computer model. This model was used with a computer
program which moves the thorax relative to the pelvis with lumbar articulation.
The program rotates the thorax about each of the six lumbar joint centers. Haas
examined different spine rotation distributions to compare with a uniform rotation
about each of the lumbar joint centers. The distributions by White and Panjabi [6]
and Allbrook [7] measured spinal motions with vertebral pairs. Haas also studied
idealized distributions with twice as much joint motion in the upper part or in the
lower part of the lumbar spine and some alternatives with motions in the thoracic
spine. Haas determined that uniform rotation about each of the lumbar joint
centers and no rotation in the thoracic region could be used to locate the thorax
relative to the pelvis. Figure 5 illustrates the 2-D model and its motion as
presented by Haas.

Further work has been done by Boughner [8] to develop a 3-D computer
model of the 50th percentile human skeleton. This research used the information
from UM-TRI [3] and other literature [8.9.10] to construct solid models of the
human bone structure. The 3-D model is shown in Figure 6. In addition to
modeling the 3-D skeleton, Boughner analyzed different methods of modeling
muscle shapes and hamstring muscle length.

The objectives of this thesis are to continue to work with the 2-D and 3-D
models and progress toward usable tools for representing the human body.

More specifically the objectives of this thesis are to:
(1) Develop an articulated 2-D template that can be used as a physical

representation of the 2-D computer model.

 

  

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10

(2) Further develop the 3-D model by adding components to better
represent the thoracic region (vertebrae, muscles and skin) and
project outer body contours.

(3) Develop motion programs for the 3-D model including the back
contours at different postural positions.

This thesis is structured into two sections: one devoted to the 2-D template

and its development and usage and the second devoted to the 3-D model

improvement and usage.

2. ARTICULATED 2-D TEMPLATE

2.1 Introduction

Automotive seats should be designed to comfonably accommodate the
occupant in the vehicle. The seat must be designed to ﬁt a range of human sizes
and a range of positions representative of the human skeletal motion. Studies
have been completed on the geometry of the body in seated positions, but
unfortunately this data has not been implemented into automotive seat
development. Computer aided design is commonly used to design automotive
seats, yet many automotive seat designs today are developed on drafting tables.
The designers need accurate up-to-date tools. It is the intention of this study to
develop a drafting template that represents the pelvis, thorax and head for the
50th percentile adult male and articulates according to the movement of the
human skeleton.

The two-dimensional template was created using the computer model
(JOHN 2-D) developed by Has [5]. JOHN 2-D is a two-dimensional
representation of the position and articulation of the pelvis, thorax, skull and
spinal column for a 50th percentile adult male. The reference posture for the
JOHN 2-D model has a straight lumbar spine. This initial posture was adopted
from the UM-TRI study [3] and then compared to additional studies that were
available [12.13.14]. The position of the pelvis was determined by the angle from
vertical to the line going from the Pubic Sympysis to the midpoint between the
right and left Anterior Superior Iliac Spine (ASIS) when viewed from the side; for

the initial position this angle is equal to 54°. The thorax location is determined by

11

12

the angle between the line going through the Suprasternale and the Substemale
and the vertical plane; this angle was equal to 38° for the initial posture. Haas [5]
determined that the initial posture with the UM-TRI pelvic and thoracic angles
should be used for JOHN 2-D. There are four important variables involved in
positioning the JOHN 2-D model:

1. Hip Joint Center (HJC) - location of the centers of the right and left hip
joints in the pelvis.

2. Total Lumbar Curvature (TLC) - measurement of lumbar spine
curvature defined as pelvic rotation minus thoracic rotation. Pelvic
and thoracic rotations are about an axis parallel to the positive
going, left lateral Y-axis and are positive according to the right hand
rule. TLC=0° corresponds to a straight lumbar spine.

3. Torso Recline Angle (TRA) - angle measured from vertical of the line
going through the top and bottom lumbar joint centers.

4. Head Rotation Angle (HRA) - angle measured between the eye-line and
the horizontal plane. The eye-line is a line, developed by Hubbard
and McLeod [15], going from the pupil of the eye rearward parallel
to the frankfort plane which is level when looking forward.

Figure 7 shows JOHN 2-D and each of these variables along with the coordinate

system set up by Haas [5].

2.2 Methods

The 2-D, side View geometry and spine articulation for JOHN 2-D was
developed by Haas [5]. It was this information that led to the development of a
template that could be used to represent the same information with hands-on

capabilities.

13

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14

2.2.1 Lumbar Linkage

With the pelvis held stationary, the computer model was examined for a
range of lumbar motion. It was then determined that the path of the top lumbar
joint center (T 1 2/L1) followed a 183 mm radius about the bottom lumbar joint
center (L5/S1). This measurement was taken at -10 and 40 degrees of lumbar
curvature with a deviation of 1 mm found for the full range of motion. Figure 8
shows JOHN 2-D for the range of lumbar motion and the radius measurements.
Because of this common distance, one bar could be used to connect the thorax
to the pelvis. This bar was designed to attach the thorax at the top lumbar
vertebral joint (T12/L1) to the pelvis at the bottom lumbar vertebral joint (LS/S1)

with a shoulder bolt at each position to permit smooth rotation about these points.

2.2.2 Body Components

The template was designed with three body components: the skull, rib
cage and pelvis. Each component was designed with the same shape and
dimensions as 2-D computer model Has [5] developed. The skull, rib cage and

pelvis were cutout of 1/4 inch Plexiglass.

2.2.3 Sprocket Articulation

The lumbar curvature for JOHN 2-D was developed using uniform rotation
about each of the lumbar joint centers. This rotates both the thorax and pelvis an
amount equal to one half TLC. Because of the assumption that each of the
lumbar vertebrae are the same size, the joint centers were equally spaced along
the vertebral column. With these two conditions, a two sprocket system was
developed with a chain connecting the two together. The sprockets were the

same size due to the uniform motion and spacing of the joint centers.

15

 

 

 

FIGURE 8: JOHN 2-D FOR A RANGE OF LUMBAR MOTION

16

The sprockets were made of anodized aluminum and had a pitch diameter of 1.6
inches. One sprocket was positioned at the top lumbar joint center and was
attached rigidly to the thorax; the other was positioned at the bottom lumbar joint
center and was attached rigidly to the pelvis. A flexible chain was used to
connect the two sprockets, and the Chain was twisted to create an equal rotation
in opposite directions. Figure 9 shows the sprocket and chain system used for
JOHN 2-D. The chain has a configuration similar to a ladder with evenly
distributed rungs connecting the Sides. The chain was made of polyurethane
with cable reinforcement for strength; this type was selected because of its
ﬂexibility and its minimal backlash characteristics. The chain was cut to the
correct length, determined by the distance between the sprockets and the
diameter of the sprockets, and then spliced together to form a continuous chain.
Figure 10 illustrates the sprocket and chain used for the JOHN 2-D template.
The bar was connected to the gears and bodies with shoulder bolts which
allowed smooth rotation. Wing nuts then tighten to lock the template in at the

desired positions.

2.2.4 Cervical Linkage

The linkage between the skull and thorax was also represented with a one
bar linkage. The vertebrae of the cervical spine as represented by UM-TRl [3]
were not of uniform size; the upper vertebrae are shorter. A motion pattern was
developed by Has [5] for uniform rotation at each cervical joint. However, this
cervical motion pattern has not been validated against measured neck motions.
It was determined that because of the size difference between each vertebrae
the cervical spine orientation could be represented with a 1 to 1.12 ratio of
rotation, thus, the template was constructed with a small sprocket (1.6 inch pitch

diameter) fixed to the Skull at the top cervical vertebral joint and a large sprocket

17

 

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(1.8 inch pitch diameter) fixed to the thorax at bottom cervical vertebral joint. The
chain used for the cervical linkage was the same as that described above for the
lumbar linkage. Again, the Chain was twisted to couple the sprockets in opposite

directions and with a 1 to 1.12 ratio of rotation.

2.2.5 Spinal Curvature Scale

A guide was developed to indicate the Total Lumbar Curvature (TLC).
The bar that connects the thorax to the pelvis was extended up past the top
lumbar joint center. Markings were then made on the bar and on the thorax to
indicate different values of TLC. The cervical linkage has the same type bar,
although at this time there are no markings to locate the amount of cervical
curvature. The head was simply positioned with the eye line horizontal for this

part of the study. Figure 11 is a picture of the JOHN 2-D template.

2.2.6 Three Link System

The one link system described in section 2.2.3 does not curve during
rotation like the actual lumbar spine. Consequently a second linkage system was
studied, one that would locate the thorax relative to the pelvis as well as move
with a curvature more like the human lumbar Spine. A system of three equal
length links was built with six sprockets. The three link template is shown in
Figure 12. Two sprockets positioned at the same places on the pelvis and
thorax, as that for the one link template. Two pairs of additional sprockets were
placed between the first two, both attached rigidly to a link between them. Two
more sprockets were then positioned on top of the two center gears. The second
sprocket down from the T12/L1 joint center was attached rigidly to a link which
pivots about the T12/L1 joint. The third sprocket down from the T12/L1 joint
center was attached rigidly to a link which pivots about the L5/S1 joint. The

20

 

FIGURE 11: THE JOHN 2-D TEMPLATE

21

 

THE THREE LINK TEMPLATE

FIGURE 12

22

sprocket at T12/L1 was coupled with the bottom sproket at the joint second from

the top. The sprocket at L5/Sf was coupled with the bottom sprocket at the joint

third from the top. The two top sprockets were coupled together. Sprockets with
a pitch diameter of 1.6 inches were used for the three linkage template just as for
the lumbar region of the one linkage template. The sprockets were coupled with

the same type of Chain as that used for the one bar linkage. A twist was made in
the chain between each sprocket; this created equal and opposite rotations of

each adjacent bar.

2.3 Results and Discussion

2.3.1 Comparing the One Link Template to the Computer Model

The one linkage template moves like the computer model to within 1mm
for a range of lumbar curvatures from -10° to 40°. This was determined
comparing the template to the drawings made by the computer model at different
TLC values and corresponding positions of the rib cage relative to the pelvis.
The one linkage template is a simple structure which represents a complex

motion of the human bone structure in the seated posture.

2.3.2 Comparing the Three Link Template to the Computer Model

The three link template moved with the curved articulation as was hoped,
but it did not have a consistent and accurate movement. WIth the addition of two
additional links and four sprockets, the system was too sloppy and uncontrolled.
For a complex system like this to work, a more precise mechanism would be
required. Refinement of the three link system was not continued because the

one link template functioned very well.

23

2.3.3 Using JOHN 2-D to Represent Different Body Postures

The JOHN 2-D model can be used to study a range of positions and the
relationships between each position. These relationships are representative of
human motion in seated postures, and this information can lead to innovative
designs when integrated into the design process. The JOHN 2-D template has
three degrees of freedom: Total Lumbar Curvature, Torso Recline Angle and
Head Rotation Angle. A series of scenarios were examined by changing one of
the variables while holding the other two constant. The first scenario was to
change the TLC from -10° to 40° of rotation, in increments of 10°, and the TRA
and HRA were held constant. Figure 13 illustrates the relationship of the TLC
with the TRA fixed at 35°, the HRA ﬁxed at 0° and the pelvis rotated about a line
through the right and left ischial tuberosities at the bottom of the pelvis. The
model predicts that there is a point that the thorax apparently pivots about in this
range of motion.

The next scenario was to change the TRA from 20° to 45°, in increments
of 5°, and keep the TLC and HRA constant. Figures 14 and 15 show this
relationship with TLC held at either 0° or 30°, respectively, while HRA was held at
0°. In this example, it was assumed that the pelvis rotates about the ischial
tuberosities. This situation can be correlated with keeping the occupant in one
posture and changing the back angle of the seat.

Finally, the HRA was changed, and both the TLC and TRA were held
constant. The HRA was ranged from -10° to 15°, in increments of 5°. The TLC
was held at 0° and the TRA at 25°. Figure 16 shows this scenario. The head
rotation is an approximate range of motion for the occupant looking at the
dashboard to looking at the visor. These different situations can be very useful

for the design of automotive seats.

 

 

 

 

 

FIGURE 13: JOHN 2-D WITH TLC=-10° to 40°,TRA=35° and HRA=0°

27

 

FIGURE 16: JOHN 2-D WITH HRA=-10° to 15°, TLC=0° and TRA=25°

28

If the seat designer can develop the seat to accommodate each of the positions,
then comfort can be achieved, assuming that accommodation of the occupants

preference of position is the key to their comfort.

2.3.4 Comparing JOHN 2-D to the SAE Template

The 2-D template will be referred to as JOHN 2-D, like the computer
model, for comparison with the SAE template. The SAE tools [1] represent the
pelvis as part of the upper leg segment and the torso as asingle piece with no
lumbar articulation. JOHN 2-D represents the upper leg, pelvis, lumbar and rib
cage segments as separate components and JOHN 2-D articulates each
component about anatomical joint center locations. For comparison to the SAE
2-D template with SBA=25° JOHN 2-D was subjectively positioned with TLC
equal to 10° and TRA equal to 25°. Then JOHN 20 was given a different
posture with TLC equal to 30° and TRA remaining equal to 25°. Figure 17 shows
these comparisons. By increasing lumbar curvature, the pelvis rotated fonIvard
and upward at the top, and the rib cage rotated forward at the bottom and
rearward at the top. Because of the SAE torso representation the SAE template
could not represent this change in posture due to lumbar articulation. Comparing
the two models: JOHN 2-D has the HJC to compare with the SAE H-point and
JOHN 2-D has the TRA to compare with the SAE SBA. JOHN 2-D then has the
ability to change the TLC which the SAE template cannot accomplish. WIth the
JOHN 2-D template set in an erect posture, with a lordotic lumbar curvature, it
conflicted with the seats designed with the SAE template. This conflict would
force the occupant to sit in a slumped posture, with a kyphotic lumbar curvature.
To support JOHN 2-D with an erect posture, the automotive seat should move
fonIvard at the pelvis, lumbar spine and lower rib cage areas and allow rearward

movement of the upper rib cage and shoulders. It is important to note that

29

JOHN 2-D
TLC=30°

JOHN 2-D
TLC=-10°

SAE TEMPLATE

 

 

 

FIGURE 17: COMPARING JOHN 2-D TO THE SAE TEMPLATE

30

JOHN 2-D can be positioned in the same posture as the SAE template, therefore,
it can be used with existing designs. The advantage of the JOHN 2-D template is

the lumbar mobility and what it can add to future automotive seat design.

3. 3-D HUMAN OUTER BODY CONTOURS

3.1 Introduction

Automotive seat comfort is dependent directly on the interaction between
the seat surface and the outer surface of the person's body who is in that seat.
The better the seat and body surfaces fit together the more comfortable the seat
will feel to the occupant. When these surfaces do not align correctly, muscle
fatigue and body soreness is often the result. A 3-D skeleton has been
developed by Boughner [8] to represent the fiftieth percentile adult male.
However, the spinal column was only represented as small spheres at the
vertebral joint centers as shown in Figure 6. This portion of the thesis is devoted
to the continued work on the 3-D skeleton, adding detail in the thoracic and
lumbar spines and the development of back surface contours. After developing a
detailed skeletal model with muscle groups, a representative skin contour can be

generated to fit over the model.

3.2 Methods
3.2.1 Computer System and Software

Each of the components developed to represent the fiftieth percentile adult
male was generated using a Hewlett Packard computer system and the SDRC
IDEAS software [16]. IDEAS includes a solid modeling package that allows the
user to create three-dimensional solid objects, assemble them, and integrate the

motions. Each component of the model was developed as a separate object.

31

32

These objects were then linked together to anatomically resemble a human

fiftieth percentile adult male skeleton (JOHN 3-D).

3.2.2 The Vertebral Column

The lumbar vertebrae were developed by using simple shapes to
resemble each vertebrae. Figure 18 illustrates one lumbar vertebrae and its
dimensions. The individual vertebrae were made with four pieces, each
constructed as objects and then merged together. The vertebral body was first
generated as a cylinder with an elliptical cross section. Second, the spinous
process was created as a simple six sided object and added to the vertebral
body. Finally, the transverse and accessory processes were created as five
sided objects and added to the vertebrae. The dimensions used to create the
lumbar vertebrae were taken from anatomical sections published by Koritke and
Sick [17]. For this thesis, it was assumed that each of the lumbar vertebrae could
be represented as one size and each was equally spaced between the lumbar
joint centers.

The thoracic vertebral column was assumed to move rigidly with the rib
cage. Because of this assumption, the thoracic vertebrae were represented by
their spinous processes only. The dimensions for the spinous processes were
taken from the UM-TRI study [3]. It was important to correctly represent the most
posterior point on each spinous process, but the shape and dimensions had less
importance for this model in the thoracic region. Figure 19 shows the thoracic

vertebral column. Figure 20 shows JOHN 3-D with the vertebral column.

3.2.3 Muscle Modeling
The back is made up of many muscles which all have a function in

maintaining posture when seated. It was important to determine which muscles

33

 

 

 

 

 

 

 

a) side view

 

C) oblique view

 

5) top view

FIGURE 18: LUMBAR VERTEBRAE a) slde view D) top View c) obIIque view

34

E
E
s
a

g

 

 

a) side view

c) oblique view

 

b) back View

FIGURE 19: THORACIC VERTEBRAL COLUMN

5) side view b) back view c) oblique view

35

 

FIGURE 20: JOHN 3-D WITH THORACIC AND LUMBAR VERTEBRAE

36

had direct effect on the outer surface contours. It was apparent by cadaver
studies that the erector spinae muscle group contributed the most to the surface
contours along both sides of the vertebral column. Figure 21 is a detailed
representation of the erector spinae muscles by Netter [18]. The erecfor spinae
muscle group is made up of three separate muscles, the Iongissimus, spinalis
and iliocosfalus. These muscles stretch along the spine from the skull to the
pelvis. On the sides of the torso the extemus and internus obliquus abdominis
muscles dominated the surface shapes; the obliquus abdominis muscles connect
the pelvis to the rib cage.

By reviewing Boughner’s work [8], it was determined that the erecfor
spinae would be most accurately modeled on the computer by constructing
profiles that resemble the shape of the muscle bellies and then by creating a
surface over each of these profiles. The profile method was Chosen over the
method of using ellipsoids to represent muscle groups. Ellipsoids would make
the model very complex and hard to manage. The erector spinae originates at
many positions along the vertebral column and rib cage as shown in Figure 22
taken from Stone and Stone [19]. The erecfor spinae was represented in two
sections, one for the thoracic region and one for the lumbar region. The thoracic
part of the erector spinae was rigidly connected along the rib cage and follows
the rib cage motion. Forthe lumbar region the iliocosfalus muscles of the erector
spinae group bridge from the rib cage to the pelvis as shown in Figure 22.
Therefore, the lumbar part lengthens and shortens when the posture is slumped
and erect, respectively.

The first step in creating the erector spinae muscles was to make
horizontal cross section plots of the 3-D computer model (JOHN 3-D) along the
torso. Figure 23 indicates the location of each cross section. Each of these plots

was compared with sections from Koritke and Sick [17] to determine

37

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FIGURE 21: DETAILED DRAWING OF THE BACK MUSCLES

38

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40

representative muscle cross section shapes to fit JOHN SD. The shapes were
then scaled directly from the plots and used to make profiles. These profiles
were then generated with the Construction Geometry section of the IDEAS [13]
software. Again, each of the profiles was created separately, using the X and Y
axis coordinates, then positioned along the Z axis at the location they were
generated from the plots. Once the profiles were in position, a surface was
generated over each profile to make a solid object. Figure 24 illustrates the
thoracic erecfor spinae muscle group and the lumbar erector spinae muscle
group.

A different method was used to model the obliquus abdominis muscles on
the sides of the torso between the rib cage and pelvis; this method might be
called ”String Art" and has been used by Dostal et al. [20] to connect the origin
and insertion points of hip musculature with string. This approach was taken
because the obliquus abdominis muscles have a very small cross section and
would be hard to develop as section profiles. The obliquus abdominis muscles
connect the pelvis to the rib cage which move relative to each other. The
muscles lengthen and shorten with this movement. The location of the origin and
insertion points for the obliquus abdominis muscles was based on Stone and
Stone [19], who give a detailed description of these locations. Figure 25 is an
illustration of the obliquus abdominis taken from Stone and Stone [19]. To
represent the obliquus abdominis muscle origin and insertion points on JOHN 3-
D, the points were created by using the Auxiliary Geometry attributes of the
IDEAS [16] software, and each point was represented as a node. Next, straight
lines were generated between each of the nodes; these lines represent the
muscles in the ”String Art” approach. Each node was created as part of the
object on which it lies, then, as the object moves, the node moves with it. Figure

26 shows the computer model (JOHN 3-D) with muscles.

41

 

a) side View

Thoracic

b) back View — I I_’

A“
~—

 

 

/

Thoracic
Lumbar

 

 

 

 

 

 

 

l Lumbar

 

 

FIGURE 24: THE ERECTOR SPINAE MUSCLES a) side view D) back view

42

OBLIOUUS EXTERNUS ABDOMINIS

OBLIOUUS INTERNUS ABDOMINIS

 

Trunk—lateral view

 

Trunk—lateral View

FIGURE 25: THE OBLIOUUS ABDOMINIS MUSCLES

43

side View

 

back View

Ev...

 

 

 

 

FIGURE 26: JOHN 3-D WITH MUSCLES REPRESENTED

44

3.2.4 Motion Program

Haas [5] developed the vertebral articulation and constructed a program
that represents this motion for the JOHN 2-D model. A similar program located in
Appendix A was generated for the JOHN 3-D model. This program uses the
approach from Haas and then adds some further body movement. One addition
was the pivoting of the torso about the ischial tuberosities to locate the Torso
Recline Angle (TRA). Another task of the program was to move the muscles.
The program starts by asking the user to input their desired Total Lumbar
Curvature (TLC), Torso Recline Angle (TRA) and Head Rotation Angle (HRA).
Starting with a straight lumbar spine (ie. TLC equal to 0° ), the first step for the
program was to locate the head. The head was rotated equally about each of the
cervical joint centers starting at the top and moving down. The head is rotated
with respect to the eye-line; for an HRA of 0°, the eye-line is horizontal. The
program calculates the amount of rotation needed to hold the eye-line level,
given the values of TLC and TRA, and then rotates the amount input for HRA.
The program rotates about the cervical joint centers which are positioned above
and below each vertebrae. There are eight joint centers in the cervical spine,
therefore, the amount rotation for each vertebrae was equal to 1/8 the value input
for TLC, starting at TLC equal to 0°, minus the amount of rotation that was
needed to locate the body into the TRA position, starting with TRA equal to 35°,
the HRA was then added. The lumbar articulation was performed by rotating
about each of the six lumbar joint centers, an amount equal to 1/6 the value input
for TLC. When the program rotates about a joint center it rotates each
component located above that joint. The locations of each of the vertebral joint
centers in three-dimensional space for the initial position of TLC equal to 0° have
been added in Appendix B. These positions are used in the program. Once the

cervical and lumbar spines were articulated, then the model was rotated about

45

the ischial tuberosities to position the torso in the position as defined by the TRA.
The last process of the program was made to relocate the muscles according to

the articulated skeletal position. The arms and legs have not been examined for
this study, therefore, the program simply locates them in their original orientation.

Figure 27 represents the three-dimensional motion of the model.

3.2.5 Generating Skin

The back surface of JOHN SD was created by adding a skin layer over
the skeleton and muscles. This process began by generating horizontal cross
section plots of the torso from the JOHN 3-D computer model. Figure 28 shows
the torso of JOHN 3-D and the location of the cross sections. The plots were
examined and compared to Koritke and Sick [17] to determine a representative
skin thickness. On each of the plots, a surface was hand drawn which was
directly contoured to the bones and muscles; this surface represented the skin.
Once the surface was hand drawn, points were measured at consistent positions
along the Y axis on the plot. These points were then input to the computer using
the Construction Geometry task of the IDEAS [16] software and cubic splines
were generated through each point to make a mesh of curves. This mesh of
curves is represented in Figure 29. Then, by going into the Object Modeling task,
a skin was created from the mesh of curves. The same process was then used
to generate skin on the model at positions for TLC ranging from -10° to 40°, in
increments of 10°. Tables 1-6 in Appendix C indicate the points used to skin the
model. Figures 30 through 35 illustrate the model skinned for the different TLC
postures with TRA and HRA equal to 0° in each figure. Cross sectional plots
were made along the torso perpendicular to the TRA and are represented in
Appendix D.

46

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48

 

 

 

a) side We)” b) back View

 

 

 

 

 

 

 

 

/ / c) oblique view

 

 

 

 

FIGURE 29: MESH OF CURVES FOR BACK SKIN

49

 

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52

  

 

 

 

   

 

 

 

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55

3.3 Results and Discussion

3.3.1 Comparing JOHN 3-D with the UM-TRI Study

UM-TRi [3] developed a three-dimensional body form that represents the
ﬁftieth percentile adult male in a single posture which has been adopted for
JOHN 2-D and JOHN 3-D with TLC=0°. The UM-TRl body form was created by
the collection of data taken in 3-D space on human subjects. These subjects
were selected to match the fiftieth percentile human stature. They were tested in
a laboratory while sitting in automotive seats. JOHN 3-D skeleton was
developed with the use of the UM-TRI [3] study but the skin on JOHN 3-D was
created independent of the UM-TRI study. A comparison was made by
examining the horizontal cross sections of each model. The UM-TRI body form
was digitized by the Advanced Design Staff at General Motors, then a 3-D
computer model was made of the body surface. Figure 36 represents a side
View of the UM-TRI model and the JOHN 3-D model. Horizontal sections, on the
UM-TRI model, were made at vertical levels of 0, 100, 200, 300 and 400 mm
from an origin at the Hip Joint Center as described by UM-TRl. JOHN 3-D has a
different Hip Joint Center location than UM-TRI which is 25mm below the UM-TRI
HJC location in the vertical direction with a posture at TLC equal to 0°. This
difference in position was due to Has [5] who concluded that the lumbar spine
length was longer than represented by UM-TRI [3]. The coordinate system for
JOHN 3-D originates at the Hip Joint Center, therefore, for accurate comparison
the horizontal sections made on JOHN 3-D were taken at 25, 125, 225, 325 and
425mm above the HJC. Cross section plots (Figures 37 through 41) were made

for each model and then overlaid for this comparison.

 

 

 

UM-TRI

FIGURE 36: SIDE VIEW JOHN 3-D vs UM-TRI BODY FORM

 

 

57

 

JOI-IN x ...(0,0)

UM-‘l'Rl ------

1/5 TRUE SIZE

“’-

FIGURE 37: CROSS SECTIONS AT 400mm

X/ (0.0)

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/./'

 

 

 

FIGURE 38: CROSS SECTIONS AT 300mm

58

 

JOHN
UM-TRI ------

1/5 TRUE SIZE

 

FIGURE 39: CROSS SECTIONS AT 200mm

 

FIGURE 40: CROSS SECTIONS AT 100mm

59

JOHN
UM-TRI ----- -

 

1/5 TRUE SIZE

 

‘
.--—------0’

FIGURE 41: CROSS SECTIONS AT 0mm

60

The comparison of JOHN 3-D and the UM-TRI [3] body form indicated
similarities in the body surface location at each section. The models resemble
the same body size and overall surface shape. The major difference was the
back surface contours; JOHN 3-D has a more contoured back, and the UM-TRI
body form has a less contoured back. One significant reason for the difference in
contour is that the UM-TRI body form is the result of the interaction between the
human body and the automotive seat. The seats used for the test were not
contoured, and the body conformed to the seat. JOHN SD was created without
the interaction of the seat, therefore, the JOHN 3-D contour has been predicted
only by the body structure and not the seat. Another possible reason for the
contrast was the body casting technique used for the UM-TRI body form. Scotch
Cast tape was placed on the seat, then the tape hardened after the subject sat in
the seat. The tape most likely bridged across the deep contours. Also, the data
taken from each subject in the UM-TRl [3] study was averaged to develop one
set of points. The process of averaging the data could have caused some of the
high contour points cancel, between each subject causing the curves to smooth
out. A fourth scenario was that human body fat has not been represented on
JOHN 3-D which could ﬂatten out some of the contours. Body fat is located
differently for each person, and to try and develop a universal location was

beyond the scope of this thesis.

4. CONCLUSION

Each of the objectives investigated forthis thesis have been
accomplished.

The JOHN 2-D template was developed to represent the two-dimensional
computer model created by Haas [5]. This template accurately locates the thorax
relative to the pelvis within 1mm, for seated postures as defined by Haas [5].
JOHN 2-D can be used to compare existing automotive seat designs with human
postures as well as develop new seat designs by studying the mobility of the
human body in the seated position.

The vertebral column and back muscles have been added to the three-
dimensional computer model (JOHN 3-D) to define the contours of the thoracic
region. A Skin was also generated on the back side of the JOHN 3-D torso. The
JOHN 3-D skin represents the back surface of an average male in a seated
posture without soft tissue deflection due to seat/body contact. This thesis
compares the JOHN 3-D skin to the UM-TRI body form [3] which represents an
average male in a seated posture with the effect of the seat on the body. JOHN
3-D compared well to the UM-TRI body form in size and overall shape, the major
difference was the back contour of each skin. JOHN 3-D has a more contoured
back than the UM-TRI body form.

A motion program was created to articulate the JOHN 3-D computer
model. This program has the user input values for Total Lumbar Curvature
(TLC), Torso Recline Angle (T RA) and Head Rotation Angle (HRA). Then the

program moves JOHN 3-D to ﬁt these input specifications. Skin was generated

61

 

62

for JOHN 3-D at six different postural positions. The positions were determined
by the value of TLC equal to -10 through 40 degrees in increments of 10
degrees.

The JOHN 2-D template, which represents the Skeletal structures of the
pelvis, thorax and skull should be further developed by representing the outer
body surface as developed for the JOHN 30 computer model in this thesis.
Further work should also be concentrated on the development of these models
for different size people.

Each of the tasks completed in this thesis, i.e., development of the
JOHN 2-D template, and the JOHN 3-D computer model with skin and body
movement, are important new biomechanical models of humans for automotive
seat design. These models represent the geometry of people in automotive
seated postures. When there is a conﬂict between the body and seat, high
pressure points develop on the body resulting in discomfort by restricting blood
flow and compressing nerves. If seats can be designed to geometrically
accommodate the contours of people as they sit in different positions, then their

seats will be more comfortable.

 

APPENDICES

0x7:xzxxxxxxxxxxxnnnmxxxxxrzxxxzxxnnnxxxxxzx-J-o-uxxxxxxxxxxxz5500000000

APPENDIX A

Motion Program

MOTION PROGRAM FOR THE 3-D JOHN MODEL

"“‘ TLC-TOTAL LUMBAR CURVATURE *"“
""*** TRA-TORSO RECLINE ANGLE *‘****
""‘** HRA-HEAD ROTATION ANGLE **‘***
/

IUO

BL

B

Q

CECHO NONE

IDECLARE TLCIll

IDECLARE TRA(1)

{DECLARE TRAN(1)

IDECLARE TILT(1)

IDECLARE CERV(1)

IDECLARE LUMBIll

IDECLARE HRA(1I

IINPUT"WHAT IS THE DESIRED TLC?" TLC
IINPUT"WHAT IS THE DESIRED TRA?" TRA
IINPUT"WHAT IS THE DESIRED HRA?" HRA
ILUMB"( (TLC) l6)

lMUS“(TLC/2l

lTRAN-((TLC/2l+35l

ITILT-TRAN-TRA
ICERV-((HRA+(TLC-TILT)/8l)

/

IO

---------- LEG ROTATION------------
R

I
H

K
000
0 -TILT 0

---------- ARM ROTATION------------

-235 177 413
0 TILT 0

63

x:=::x
xxxxnnnxxxxxxxwxxxxxxxxnanxxxxxxxxxxxxxxxnnoxxwxxxxxxxxzxxnnnn

.0

64.

---------- HEAD ROTATION---—-------
ROTATE ABOUT SKULL/C1

R

I

H

52

38

37

36

35

34

33

D

K

-213 0 612
0 cerv 0

ROTATE ABOUT Cl/CZ

R

I

H

52

38

37

36

35

34

33

21

D

K

-213 0 602
0 CERV 0

ROTATE ABOUT C2/C3

R

I

H

52

38

37

36

35

34

33

21

20

D

K

-207 0 586
0 CERV 0

ROTATE ABOUT C3/C4

R
I
H
52
38
37
36
35

 

xxxxxxxzxxxnnnxxxxxxxxxxxxxxxxxxxnnnxxxxxxxxxxxxxxxxxxonnzxxxxxxxx

34

33

21

20

19

D

K

-204 0 S71
0 CERV 0

ROTATE ABOUT C4/CS

-201 0 551
0 CERV 0

ROTATE ABOUT C5/C6

K
-200 O 532
0 CERV 0

ROTATE ABOUT C6/C7

R

I

H

52
38
37
36
35
34
33
21

'65

xxxxxxxzxxxxxxxxxxxxxxxxxxxznnnooxxxxxxxxxxxxxxxxzxxxxnnnxxxzxzxxx

66

~203 0 511
0 CERV 0

ROTATE ABOUT C7/C8

-210 0 493
0 CERV 0

------------ THORAX ROTATION-----------—

ROTATE ABOUT T12/L1

-194.1 0 189.2
0 -LUMB O
R

XX X
X XXXXXXXXXXXXXXXXXXXXXXXXOOOXXXXXZXZ3X7:RIXXRXXXXRRXZXXXXXXXXX'X‘X

-194.1 0 189.2
0 -LUMB 0

75

98

D

K

~194.1 0 189.2
0 -LUMB 0

ROTATE ABOUT Ll/LZ

R
I
H
52
38
37
36

-173.08 0 159.16
0 -LUMB 0
R

67

-173.08 0 159.16
0 -LUMB 0

-173.08 0 159.16
0 -LUMB 0

RO'I‘ATE ABOUT L2/L3

-152.06 0 129.12

68

71x7:XODOXXXXXXXXXZZXXXXXXXXXXXSXXXXXXXXXXXXXXXXZX

XXXREXXXXXXXXXX

XXX

-152.06 0 129.12
0 -LUMB O

R

I

H

75

88

13

89

12

98

D

K

-152.06 0 129.16
0 -LUMB 0

ROTATE ABOUT L3/L4

69

 

xzxxxxxx7:xxxxxxonnoxxzxxxwxxxxxxxxxxxxxxxxxxxxxxwxxxxxxxxxzxxxxxxx

47

D

K

-131.04 0 99.08
0 -LUMB 0

-131.04 0 99.08
0 -LUMB 0

~131.04 O 99.08
0 -LUMB 0

ROTATE ABOUT L4/L5

70

xxxxxxxnnnxxxxxxxxxxxxxxxxxxzxxxxxxxxxxxxxxxxxxxxxxxxxaxxxxxxwxxxx

- 10 0 69
0 -LUMB 0

-110 0 69
0 -LUMB 0

ROTATE ABOUT LS/Sl

R
I
H
52
38
37
36

71

SQ

xxx-xxx

XXXXTy‘x
, . xxxzrxxx
- xxxxxx
.............. ........ --..,, Xxxxxxxxxxxxxxxxxxxxxxxx
C'OI-o............. xxxxxxxx
0 O. .0 O. .0 O. l. O. O. O. O. 0. xxxxxx

72

ZZXXXXXXIXXXSKZXXXXXXXXXXXXXXXXXXXZXXXOXXXX):IOGOOXXXXWZCOOXXZXXXZXO

73

01

XUHZHS

~100 0 10
0 -mus 0

---TILT JOHNZ INTO TRA---

7c *Hw

13.69 0 -69
0 TILT 0

----- CONNECT MUSCLES-----

EAUX

ND

”D
H

XXXXXXXXRNXXXXXXXX'SXXXXXXXXIIXXXXXXXXXXXXXXXXXXXXXX'NXX?XXXXXXXXXXX

74

IZQbIZF'Ut“-UO
U H O >
C
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U‘
6.:

XXRXXXXXZXX
XXXNRKXXX?!XXXXXXXXXXZXXXXXX7:XXXXIXXXXXXXXXXXXXXXXXXXXXX

75

XXEZXXIIXXXXII
IXXXXNXXZXXXXXXXXXXXXXXXXXXXXXXXXXRXXIXXZSVWWXXRXXXX":

76

XXXXXXXXXXXXXXXXXXXXXXXXXXXIXXXXXXXXXXXXIXXXXXXXXXXXXXXXXXXXXXXXZX

77

ERZXXXX'XEXXXXXXXXWXXXXXXXXXXRxXWWXX

71"}:

XXXXZXXXXXXXIIIIXXNXXXXXXXXKI

78

U

u

'Ul"-C33Ul:DZU‘U‘IZt"UC‘
3’ D
C
X

X7”!

mxxxxzxxxxxzx
xxxxwxwx7:7:xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

53

79

WIX'XXXXZX

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’9

NINE 2‘:
XXX CXXXXEX‘XXXXXﬁXXXXXWXXXXXZ‘:“XXIXK

80

I.
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53
16
Nl)

!AUX
L
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53
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U122
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II‘ICHU ALI.
/

!DO

BL

U

/

APPENDIX B

Spine Joint Center Coordinates

For the coordinates. cp() indicates a cervical point. Each interspace is
represented by three numbers. The first number is the X coordinate. the second
number is the Y coordinate, and the third number is the Z coordinate.

ALL COORDINATES ARE IN MM

Coordinates for the C1/SKULL interspace
Cp 1 = -213
cp 2 = 0

cp 3 = 612

Coordinates tor the 01/02 interspace
cp 4 = -213

cp 5 = 0

cp 6 = 602

Coordinates for the 02/03 interspace
co 7 = -207

cp 8 = 0

cp 9 = 586

Coordinates for the 03/04 interspace

cp10=-204
cp11 =0

 

 

 

 

Op 12 = 571

000 inates for the 04/05 interspace
cp 13 = -201

CD 14 = 0

cp 15 = 551

Coo inates for the 05/06 interspace

cp16=-200
cp17=0
18=532

 

GP
Coo inates for the 06/07 interspace
op 19 = -203

cp 20 = 0

Coordinates for the 07/08 interspace
CD 22;: -210

 

cp 23 = 0
cp 24 = 493

 

81

82
For the coordinates. tp() indicates a torso point. Each interspace is represented

by three numbers. The first number is the X coordinate, the second number is
the Y coordinate, and the third number is the Z coordinate.
ALL COORDINATES ARE IN MM

Coordinates for the 07/T1 interspace
tp 1 = -210
tp2=0
t =493

oordinates for the T1fi' 2 interspace
tp4 5 = -218

tp = 0
1 =476

oordinates for the T2/T 3 interspace
tp 7 = -226
tp 8 = 0
t 9 = 459

oordinates for the T3/T 4 interspace
tp§10§= -231

 

 

 

 

 

tp 11 = O
t 12 = 440

oordinates tor the T4/T 5 interspace
tp 13 = -237
m14=0
t 15 = 421

oordinates for the T5/T 6 interspace
1p 16 = '242
tp 17= 0

18: 395

oordinates for the T6/T7 interspace
to 19 = -241
to 20: 0

21: 367
oordinates for the 17K 8 interspace
tp§22§: -238

 

tp 23 0
24 339
oordinates for the T8/T 9 interspace
1p 25 = '232
tp 26= O
27= 311
oordinates for the T9/T10 interspace
tp 28 = -225
m29=0
t 30 = 281
oordinates for the T10/T11 interspace
tp 31 = -217
m32=0
t 33 = 251
oordinates for the T11/T12 interspace
tp 34§= -207

 

m35=0
to 36 = 251

 

83
For the coordinates, lp() indicates a lumbar point. Each interspace is

represented by three numbers. The first number is the X coordinate, the second
number is the Y coordinate, and the third number is the Z coordinate.
ALL COORDINATES ARE IN MM

Coordinates tor the T12/L1 interspace
ID 2 = O
=.189 2
loordinates for the L1/L2 interspace
lp4 = -173.7
m5=0
.-.159. 16
oordinates for the L2/L3 interspace

lp§7 : -1 52.06
8

 

 

 

= 0
129.12
oordinates tor the L3/L4 interspace
Ip310): 6131.04
I8012 99. 08
ordinates for the L4/L5 interspace
1113: 6110. .02
|8015 69.04
ordinates for the L5/S1 interspace
Ip 16 = -89
lp 18 = 39

X ~230
Y 218
Z 475

N:
o:
c:

220
450

~23O
210
400

~168
180
350

~155
170
300

~145
168
250

~130
165
200

~100
160
150

~65
155
100

-45

155
50

165

N-<>< N-(X N-(X N-<>< N-(X N-(X N-(X N-(X N-(X N-(X N-<>< N-(X N-(X N-(X

2
~275
180
475

~285
180
450

~275
175
400

~265
165
350

~255
160
300

-220
160
250

~200
158
200

~170
155
150

~120
148
100

~100
150
50

~80
155

~55
160
~20

~25
160
~25

160
~30

50
160
~30

3

~280
133
475

~290
133
450

~295
133
400

~288
133
350

~280
133
300

~260
133
250

~245
133
200

~205
133
150

~180
133
100

~150
133
50

~140
133

~80
145
~33

~50 '

145
~50

145
~65

50
145
~65

4
~283

475

~293
95
450

~305
95
400

~308
95
350
~303
95
300
~285
95
250
~263
200
~235
150
~205
95
100
~185
50
~158
95

~122
95
~52

95
~83

95
~96

50
95
~88

5
~280

475
~290
450
~300
400
~302
63
350
~297
63
300
~288
63
250
~270
200
~246
63
150
~220
100
~188
50
~158
63

-124
63
-54
~85
es
63
~96
so

~88

APPENDIX C
Table of Skin Points
Table 1 Skin Points for TLC=0:

6
~273

475
~283
450
~295
25
400
~300
350
~295
25
300
~288
25
250
~268
25
200
~245
150
~218
100
~185
25
50
~155
25

-123
25
~53

~83
25
~83

25
-94

50
25
~86

7
~278

475
~288
450
~298

O

400
~302
350
~295
300
~290
250
~273
200
~250
150
~223
100
~190
50
~150

~122
~52
~82
~82

~92
50
~85

84»

8
~273
~25
475

~283
~25
450

~295
400

~300
~25
350

~295
~25
300

~288
~25
250

~268
~25
200

~245
~25
150

~218
~25
100

~185
~25
50

~155
~25

~123
~25
~53

~83
~25
~83

-25
-94

50
~25
~86

9
~280
~63
475

~290
~63
450

~300
~63
400

~302
~63
350

~297
~63
300

~288
~63
250

~270
63
200

~246
~63
150

~220
~63
100

~188
~63
50

~158
~63

-124
-63
-54

~85
~63
~85

~63
~96

50
~63
~88

10
~283
~95
475

~293
~95
450

~305
~95
400

~308
95
350

~303
~95
300

~285
250

~263
~95
200

~235
150

~205
~95
100

~185
~95
50

~158
~95

~122
-95
~52

~83
~95
~83

~95
~96

50
~95
~88

11
~280
~133

475

~290

'~133

450

-295
:133
400

~288
~133
350

~280
~133
300

~260
~133
250

~245
~133
200

~205
~133
150

~180
~133
100

~150
~133
50

~140
~133

~80
~145
~33

~145
~50

~145
~65

so
-145
-65

12
~275
~180

475

~285
~180
450

~275
~175
400

~265
-165
350

~255
~160
300

~220
~160
250

~200
~158
200

~170
~155
150

~120
~148
100

~100
~150
50

~80
~155

~55
~160
~20

~25
~160
~25

~160
~30

50
~160
~30

13
~230
~218

475

~230
~220
450

~23O
~2|0
400

~168
~180
350

~155
~170
300

~145
~168
250

~130
~165
200

~100
~160
150

~65
~155
100

45

~155
50

-165

N-(X N-(X N-<>< N-<>< N-<>< N-(X N-(X N-<

165

-3
165

165

50
165
0

2
~260
180
475

~260
180
450

~270
175
400

~250
165
350

~228
160
300

~215
160
250

~210
158
200

~180
155
150

~143
148
100

~125
150
50

~120
155

~89
160
~30

~28
160
~30

160
~30

50
160
~30

3
~265
133
475

~275
133
450

~287
133
400

~283
133
350

~290
133
300

~269
133
250

~258
133
200

~205
133
150

~180
133
100

~158
133
50

~148
133

-118
145
-45

-47
145
-59

145
~65

50
145
~65

85

Tablwkin Points for TLC= ~10:

4
-270

475
~280
95
450
~294
400
~305
95
350
~309
95
300
~288
95
250
~275
200
~245
150
~217
95
100
~183
50
~163
95

~133
95

..-51

~58
95
~93

95
~96

50
95
~86

5
~274
63
475

~285
450
~300
63
400
~311
350
~308
300
~298
63
250
~284
63
200
~263
63
150
~229
100
~194
63
50

~167
63

~135
63
~53

~60
~95
63
~96
50

63
~85

6
~270

475
-280
450
-293
400
-307
25
350
808
25
300
-298
250
-283
zoo
~263
25
150
-230
100
-202
25
so
-167
25
-134
-52
~58

25
~93

25
-94

so
25
~84

7
~265

475
~277
450
~295
400
~305
350
~305
300
~300
250
~285
0
200
~264
150
~235
100
~203
50
~165

~132
~50
~57
~92

~92
50
~82

8
~270
~25
475

~280
~25
450

~293
~25
400

~307
~25
350

~306
~25
300
~298
~25
250

~283
~25
200

~263
~25
150
~230

~25
100

~202
~25
50

~167
~25

~134
~25
~52

~58
~25
~93

-25
-94

50
-25
~t$4

9
~274

475
-285

«Iso
-300

63
400

~311
~63
350

~308
~63
300

~298
~63
250

~284
~63
200

~263
~63
150

~229
~63
100

~194
~63
50

~167
~63

-135
~63
~53

~60
~63
~95

~63
~96

50
-63
~85

10
~270
~95
475

~280
~95
450

~294
~95
400

~305
~95
350

~309
~95
300

~288
~95
250

~275
~95
200

-245
-95
I50

~217
~95
100

~183
~95
50

~163
~95
0

~133
~95
~51

~58
~95
~93

o
-95
-96

50
~95
~86

11
~265
~133

475

'~275

~133
450

~287
~133
400

~283
-1 33
350

~290
~133
300

~269
~133
250

~258
~133
200

~205
~133
150

1180

~133
100

~158"

~133
50

~148
~133

-118
-145
'45

~47
~145
~59

~145
~65

50
~145
~65

12
~260
~180

475

~260
~180
450

~270
~175
400

~250
~165
350

~228
~160
300

~215
~160
250

~210
~158
200

~180
~155
150

~143
-148
100

~125
~150

~120
~155

~89
~160
~30

~28
~160
~30

~160
~30

50
~160
~30

13
~225
~220

475

~225
~220
450

~238
~210
400

~200
~180
350

~160
~170
300

~150
-168
250

~138
~165
200

~110
~160
150

~75
~155
100

-4o
455
so
80
-185

~15
~165

~3
~165

~165

50
~165

X ~250
'Y 220
Z 475

X ~250
Y 220
Z 450

X ~235
Y 210
Z 400

X~175
Y 180
Z 350

~125
170
300

~115
168
250

~105
165
200

~75
160
150

-4o
155
100

i~ tn 6:
01 c: u:

165

0

do
O)‘
0010

—L
OI
0010

d
0)
001°

0'1
0

165
0

hb<>< hh<>< 1V-<)< lV-(>< 1V-<>< hh<>< hb<>< lV-<>< hh<>< hh<>< hb<)<
Z5
01

2
~287
180
475

~296
180
450

~280
175
400

~275
165
350

~260
160
300

~220
160
250

~180
158
200

~165
155
150

~120
148
100

~90
150
50

~65
155

-45
160
80

~24
160
~30

160
~30

50
160
~30

3
~290
133
475

~299
133
450

~300
133
400

~300
133
350

~285
133
300

~260
133
250

~225
133
200

~200
133
150

~180
133
100

~140
133
50

~125
133

-73
145
-45

-45
145
-59

145
~65

50
145
~65

86

Table 3 Skin Points for TLC=10§

4
~293
95
475

~301
95
450
~308
95
400
~312
350
~305
300
~283
250

~250
95
200

~230
95
150
~200
100
~165
50

~143
95

~113
95
~51

~65

95
~93

95
~96
50
~86

5
~290

475

~299
63
450

~305
63
400

~310
63
350

~304
63
300
~285

63
250

~260
200
~235
150
~203
63
100
~168
63
50

~145
63

~115
63
~53

~66

63
~95

63
~96
50
~85

6
~289

475
~295
450
~300
400
~304
350
~298
25
300
~285
250

~259
25
200

~236
150
~203
100
~170
25
50

~143
25

~114
25
~52

~65
-93
25
-94
so

25
~84

64
-92

~92
50
~82

8
~289
~25
475

~295
25
450

~300
400

~304
~25
350

~298
~25
300

~285
~25
250

~259
~25
200

~236
~25
150

~203
~25
100

-170
~25
50

~143
~25

~114
~25
~52

~65
~25
~93

-2s
-94

so
25
~84

9
~290
~63
475

~299
~63
450

~305
~63
400

~310
~63
350

~304
~63
300

~285
~63
250

~260
200

~235
~63
150

~203
63
100

~168
~63
50

~145
~63

~115
~63
~53

~66
~63
~95

-63
~90

50
~63
~85

10
~293
~95
475

~301
~95
450

~308
~95
400

~312
350

~305
~95
300

~283
~95
250

~250
~95
200

~230
~95
150

~200
~95
100

~165
~95
50

~143
~95

~113
~95
~51

~65
~95
~93

-95
~96

50
~95
~86

11

~290'

~133
475

~299
~133
450

~300
~133
400

~300
~133
350

~285
~133
300

~260
~133
250

~225
~133
200

~200
~133
150

~180
~133
100

~140
~133
50

~125
~133

-73
-145
.-45

:45
-145
-59

~145
~65

50
~145
~65

12
~287
~180

475

~296
~180
450

~280
~175
400

~275
~165
350

~260
~160
300

~220
~160
250

~180
~158
200

~165
~155
150

~120
~148
100

~90
~150
50

~65
~155

-45
-160
so

-24
~160
-3o

~160
~30

50
~160
~30

13
~250
~220

475

~250
~220
450

~235
~210
400

~175
~180
350

~125
~170
300

~115
~168
250

~105
~165
200

~75
~160
150

-40
~155
100
~25
~155
50

~15
~165

~10
~165

~165
0
~165

50
~165

N-<)< N-(X N-(X N-(X N-<>< N-<>< N-<>< N-(X N-<

0

2
~305
180
475

-314
180
450

'~296

175
400

~280
165
350

~260
160
300

~230
160
250

~150
158
200

-140
155
150

~90
148
100

~70
150
50

~60
155

.42
160

~24
160
~23

160
~30

50
160
~30

3
~310
133
475

~316
133
450

~316
133
400

~310
133
350

~284
133
300

~254
133
250

~200
133
200

~180
133
150

~150
133
100

~120
133
50

~115
133

~68
145
~24

-45
145
-so

145
~65

50
145
~65

87

Table 4 Skin Points for TLC=20j

4
~314

475
~318
450

~320
95
400

~320
95
350

~304
95
300

~277
95
250

~239
95
200

~212
95
150

~178
95
100

~145
95
50

-134
95

-113
95
.40

~65
95
~83

95
~96

50
95
~86

5
~311

475
~317

450

~319
63
400
~318
63
350
~305
300
~280
250
~249
63
200
~219
150
~188
63
100
~153
50

~136
63

-115
63
-42

~66
63
~85

63
~96

50
63
~86

6
~310
25
475

~313
450
~316
400
~313
25
350
~300

25
300

~279
25
250

~248
25
200

~220
150
~188
100
~155
25
50

~135
25

~114
25
~41

~65
25
~84

25
~94

so
25
~84

7
~310

475
~315
0
450
~318
400
~315
350
~300
300
~276
250
~248
0
200
~215
150
~178
100
~145
50
~130

-1 1 1
.4o
-54
-82

~92
50
~82

8
~310
~25
475

~313
~25
450

~316
~25
400

~313
~25
350

~300

~25
300

-279
250
~248
200
-220
25
150
-188
-25
100
-155
-25
so
-135
-25
~114
~41
65

-25
~84

-25
~94

so
-25
~84

9
~311
~63
475

~317
~63
450

~319
400

~316
~63
350

~305
~63
300

~280
~63
250

~249
200
~219
150

~188
~63
100

~153
~63
50

-136
~63

-115
-63
-42

~66
~63
~85

~63
~96

50

~63
~86

10
~314
~95
475

~318
~95
450

~320
~95
400

~320
~95
350

~304
~95
300

~277
~95
250

~239
-95
200

-212 ',

150

~178
~95

100'

~145
~95
50

~134
~95

-113
-95
-40

~65
~95
~83

~95
~96

50
-95
~86

12
~305
~180

475

~314
~180
450

~296
~175
400

~280
~165
350

~260
~160
300

~230
~160
250

~150
~158
200

~140
~155
150

~90
~148
100

~70
~150
50

~60
~155

~42
~160
~8

-24
-1 so
-23

~160
~30

50
~160
~30

13
~260
~220

475

~260
~220
450

~245
~210
400

~175~
~180
350

~135
~170
300

~115
~168
250

~100
~165
200

~85
~160
150

~60

~155
100

~155

N-(X

-<><

N-(X N-(X N-(X N-(X N-<>< N-(X N<>< N-(X N-(X N-(X N-(X N-(X N-(X N

~260
218
475

~260
450

~260
210
400

~205
180
350

~150
170
300

~120
168
250

~100
165
200

~50
160
150

~10
155
100

N
N
O

155
50

10
165

~15
165

~3
165

165

50
165
0

160

50
160
~30

3
~312
133
475

~320
133
450

~318
133
400

~292
133
350

~275
133
300

~246
133
250

~200
133
200

~165
133
150

~140
133
100

~110
133
50

~102
133

~65
145
~23

-45
145
~50

145
~65

50
145
~65

88

Table 5 Skin Points forlLLC=303

4
~315

475
~323
95
450
~326
95
400
~318
350
~302
300
~268
95
250
~225
95
200
~195
95
150
~160
95
100
~135
50
~120
95

~103
95
~39

~65

95
~83

95
~96
50
~86

5
~312

475
~320
450
~323
400
~317
350
~299
63
300
~271
63
250
~235
200
~200
150
~165
100
~138
63
50
~122
63

~105
63
~40

~66
~85
63
~96
50

63
~86

6
~311

475
~315
25
450
~318
400
~313
350
~296
300
~270
250
~236
25
200
~202
25
150
~170
25
100
~140
25
50
~117
25

~104
25
~39

~65
25
~83

25
-94

so
25
~84

7
~312

475
~320
450
~320
400
~312
350
~295
300
~271
250
~235
200
~195
150
~155
100
~130
50
~112

~102
~38
~64
~82

~92
50
~82

8
~311
~25
475
~315
~25
450

~318
~25
400

~313
~25
350

~296
~25
300

~270
~25
250

~236
~25
200
~202

~25
150

~170
~25
100

~140
~25
50

~117
~25

~104
~25

~65
~25
~83

25
-94

so
-25
~84

9
~312

475
~32
-63
450

323
400
-317
350
-299

~63
300

~271
~63
250
~235

~63
200

~200
~63
150

~165
~63
100
~138
~63
50

- 122
-63
-105
-40
-66

~63
~85

~63
~96

50
~63
~86

10
~315
~95
475

~323
~95
450
~326

~95
400

~318
350

~302
~95
300
~268

~95
250

~225
~95
200

~195
~95
150

~160
~95
100

~135
~95
50

~120
~95

~103
~95
~39

~65
~95
~83

~95
~96

50
~95
~86

~133

11
~312
~133

475

~320
~133
450

~318
~133
400

~292
~133
350

~275
~133
300

~246
~133
250

~200
~133
200

~165
~133
150

~140
~133
100

~110
~133
50

~102

~65
~145
~23

-45
-145
~50

~145
~65

50
~145
~65

12
~305
~180

475

~318
~180
450

~305
~175
400

~250
~165
350

~240
~160
300

~200
~160
250

~163
~158
200

~130
~155
150

~80
~148
100

~60
~150
50

-42
-155

~38
~160
~8

-24
-180
-23

~160
~30

50
~160
~30

13
~260
~218

475

~260
~220
450

~260
~210
400

~205
~180
350

~150
~170
300

~120
~168
250

~100
~165
200

~50
~160
150

~10

~155
100

~155

1
X 600
'Y 218
.Z 475

X ~300
Y 220
Z 450

X ~290
Y 210
Z 400

X 610
Y 180
Z 350

~165
170
300

~130
168
250

~110
165
200

~75
160
150

~35
155
100

~20

155
50

165

N-(X N-(X N-(X N-<X N-<>< N-(X N-(X N-(X N-<>< N-(X N-<><

0

2
~320
180
475

~325
180
450

~315
175
400

~260
165
350

~250
160
300

~215
160
250

~175
158
200

~140
155
150

~100
148
100

~70
150
50

~60
155

~38
160
-8

-24
160
-23

160
~30

50
160
~30

3
~350
133
475

~350
133
450

~348
133
400

~330
133
350

~300
133
300

~260
133
250

~210
133
200

~175
133
150

~150
133
100

~120
133
50

~120
133

~65
145
~23

-45
145
-so

145
~65

50
145
~65

89

Table 6 Skin Points for TLO=403 ’

4
~354
95
475

~355
450
~356
95
400
~345
350
~328
300
~285
95
250
~239
200
~205
150
-165
95
100
~145
50
~134
95

.107
95
-45

~65
95
~83

95
~96

50
95
~86

5
~350

475
~350
450
~352
63
400
-343
63
350
~325
63
300
~292
250
~249
63
200
~213
63
150
~175
100
~150
63
50
~135
63

-1 12
63
-4o
~66
~85
63
~96
so

~86

6
~347

475
-347
450

~346
25
400

-340
25
350

~322
25
300

~286
25
250

~250
25
200

~215
150

~178
25
100

~152
25
50

~133
25

~109
25
~39

~65
25
~83

25
-94

so
25
~84

7
~348

475
-350
450
~348
400
-338
350
320
300
~285
250
-246
200
-205
150
~168
100
.140
so
-130

-1os
~38
-64
~82

~92
50
~82

8
~347
~25
475

-347
25
450

~346
400
~34O
350

~322
~25
300

~286
~25
250

250
~25
200

~215
~25
150

~178
~25
100

~152
~25
50

~133
~25

~109
~25
~39

~65
~25
~83

-25
-94

so
-25
-84

9
~350
~63
475

~350
~63
450

~352
~63
400

~343
~63
350

~325
~63
300

~292
~63
250

~249
200

~213
~63
150

~175
~63
100

~150
~63
50

~135
~63

-112
-63
.40

~66

~63
~85

-63
~96

50
~86

10
~354

475
355
456
~356

95
400
-345
356
628

95
300

~285
~95

250‘

~239
~95

200

~205
~95
150

-165
~95
100

~145
~95
50

~134
~95

~107
~95
~45

~65
~95
~83

~95
~96

50
~95
~86

12
~320
~180

475

~325
~180
450

~315
-175
400

~260
-165
350

~250
-160
300

~215
~160
250

~175
~158
200

-140
~155
150

~100
-148
100

~70
~150
50

~60
~155

~38
~160
-8

-24
-160
-23

~160
~30

50
~160
~30

13
~300
~218

475

~300
~220
450

~290
~210
400

~210
~180
350

~165
~170
300

~130
~168
250

—110
~165
200

~75
~160
150

~35
~155
100

~20

~155
50

~165

APPENDIX D
JOHN 3~D CROSS SECTIONS

T5

T7

   

LI

FIGURE 42: JOHN 3~D TORSO SIDE VIEW WITH SECTIONS

90

91

 

FIG -
URE 43- SECTION AT T5

 

92

 

 

 

 

FIGURE 44: SECTION AT T7

94

 

FIGURE 46: SECTION AT T1 1

95

 

FIGURE 47: SECTION AT L1

96

 

FIGURE 48: SECTION AT L2

97

 

FIGURE 49: SECTION AT L3

98

FIGURE 50: SECTION AT L4

 

 

99

 

 

 

FIGURE'S'I: SECTION AT L5

BIBLIOGRAPHY

10.

11.

12.

BIBLIOGRAPHY

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Vehicle Seating Accommodation”, S.A.E. Handbook 1980- art 2,
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Chaffin, DB. and G.B.J. Andersson, Occupationa_1_Biomechanics. John
Wiley & Sons, Inc., New York, NY, 1991.

Robbins, D.H., "Anthropometric S ecifications for the Mid-Sized Male
Dummy", UMTRI-83-53-2 .S. Department of Transportation,
Ngaggnal Highway Traffic Safety Administration, Washington, D.C.,

Synder, R.G., D.B. Chaffin and R.K. Schutz, "Link System of the Human
Torso", AMRliTR-71-88, Aerospace Medical Research Lab.,
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Haas, W.A., ”Geometric Model and Spinal Motions of the Average Male in
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Panjabi, MM. and A.A. White III, Clinical Biomechanics of the Spine, J.B.
Lippincott, Philadelphia, PA. 1978.

Allbrook, D., "Movements of the Lumbar Spinal Column”, The Journal of
Bone and Joint Surgeg, Vol. 398, No 2, pp 339-345, 1957.

Boughner, R.L, "A Model of Average Adult Male Human Skeletal and Leg
Muscle Geometry and Hamstring Length for Automotive Seat
Designers", Masters Thesis, Michigan State University, 1991.

Clemente, C.D., Anatomy - a Regional Atlas of the Human Body, Urban &
Schwarzenberg, 1981.

Hollinshead, W.H. and C. Rosse, Textbook of Anatomy, 4th Edition,
Harper and Row, 1985.

Peck, S.R. Atlas of Human Anatomy fgr the Art_is_t,, Oxford University
Press, New York, NY. 1951.

Robbins, DH. and HM. Reynolds, ”Position and Mobility of Skeletal
Landmarks of the 50th Percentile Male in an Automotive Seating
Posture”, UM-HSRl-Bl-74-4 Vehicle Research Institute, Society of
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100

13.

14.

15.

16.

17.

18.

19.

20.

101

Nyquist, CW. and L.M. Patrick, ”Lumbar and Pelvic Orientations of the
Vehicle Seated Volunteer", Twentieth Stapg Car Crash Confere_n_c_e_,
Report Num. 760821, pp. 665-696, 1976.

Andersson, G.B.J., R.W. Murphy, R. Ortengren and A.L. Nachemson,
”The Inﬂuence of Backrest Inclination and Lumbar Support on
Lumbar Lordosis”, Spine, Vol. 4, No. 1, pp. 52-58, 1979.

Hubbard, RP. and 0.6. McLeod. "A Basis for Crash Dummy Skull and
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SDRC IDEAS 4.0 Solid Modeling Package, Structural Dynamics Research
Corporation, Milford, Ohio, 1991.

Koritka, J.C., and H. Sick, Atlas of Sectional Human Anatomy, Urban &
Schwarzenberg, Baltimore, Md. 1983, Plates HT-1 through HT-15.

Netter, R.J., Atlas of Human Anatomy, ClBA-Geigy Corporation, Summit,
New Jersey, 1989.

Stone, R.J. and J.A. Stone, Atlas of the Skeletal Muscles,Wm. C. Brown
Publishers, Dubuque, IA, 1990.

 

Dostal, WP. and JG. Andrews, ”A Three-Dimensional Biomechanical
Model of Hip Musculature", Journal of Biomechanics Vol.14, No.11,
1981. pp. 803-812.

 

"Il'lllllllllllllllllllllllll“