ANALYZING the EFFECT SERVICE VESTS HAVE on CANINE GAIT By

ANALYZING THE EFFECT SERVICE VESTS HAVE ON CANINE GAIT by

LOUISE ASHLEY

(Under the Direction of Timothy Foutz)

ABSTRACT The aims of this study were to develop a technique to measure canine truncal rotation and to compare that rotation for a dog wearing and not wearing a service vest. Five dogs of various breeds were used in the study. Kinematics data were collected for each dog as the dog walked and trotted on a treadmill thereby establishing a set of baseline parameters for each individual dog that could be compared to the dog walking on the treadmill while wearing the vest. The specific parameters quantified and analyzed in this study were thorax rotation, scapula rotation, pelvis rotation, and vest rotation, with the intent of developing a method for measuring these parameters compared to a relatively stationary coordinate system on the dog. Results indicate that there were measurable differences in canine gait for each of the two service vests compared with baseline. ANALYZING THE EFFECT SERVICE VESTS HAVE ON CANINE GAIT

LOUISE ASHLEY

B.S. Biochemical Engineering, University of Georgia, 2014

A Thesis Submitted to the Graduate Faculty of The University of Georgia in Partial Fulfillment

of the Requirements for the Degree

MASTER OF SCIENCE

LOUISE ASHLEY

Major Professor: Timothy Foutz Committee: Eric Freeman Steve Budsberg

Electronic Version Approved:

Suzanne Barbour Dean of the Graduate School The University of Georgia August 2017 TABLE OF CONTENTS

LIST OF FIGURES ...... v LIST OF TABLES ...... vi CHAPTER 1: INTRODUCTION/LITERATURE REVIEW ...... 1

1.1 USING KINEMATICS TO ANALYZE CANINE GAIT ...... 1 1.2 USING RIGID BODY MECHANICS TO VALIDATE MARKING SYSTEM ...... 2 CHAPTER 2: METHOD ESTABLISHMENT ...... 5

2.1 INTRODUCTION/ABSTRACT ...... 5 2.2 GOALS OF THE FIRST STUDY AND HYPOTHESES ...... 6 2.3 MATERIALS AND METHODS ...... 8 2.4 RESULTS ...... 15 2.5 DISCUSSION ...... 20 CHAPTER 3: EFFECT VESTS HAVE ON BASELINE DATA ...... 22

3.1 INTRODUCTION/ABSTRACT ...... 22 3.2 MATERIALS AND METHODS ...... 22 3.3 WALK RESULTS ...... 29 3.4 TROT RESULTS ...... 32 3.5 DISCUSSION ...... 35 CHAPTER 4: CONCLUSIONS AND FUTURE WORK ...... 38

4.1 STUDY LIMITATIONS ...... 38 4.2 RECOMMENDATIONS FOR FUTURE WORK ...... 39 4.3 CONCLUSIONS ...... 40 REFERENCES ...... 41 APPENDICES ...... 43

iv LIST OF FIGURES

Figure 1 No vest marker placement ...... 9

Figure 2 Vest marker placement ...... 11

Figure 3 Trunk anatomical axis coordinates ...... 13

Figure 4 No vest trunk walk and trot waveform ...... 19

Figure 5 Image of dog marked without vest, with adjustable vest, with custom vest ...... 24

Figure 6 Pelvis coordinate axis ...... 27

Figure 7 Left Scapula coordinate system definition ...... 27

Figure 8 Left scapula coordinate system definition ...... 27

Figure 9 Pelvis ROM data all vests walk ...... 29

Figure 10 Left scapula ROM all vests walk ...... 30

Figure 11 Right Scapula ROM all vests walk ...... 30

Figure 12 Trunk ROM all vests walk ...... 31

Figure 13 Vest ROM all vests walk ...... 31

Figure 14 Pelvis ROM all vests trot ...... 32

Figure 15 Left scapula ROM all vests trot ...... 33

Figure 16 Right scapula ROM all vests trot ...... 33

Figure 17 Trunk ROM all vests trot ...... 34

Figure 18 Vest ROM all vests trot ...... 34

v LIST OF TABLES

Table 1 Vest rigidity table...... 16

Table 2 Dog reference axis rigidity table ...... 17

Table 3 No vest trunk ROM and standard deviation for all dogs all days ...... 18

Table 4 Statistics for interday no vest trunk data ...... 20

vi CHAPTER 1: INTRODUCTION/LITERATURE REVIEW

The military and law enforcement agencies use canines for many operations. The need for the

canines to perform at their peak level is as necessary as it is for a human. Certain duties

performed by canines often require them to wear service vests. These vests can serve many

purposes including carrying equipment, protecting the dog and functioning as a harness for

lifting the dog into a helicopter, just to name a few. While these vests have been successfully

used over the years, there is limited research on how the designs of these vests affect the dog’s

natural gait. Currently, military and police dogs use expensive custom vests which are fitted to a

specific dog and are no longer used after the dog is no longer in service. Having the opportunity

to design vests that are adjustable and that would fit multiple dogs could potentially be a cost- effective alternative to the current situation.

The purposes of the study herein are to establish a method for measuring truncal motion and to use the method to analyze the impact that service vests have on that motion. This study is part of an overall project to assess how service vests affect canine kinematics. Additionally, this study can be expanded to test various canine vest designs and materials on dogs performing various activities. The goal of this portion of the study is to validate a new marker system for measuring full truncal motion by proving the chosen markers move minimally in relation to one another and act as a rigid body.

1.1 USING KINEMATICS TO ANALYZE CANINE GAIT

The use of kinematics to analyze gait patterns is an accepted method to assess both humans and animal biomechanical function1-8. Using reflective markers on anatomical landmarks, researchers

track the positions, velocities, and rotations of rigid bodies in space. Tracking these landmarks allows researchers to characterize normal gait patterns as well as identify abnormalities in gait patterns. Many studies have been performed to establish three-dimensional models of canines that have provided joint angular motion, velocity, and acceleration, as well as stride length, stance times, and swing times in canines with and without musculoskeletal conditions4, 8, 9. This

research has shown that the use of kinematics is a valid method for objectively measuring

asymmetry and lameness in canines. Unfortunately, limited research has been conducted to

assess the kinematics of the entire canine trunk.

Kinematics, the study of the motion of an object, is very useful for measuring differences in the

motion of human and animal joints. Unfortunately, kinematic analysis of a single segment or

body part on the dog is an extremely difficult task since the dog’s position in the global

coordinate system cannot be controlled, resulting in inaccurate measurements of motion. The

motion of a body segment or a limb must instead be measured relative to a coordinate system

that is established on the dog, called a local coordinate system. Traditionally, joint motion can

be measured because it is defined as the motion of one segment relative to a linked segment.

Using kinematics to quantify the motion of the canine trunk is more difficult because a linked

second body segment is almost nonexistant and/or the two body segments do not move relative

to each other. The first portion of this overall project proposes an approach to establish the

logical location for a second body segment that allows the kinematic assessment of the canine

trunk.

1.2 USING RIGID BODY MECHANICS TO VALIDATE MARKING SYSTEM

Marker placement, skin movement and soft tissue movement are often blamed for inaccuracies in

marker measurement, which can often lead to false data. Many studies have shown the effects

these problems can have on joint angle calculations and have attempted to validate different

marker sets to address these potential causes of error10, 11. In general, canine studies which have analyzed marker variability and reliability of marker sets specifically focus on the effect these errors have on the resulting angle calculations2, 8, 10, 12. There are, however, some studies that base marker validity on the distance between two markers on a given segment13, 14. Because there

is no existing research on truncal rotation being measured in this manner, this study will use rigid

body mechanics to verify the marker sets.

For a body or segment to be considered “rigid”, the distance between any two points on the

segment must be constant. Thus the distance between any markers considered “rigid” should also

remain constant. An approach for validating a set of markers on a rigid body would be to

measure the distance between the markers and verify that this distance remains constant. Some

changes in this distance are expected since skin artifact will play a role; however, the literature

does not define an exact number for what could be considered an acceptable amount of marker

movement. For this reason, this study will use the pelvis markers as an example of “rigid” markers since the pelvis marker system is an accepted set of markers that is well published (e.g.

Torres, B.T., et al., 2017).

To minimize soft tissue artifact, the practice of clustering markers has become a popular

alternative to the traditional marker system. Clusters differ from traditional markers in that

markers are connected using a rigid plate or wire and then are attached to the segment being

investigated. Compared to traditional methods, clusters have shown to minimize skin movement reducing errors in joint calculations in both human and canine kinematic studies2, 15, 16. The study

herein also used marker clusters to create more consistent marking when 3 anatomical locations

were not available. In this situation, three markers were rigidly fixed relative to each other. Two

of these markers were placed on anatomical locations and the third marker was considered anatomical since it was in the fixed position defined by the cluster. Clusters were used in this study to minimize the impact of skin movement and to help to mark the dog consistently, particularly in situations where it was difficult to locate three anatomical locations on the scapula.

CHAPTER 2: METHOD ESTABLISHMENT

2.1 INTRODUCTION/ABSTRACT

The goal of this portion of this study is to quantify the motion of the trunk during a gait cycle and

to establish repeatability in the measurements over multiple days of collection, in order to

establish a set of baseline parameters against which the use of the intervention (wearing different

vest types) can be compared. Quantifying the movement of different canine body segments (e.g.

trunk, pelvis) must be accomplished if the impact that service vests have on the dog kinematics is

to be determined. Each segment plus the vest must be analyzed individually to quantify the

motion of the vest relative to the canine trunk. A study reported in the literature followed a

similar idea to analyze the efficacy of a canine brace. Results showed that the joint motion under

the brace is equivalent in a dog wearing the brace and not wearing a brace17. However, the study

herein is measuring the movement of a body segment which does not have an obvious second

segment for defining the local reference coordinate system needed in kinematic motion analysis.

Researchers have quantified truncal motion by tracking the spine directly;that approach proved

to be effective at measuring motion between different points along the entire backline of the

dog18, 19. The data in these studies are not useful in this study because the thorax markers along

the spine are analyzed as a rigid segment, and rotation of the thorax itself is not considered18, 19.

Rotation of the entire thorax, as opposed to just the spine, is crucial in this study because it is essential for comparing trunk rotation to vest rotation.

2.2 GOALS OF THE FIRST STUDY AND HYPOTHESES

This first study was split into three major parts in an effort to achieve the overall intent of establishing a method for measuring truncal rotation and vest rotation. The first goal of the study is to prove that the vest alone acts as a rigid body. The second goal is to locate the most rigid segment on the dog to the trunk in order to measure relative motion. The final goal is to validate

the marker system by showing consistent data across three different days within multiple dogs.

The hypotheses for each of these goals were as follows:

• Goal 1: To investigate if the service vests act as a rigid body when worn by a dog

walking on a treadmill and trotting on a treadmill. The hypothesis for this investigation

is:

o Hypothesis 1. The distance between three points on the service vest will remain the same during multiple gait cycles as a dog walks (and then trots) on a

treadmill.

. Note: Two types of service vests will be used in this investigation and it is

anticipated that both vests will act as a rigid body.

• Goal 2: To investigate which markers should be used to create a rigid reference

coordinate system for measuring relative motion of the canine trunk during gait. The

hypotheses for this investigation are:

o Hypothesis 2a. The position of the left iliac crest relative to two points (T-1, T-13) on the trunk body segment will not remain consistent as a dog walks (and trots)

on a treadmill.

o Hypothesis 2b. The position of the right iliac crest relative to two points (T-1, T- 13) on the trunk body segment will not remain consistent as a dog walks (and

trots) on a treadmill.

o Hypothesis 2c. The position of the left dorsal scapula relative to two points (T-1, T-13) on the trunk body segment will remain consistent as a dog walks (and trots)

on a treadmill.

o Hypothesis 2d. The position of the right dorsal scapula relative to two points (T- 1, T-13) on the trunk body segment will remain consistent as a dog walks (and

trots) on a treadmill.

. Note: The same two types of service vest will be used in this investigation.

It is anticipated that the dorsal scapula will provide the most consistent

results. Kinematic rotation of different body segments (e.g. trunk) will be

quantified and assessed using statistical analysis.

• Goal 3: to quantify the rotation of the canine trunk over three days and show that the

measurements are consistent. The dog will walk and then trot on a treadmill for multiple

gait cycles during three separate days. The hypothesis for this investigation is:

o Hypothesis 3. The rotation of the canine trunk will remain the same as a dog walks (and trots) on a treadmill on different days.

. Note: Trunk rotation will be quantified using the markers identified as

most rigid from goal two to create a reference system for measuring

relative motion.

7 2.3 MATERIALS AND METHODS

This portion of the study will use the following materials and methods. The first experiment will

investigate if the vest can be considered rigid during canine gait (Goal 1), the most logical

marker system for creating a local coordinate system (Goal 2), and determine if trunk rotation is

consistent when the dogs undergo gait analysis on different days (Goal 3).

2.3.1 Experimental setup

Five client-owned, adult mixed-breed dogs (weighing 20-30 kg) with no apparent lameness or

injuries were used in this study. The sample size was selected based on availability, as each dog required a custom vest. The same person made the measurements used to fabricate the custom

vest for each dog. Custom vests were fabricated by a third party (Eagle Industries), based on the

measurements made by the same investigator for all dogs using a sizing vest provided by the

third party (Eagle Industries). All of the measurements were sent to the third party (Eagle

Industries) to be fabricated. The adjustable vest was provided by this same third party. The person who made measurements for the custom vest also fitted the adjustable vest (e.g. adjusted

vest size) for each dog, after which no further adjustments were made to the adjustable vest in

between days for a given dog’s collection time. Each dog came into the lab a minimum of 3

different days for treadmill training and acclimation to the vests before the study. Every dog

acclimates differently to a treadmill, therefore some of the study dogs came in for additional

training sessions until they were comfortable on the treadmill and in the vests.

2.3.2 Data Collection

A minimum of three, fifteen-second trials of data were collected for each dog at each type of gait

(walk and trot) under three conditions; wearing a custom vest, wearing an adjustable vest, and wearing no vest. The custom vest was recorded first, followed by no vest, and then the adjustable

8 vest. This order was chosen based on the marker placement required for the different vests.

Further details of the protocol are found in Appendix B. These fifteen-second trials equate to approximately 40 walk gait cycles and 60 trot gait cycles. While canine kinematic studies do not have a specific gait cycle requirement, human kinematic studies consider 40-60 gait cycles a

significant amount of data20. This was the goal during collection as there was an expectation that

marker loss would likely occur and multiple cycles would have to be thrown out. After

processing the kinematic data and removing gait cycles that contained marker loss errors, one

session of usable kinematic data represented at least 11 gait cycles at the walking pace and at

least 18 gait cycles at the trotting pace. These numbers of gait cycles are no less than the number

of gait cycles previously reported in both human and canine kinematic studies21-25 The use of the treadmill enabled the collection of multiple cycles of a consistent, reliable gait22, 23.

2.3.3 Marker Placement

This study used 27 retro-reflective markers ranging in width and height from 1 – 2 cm (Appendix

A). The anatomical location of these markers are shown in Figure 1A and the location of each of

the tracking markers are shown in Figure 1B. The marker labeled as T-1 marker is located at the base of the dog’s neck where a significant amount of skin motion occurs. Because of the potential for variability from issues such as skin motion, all of the thorax anatomical markers designated as T-1, T-13 and Xiphoid were treated as virtual markers and tracked by markers designated as R-1, R-2, L-1 and L-2. The virtual marker system is an established method to track markers that can be hard for cameras to see, as well as locations where a significant amount of soft tissue motion may exist30.

Figure 1: No vest marker placement Figure 1A: Anatomical marker placement diagram

Figure 1B: Tracking marker placement diagram

10 2.3.4 Swing/ stance calculation

No dominant definition for the stance and swing phase using kinematic data was found in the literature. Previous studies have used the vertical spatial coordinates to measure foot fall, but this

can be difficult as the toe is still lowering throughout the stance phase12, 17. The use of a treadmill potentially magnifies this difficulty. This study defined the start of the stance phase as the furthest reach of the right toe. The end of the stance and start of the swing phase is defined as the point at which the toe changes direction. This definition resulted in the walk stance phase spanning from 0% – 70% of the gait cycle followed by the swing from70%-100%. The trot stance phase spanned from 0% – 60% of the gait cycle followed by the stance 60% - 100%.

These definitions are comparable to the literature swing/stance time26.

2.3.5 Calculations

Hypothesis 1, the distance between three points on the service vest will remain the same during

multiple gait cycles as a dog walks (and then trots) on a treadmill, was investigated as follows.

Approximately 3000 frames of kinematic data were collected while the dog walked and later

trotted on the treadmill. Markers located on the vest established a set of vectors between 1) the

T-1 and T-13 vest markers, 2) the T-1 and xiphoid vest markers, and 3) the T-13 vest and

Xiphoid vest markers (Figure 2). The magnitude of a vector from the right ischial to left ischial,

referred to herein as the pelvis vector, was also calculated to serve as a “rigid” reference. This

pelvis vector is shown in figure 1A.

Hypotheses 2a, 2b, 2c and 2d, were developed to investigate which markers should be used to

create a rigid reference coordinate system for measuring relative motion of the canine trunk

during gait. This rigid connection would allow the motion of the trunk to be assessed. The

rigidity of the T-1 marker and the T-13 marker to the dorsal scapula markers was determined by

Figure 2 Vest marker placement

Figure 2A: Marker locations for markers on Figure 2B: Marker locations for markers on the the adjustable vest custom vest taking the magnitude of the respective vectors. Similarly, the rigidity of the T-1 marker and the

T-13 marker to the iliac crest markers was also determined by taking the magnitude of the respective vectors.

Hypothesis 3 investigated if the rotation of the canine trunk remained the same when the dog walked (or trotted) on the treadmill on three different days, thereby showing consistency in the kinematic assessment. During this portion of the study the dog was not wearing a vest. The dorsal scapula marker data was combined with the T-1 and T-13 marker data to establish the

“dog reference coordinate system”. This wasused as the local coordinate system on the dog for measuring relative motion. Based on the marker placement described earlier in section 2.3.3

Marker Placement and shown in Figure 1, trunk rotation for each frame was calculated using coordinate systems for each respective segment. A coordinate system was established by defining an initial axis first and then locating a temporary axis that defined a plane between the initial axis and the temporary axis. The third axis was found by taking the cross product of the

initial defined axis as a unit vector and the temporary axis as a unit vector. In order to create an

orthogonal coordinate system, the temporary axis was redefined by taking the cross product of

the initial defined axis and the third axis. For all cross products, the right-hand rule was used.

Each axis was defined as follows, where each vector in the following equations represents the 3D coordinates of the designated marker. These marker locations are shown in figures 1A and 1B.

Dog Reference axis Coordinate system

𝑍𝑍⃑ 𝑉𝑉�⃑𝑅𝑅𝑅𝑅𝑅𝑅ℎ𝑡𝑡 𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷 𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆 − �𝑉𝑉��⃑𝐿𝐿𝐿𝐿𝐿𝐿𝐿𝐿 𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷 𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆+ 𝑉𝑉��⃑𝑅𝑅𝑅𝑅𝑅𝑅 ℎ𝑡𝑡 𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷 𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆� 2 Figure = 3 Trunk

𝑋𝑋⃑𝑇𝑇𝑇𝑇𝑇𝑇= 𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇 𝑇𝑇 𝑉𝑉�⃑𝑇𝑇−1 − 𝑉𝑉�⃑ 𝑇𝑇−13

𝑌𝑌�⃑ = 𝑍𝑍⃑ 𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐 𝑋𝑋 �𝑇𝑇𝑇𝑇𝑇𝑇 𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇

𝑋𝑋⃑ 𝑌𝑌�⃑ 𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑠𝑠 𝑍𝑍̂ Anatomical Thorax axis Coordinate system

𝑋𝑋⃑ 𝑉𝑉�⃑𝑇𝑇−1 − =𝑉𝑉� ⃑ 𝑇𝑇−13

𝑌𝑌�⃑𝑇𝑇𝑇𝑇𝑇𝑇= 𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇 𝑇𝑇 𝑉𝑉�⃑𝑇𝑇−1 − 𝑉𝑉�⃑𝑋𝑋 𝑋𝑋𝑆𝑆ℎ𝑜𝑜𝑅𝑅𝑜𝑜

𝑍𝑍⃑ = 𝑋𝑋⃑ 𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐 𝑌𝑌�⃑𝑇𝑇𝑇𝑇𝑇𝑇 𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇

𝑌𝑌�⃑ 𝑍𝑍⃑ 𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐 𝑋𝑋�

Figure 3: Anatomical thorax coordinate system marked and labeled on a dog, to show the orientation of each axis as well as the direction of rotation about each axis. Origin at T-13.

13 Using the above axis definitions, the rotation of the trunk relative to the “dog reference axis” was determined for each frame of data using Euler rotation matrices31. The frames were then split into gait cycles using cycle frame data calculated as described in the swing/stance section

(Section 2.3.4). The range of motion (ROM), defined as the difference between the minimum angles of rotation from the maximum angles of rotation, was collected for each gait cycle. These data were reduced to a single measurement by averaging the ROM over the multiple gait cycles in a given day. That is, the average ROM for each time a single dog walked on the treadmill was calculated for each dog on each of the three days that the dog was on the treadmill. In addition to

ROM, waveforms were calculated by finding the frame number for each percentage of cycle and plotting the rotation angle for that frame. To calculate wave forms, each percentage point for each cycle was averaged over 11 walk cycles and 18 trot cycles for each dog each day. The waveform for each dog each day was then used to create 95% confidence interval plots for all dogs all of the days combined (each dog has 3 samples making a total number of samples 12 or

15).

2.3.6 Analysis approach

Segment rigidity (Hypotheses 1 and 2) was analyzed by quantifying the rotation movement of the trunk segment relative to another marker system. The variability of the kinematic data over

2000 frames was used to assess rigidity. Standard deviation is a common statistical means to quantify variability and therefore was used here to explain how tightly the data from each gait cycle are clustered about the mean of the data, defining the rigidity of the segment.

Hypothesis 3 was designed to investigate the consistency of the kinematics data as those data were collected on three separate occasions/days. This variable was assessed using the ROM of truncal rotation during gait relative to the “dog reference axis coordinate system”. The ROM

14 about the x-axis, the y-axis and the z-axis of the different reference systems was determined and

a repeated measure ANOVA 31 was used to analyze this ROM data with significance differences

defined as p<=.05. When conditions violated Mauchly's Test of Sphericity, the Greenhouse-

Geisser correction was used in this analysis31.

2.4 RESULTS

The following sections provide the results used to test each hypothesis and to validate a method

for measuring truncal rotation. The following tables and figures provide examples of the results.

More extensive information can be found in the appendices.

2.4.1 Results: Vest rigidity validation

Table 1 shows the results from the analysis to prove the vest alone acts as a rigid body. As shown, the standard deviations of the vector, as defined by the ischial markers (i.e. the pelvis), were equivalent to the standard deviations of the vector defined by the vest markers. Therefore, the vest may be considered a rigid body, and the assumption has been validated that the distance between three points on the service vest will remain the same during multiple gait cycles as a dog walks (and then trots) on a treadmill.

Table 1 Vest rigidity table

15 Table 1: Average vest vector and pelvis vector magnitudes (meters) and standard deviations (meters) at the walk and trot over 3000 frames on one day.

WALK

VEST AVERAGE VEST STANDARD DEVIATION PELVIS PELVIS AVERAGE STANDARD DEVIATION

T-1 TO T-1 TO T-13 TO T-1 TO T-1 TO T-13 TO RT ISCHIAL TO RT ISCHIAL TO T-13 XIPHOID XIPHOID T-13 XIPHOID XIPHOID LT ISCHIAL LT ISCHIAL

ADJUSTABLE 0.2527 0.3147 0.3376 0.0007 0.0013 0.0009 0.1222 0.0015

CUSTOM 0.1836 0.2809 0.3001 0.0005 0.0008 0.0013 0.1155 0.0014

TROT

VEST AVERAGE VEST STANDARD DEVIATION PELVIS PELVIS AVERAGE STANDARD DEVIATION

T-1 TO T-1 TO T-13 TO T-1 TO T-1 TO T-13 TO RT ISCHIAL TO RT ISCHIAL TO T-13 XIPHOID XIPHOID T-13 XIPHOID XIPHOID LT ISCHIAL LT ISCHIAL

ADJUSTABLE .2783 .3129 .3650 .0026 .0012 .0017 .1114 .0068

CUSTOM .1715 .2867 .3126 .0005 .0007 .0028 0.1015 .0069

2.4.2 Results: Determining appropriate markers for reference coordinate system

Hypotheses 2 were focused at identifying a set of markers that remained rigid relative to the canine trunk leading to the approach for quantifying the rotation of the trunk during gait. Table 2 shows the results from one of the dogs where the rigidity between the trunk markers and the iliac crest markers, and the rigidity between the trunk markers and the dorsal scapula markers were examined. These results were obtained over 3000 frames of kinematic data, and examination of the standard deviations shows that the dorsal scapula markers provide the most rigid vectors.

Rigidity results were very similar for all of the dogs (Appendix C).

16 Table 2A: Mean and standard deviation for the pelvis vector magnitudes in meters over 2000 frames of data (10 seconds) for the walk and trot for a single dog (data for other dogs are found in Appendix C). WALK

PELVIS AVERAGE PELVIS STANDARD DEVIATION LEFT RIGHT LEFT RIGHT LEFT RIGHT LEFT RIGHT ILIAC TO ILIAC ILIAC ILIAC ILIAC ILIAC ILIAC ILIAC T-13 TO T-13 TO T-1 TO T-1 TO T-13 TO T-13 TO T-1 TO T-1

ADJUSTABLE 1 .89 .9862 .8742 .0393 .0394 .0421 .0427 NO 1.0153 .9073 .9846 .8759 .0501 .0504 .0608 .0623

CUSTOM .9798 .8724 .9902 .8820 .0388 .0406 .0427 .0442 TROT

PELVIS AVERAGE PELVIS STANDARD DEVIATION

LEFT RIGHT LEFT RIGHT LEFT RIGHT LEFT RIGHT ILIAC TO ILIAC ILIAC ILIAC ILIAC ILIAC ILIAC ILIAC T-13 TO T-13 TO T-1 TO T-1 TO T-13 TO T-13 TO T-1 TO T-1

ADJUSTABLE .9304 .8227 .9329 .8270 .0427 .0428 .0459 .0463 NO .9525 .8466 .9382 .8327 .0390 .0398 .0411 .0413 CUSTOM .8715 .7645 .8943 .7875 .0421 .0416 .0483 .0485 Table 2B: Mean and standard deviation for the dorsal scapula marker (scap) vector magnitudes in meters over 2000 frames of data (10 seconds) for the walk and trot for a single dog ( data for other dogs are found in Appendix C ). WALK

SCAPULA AVERAGE SCAPULA STANDARD DEVIATION

LEFT RIGHT LEFT RIGHT LEFT LEFT RIGHT LEFT RIGHT LEFT SCAP SCAP SCAP SCAP TO SCAP SCAP SCAP SCAP SCAP SCAP TO T- TO T- TO T- T-1 TO TO T- TO T- TO T- TO T-1 TO 13 13 1 RIGHT 13 13 1 RIGHT ADJUSTABLE .3149 .3275 .1062 .1174 .1346 .0038 .0034 .003 .0025 .0026 NO .3092 .32 .0941 .0986 .1322 .0037 .0045 .0043 .0042 .0014

CUSTOM .3274 .3379 .1104 .1211 .1305 .0031 .0035 .0037 .0033 .0010 TROT SCAPULA AVERAGE SCAPULA STANDARD DEVIATION

LEFT RIGHT LEFT RIGHT LEFT LEFT RIGHT LEFT RIGHT LEFT SCAP SCAP SCAP SCAPULA SCAP SCAP SCAP SCAP SCAP SCAP TO T- TO T- TO T- TO T-1 TO TO T- TO T- TO T- TO T-1 TO 13 13 1 RIGHT 13 13 1 RIGHT SCAP SCAP ADJUSTABLE .3164 .3256 .0980 .1021 .1216 .0047 .0059 .0042 .0043 .0043

NO .3160 .3281 .0972 .1057 .1318 .0042 .0033 .0028 .0029 .0012

CUSTOM .3301 .3356 .1115 .1214 .1314 .0025 .0022 .0034 .0016 .0012

2.4.3 Results: Method Repeatability validation

Table 3A and 3B show the average and standard deviation ROM about each axis of rotation for each dog each day at the walk and trot, respectively. The number of gait cycles used for standard deviations for each dog each day is also included in the final row. Variability in the number of gait cycles is a result of marker loss, and/or the dog breaking gait.

Table 3A: Trunk ROM average ± standard deviation in degrees for each dog each day about each axis of rotation at the walk. Number of gait cycles (GCs) used for each dog each day is also included. Walk DOG 1 DOG 2 DOG 3 DOG 4 DOG 5 DAY 1 DAY 2 DAY 3 DAY 1 DAY 2 DAY 3 DAY 1 DAY 2 DAY 3 DAY 1 DAY 2 DAY 3 DAY 1 DAY 2 DAY 3

X 13.10 14.96 18.14 14.00 18.95 16.35 7.08 7.82 7.64 18.76 24.59 13.64 9.03 ± 10.76 10.96 ± 2.02 ± 1.69 ± 1.76 ± ± ± ± ± ± ± 1.38 ± 1.51 ± 2.02 1.13 ± ± 0.746 0.695 0.953 1.22 0.981 0.799 2.37 1.16

Y 20.13 16.61 18.93 9.65 ± 10.25 9.87 ± 7.65 7.21 6.44 11.08 14.81 9.17 ± 2.92 ± 3.45 4.80 ± 1.69 ± 2.09 ± 1.7 1.28 ± 1.16 0.972 ± ± ± ± 1.48 ± 1.62 1.91 0.968 ± ± 1.91 1.18 1.24 1.17 1.15 Z 1.27 ± 2.09 ± 2.37 ± 2.03 ± 3.25 ± 1.34 ± 1.08 0.47 1.26 2.23 ± 3.37 ± 2.80 ± 0.78 ± 1.59 1.86 0.253 0.341 0.497 0.349 0.473 0.219 ± ± ± 0.34 0.485 1.06 0.193 ± ± 0.368 0.162 0.363 0.595 0.877 GC 17 25 14 28 28 28 15 15 16 26 26 19 26 25 11 Table 3B: Trunk ROM average ± standard deviation in degrees for each dog each day about each axis of rotation at the trot. Number of gait cycles (GCs) used for each dog each day is also included. Trot

DOG 1 DOG 2 DOG 3 DOG 4 DOG 5 DAY DAY DAY DAY DAY DAY DAY DAY DAY DAY DAY DAY DAY DAY DAY 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 X 21.79 19.06 17.96 20.51 22.94 20.0 17.22 15.3 12.2 13.79 18.70 16.02 7.64 7.95 7.35 ± ± 3.07 ± 2.65 ± 1.28 ± 1.55 9 ± ± 2.07 3 ± 4 ± ± 1.98 ± ± ± ± ± 2.36 1.46 2.12 1.8 2.14 1.05 1.67 0.842 1.13 Y 7.38 8.60 ± 8.44 ± 8.43 ± 8.39 ± 9.32 8.15 ± 11.2 5.30 4.73 ± 5.61 7.80 1.69 2.25 3.86 ± 1.1 0.98 0.878 0.402 1.73 ± 1.04 9 ± ± 0.811 ± 0.9 ± ± ± ± 1.45 1.25 0.88 0.59 0.55 0.458 0.685 4 6 Z 20.67 17.89 19.26 10.48 16.28 15.7 8.41 ± 8.10 6.16 15.61 18.34 16.84 9.87 9.20 9.89 ± ± 1.7 ± 1.96 ± 1.13 ± 1.81 8 ± 1.08 ± ± 1.1 ± 1.4 ± ± ± ± ± 1.72 1.37 1.13 1.39 0.968 1.37 0.682 0.958 GC 18 34 35 23 22 45 24 24 24 43 26 20 25 27 23

In addition to ROM calculations, waveforms also were made for each dog each day as previously described in the Calculations section and are shown in Figure 4.

Figure 4 No vest Figure 4: No vest trunk waveform and 95 % confidence interval at the walk (top) and trot (bottom). The solid line represents the average waveform, while the dashed line represents the 95% confidence interval for all dogs all day. Averages and confidence intervals were calculated using the average waveform for each dog each day resulting in a total sample size of 15 for both the walk and trot. The vertical axis represents rotation about each respective axis in degrees where the horizontal axis is the percentage of cycle. 0% of the gait cycle signifies the start of the swing phase (furthest reach of right toe), followed by the swing phase (Right toe changes direction) at 70% for the walk and 60% for the trot.

Waveform and 95% confidence interval calculations were made based on the minimum number

of gait cycles for each gait, meaning the walk used 11 gait cycles to calculate the 95%

confidence interval and the trot used 18 gait cycles to calculate the 95% confidence interval plot.

Table 4 is a summary of the statistical results used to investigate hypothesis 3; that is, the marker

system chosen by testing hypotheses 2 provides consistent results across three different days

within multiple dogs. These values show that day was not a significant parameter in evaluating

truncal rotation range of motion, supporting that the established marker system and method for

measuring truncal rotation can produce consistent data within a dog over multiple days. Table 2

Statistics for

Table 4: Statistics showing the impact day has on trunk ROM at the walk. Significance greater than .05 signifies that the average ROM over multiple days did not change within dog.

Mauchly's Type III Sum Mean Treatment F Sig. Test of Squares Square Sphericity Vest*day 8.340 4.170 2.296 .137 X-axis Assumed Sphericity Vest*day 1.608 .804 .382 .689 Y-axis Assumed Sphericity Vest*day .198 .099 .594 .565 Z-axis Assumed

2.5 DISCUSSION

The results support Goal 1 of this study, which was to demonstrate that the vests may be

considered as rigid bodies. Treating the vest as a rigid body allows for the measurement of vest

rotation during gait. The testing of Hypothesis 2 provided evidence that the dorsal scapula markers are more rigid to the spine markers and are therefore the more appropriate markers to

use for establishing a “dog reference axis” for describing relative motion (i.e. Goal 2).

Establishing this set of marker points allows the assessment of rotation of the dog’s trunk

without the need to assess another relative segment.

Hypothesis 3 investigated the method for measuring truncal rotation, which was shown to be

reproducible over multiple days of collection. Analyzing the data using the ROM method

supports this conclusion, as there were no significant differences in the ROM data from day to

day.

One limitation of this study was the limited number of available dogs. Use of more dogs

preferably of the same breed should be considered to validate further the use of the dorsal

scapula markers for quantifying canine truncal rotation. Because of the variability within breeds, using more dogs would be more important than using dogs of the same breed.

21 CHAPTER 3: EFFECT VESTS HAVE ON BASELINE DATA

3.1 INTRODUCTION/ABSTRACT

The goal of this portion of the study is to investigate the impact that each vest has on the dog’s

gait during walk and during trot. As mentioned previously, service vests have been successfully used over the years however, there is limited research on how the designs of these vests affect

the dog’s natural gait. Currently, military and police dogs use expensive custom vests which are

fitted to a specific dog and are no longer used after the dog is no longer in service.

The opportunity to design vests that are adjustable and that would fit multiple dogs could

potentially be a cost-effective alternative to the current situation.

This study will use both a custom and adjustable vest to see if any differences exist, as well as

differences relative to the dog’s natural gait (i.e. no vest). Each vest being investigated can be

constricting and therefore the effect of each vest on the range of motion of the dog’s gait can be

different. Using the method identified in Chapter 2, the range of motion of the rotation of the

scapula, trunk, and pelvis were measured and assessed in order to investigate differences these

vests may have on the dog’s gait.

3.2 MATERIALS AND METHODS

This portion of the study used the same set of data as provided in Chapter 2. However, different

analyses of the data were conducted to assess how the vests affect gait. The following

Experimental setup and Data Collection sections are the same sections as found in Chapter 2.

22 3.2.1 Experimental setup

Five client owned, adult mixed-breed dogs (weighing 20-30 kg) with no apparent lameness or

injuries were used in this study. The sample size was selected based on availability, as each dog required a custom vest. The same person made the measurements used to fabricate the custom vest for each dog. All of the measurements were sent to a third party (Eagle Industries) to be

fabricated. When the adjustable vest (Eagle Industries) was used, the same person made vest

size adjustments for each dog, and no further adjustments were made to the adjustable vest in between days for a given dog’s collection time. Each dog came in to the lab a minimum of 3

different days for treadmill training and acclimation to the vests before the study. Every dog

acclimates differently to a treadmill. Every dog acclimates differently to a treadmill, therefore

some of the study dogs came in for additional training sessions until they were comfortable on

the treadmill and in the vests.

3.2.2 Data Collection

A minimum of three, fifteen-second trials of data was collected for each dog at each type of gait

(walk and trot) under three conditions; wearing a custom vest, wearing an adjustable vest, and wearing no vest. The custom vest was recorded first, followed by no vest, and then the adjustable vest. Further details of the protocol are found in Appendix B. These fifteen-second trials equate

to approximately 40 walk gait cycles and 60 trot gait cycles. While canine kinematic studies do

not have a specific gait cycle requirement, human kinematic studies consider 40-60 gait cycles a

significant amount of data. This was the goal during collection as there was an expectation that

marker loss would likely occur and multiple cycles would have to be thrown out20. After processing the kinematic data and removing gait cyles that contained marker loss errors, one session of usable kinematic data represented at least 11 gait cycles at the walking pace and at

23 least 18 gait cycles at the trotting pace. These numbers of gait cycles are no less than the number of gait cycles reported in both human and canine kinematic studies21-25 The treadmill was also used in order to obtain multiple cycles of a consistent, reliable gait22, 23.

3.2.3 Marker Placement

This study used 27 retro-reflective markers ranging in width from 1 to 2 cm and height from 1 to

1.5 cm (See Appendix A for marker sizing). The location of each anatomical marker and of the tracking makers is shown in Figure 1A and Figure 1B, respectively. The virtual markers

Figu re approach was used to track markers that were difficult for cameras to detect, as well as locations where significant soft tissue motion is anticipated 30. One anatomical marker is on the spine location designated as T-1; this location is at the base of the dog’s neck where a lot of skin motion occurs (Figure 1A). Virtual markers were used as the thorax anatomical markers, located at T-1 and T-13 on the spine and at the

Xiphoid located at the underside of the dog (Figure

1A). These virtual markers were tracked by markers located at R-1, R-2, L-1, and L-2 (Figure 1B). Two sets of thorax tracking makers were used on the dog

(Figure 1B) since each vest required slight changes in Figure 5: From Top to bottom, images of a fully marked dog in the no vest the location of markers at R-1, R-2, L-1 and L-2. (top), adjustable vest (middle), and custom vest (bottom).

24 Virtual markers also provided a means to track markers on the dorsal scapula when those

markers were covered during trials involving the adjustable vest. Tracking the scapula rotation

was done by rebuilding the dorsal scapula marker location using an extra marker that is placed

on the spinal scapula shown as the spinal scapula tracking or SC-1 (Figure 1B). Figure 5 shows

the location of the markers on a dog wearing each vest and wearing no vest.

3.2.4 Swing/stance calculation

No dominant definition for the stance and swing phase using kinematic data was found in the literature. Previous studies have used the vertical spatial coordinates to measure foot fall, however this can be difficult as the toe is still lowering throughout the stance phase12, 17. The use

of a treadmill potentially magnifies this difficulty. This study defined the start of the stance phase as the furthest reach of the right toe. The end of the stance and start of the swing phase is

defined as the point at which the toe changes direction. This definition resulted in the walk

stance phase spanning from 0% – 70% of the gait cycle followed by the swing from70%-100%.

The trot stance phase spanned from 0% – 60% of the gait cycle followed by the stance 60% -

100%. These definitions are comparable to the literature swing/stance time26.

3.2.5 Calculations

Based on the marker placement described earlier in section 3.2.3 Marker Placement and shown

in Figure 2, segment rotation for each frame was calculated using coordinate systems for each

respective segment. To establish a coordinate system, an intial axis was first defined, along with

a temporary axis used to define a plane. The third axis was found by taking the cross product of

the initial defined axis as a unit vector and the temporary axis as a unit vector. In order to create

an orthogonal coordinate system, the temporary axis was redefined by taking the cross product of

the initial defined axis and the third axis. For all cross products the right hand rule was used.

25 Each axis was defined as follows, where each vector in the following equations represents the 3D coordinates of the designated marker (for marker location reference see figures 1A and 1B).

Figures 3, 6, 7, 8 show a photo of each respective segment marked with an axis system to give a visual of each coordinate system, and the axes of rotation.

Dog Reference axis Coordinate system

𝑍𝑍⃑ 𝑉𝑉�⃑𝑅𝑅𝑅𝑅𝑅𝑅ℎ𝑡𝑡 𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷 𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆 − �𝑉𝑉��⃑𝐿𝐿𝐿𝐿𝐿𝐿𝐿𝐿 𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷 𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆+ 𝑉𝑉��⃑𝑅𝑅𝑅𝑅𝑅𝑅 ℎ𝑡𝑡 𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷 𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆� = 2

𝑋𝑋⃑𝑇𝑇𝑇𝑇𝑇𝑇= 𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇 𝑇𝑇 𝑉𝑉�⃑𝑇𝑇−1 − 𝑉𝑉�⃑ 𝑇𝑇−13

𝑌𝑌�⃑ = 𝑍𝑍⃑ 𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐 𝑋𝑋�𝑇𝑇𝑇𝑇𝑇𝑇 𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇

Anatomical𝑋𝑋⃑ 𝑌𝑌�⃑ 𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐 Thorax𝑍𝑍̂ axis Coordinate Trunk Tracking Coordinate system system + + = = 2 2 �𝑉𝑉�⃑𝑅𝑅−1 𝑉𝑉�⃑𝑅𝑅−2� �𝑉𝑉�⃑𝐿𝐿−1 𝑉𝑉�⃑𝐿𝐿−2� 𝑍𝑍⃑ − 𝑋𝑋⃑ 𝑉𝑉�⃑𝑇𝑇−1 − =𝑉𝑉� ⃑ 𝑇𝑇−13 + + = 2 2 �⃑𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇 �⃑𝑇𝑇−1 �⃑𝑋𝑋 𝑖𝑖𝑆𝑆ℎ𝑜𝑜𝑅𝑅𝑜𝑜 �𝑉𝑉�⃑𝑅𝑅−1 𝑉𝑉�⃑𝐿𝐿−1� �𝑉𝑉�⃑𝑅𝑅−2 𝑉𝑉�⃑𝐿𝐿−2� 𝑌𝑌 = 𝑉𝑉 − 𝑉𝑉 ⃑𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇 𝑋𝑋 = − 𝑍𝑍⃑ = 𝑋𝑋⃑ 𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐 𝑌𝑌�⃑𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇 𝑌𝑌�⃑ = 𝑍𝑍⃑ 𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐 𝑋𝑋 �𝑇𝑇𝑇𝑇𝑇𝑇 𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇 𝑌𝑌�⃑ 𝑍𝑍⃑ 𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐 𝑋𝑋� 𝑋𝑋⃑ 𝑌𝑌�⃑ 𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐 𝑍𝑍̂

Figure 3: Anatomical thorax coordinate system marked and labeled on a dog, to show the orientation of each axis as well as the direction of rotation about each axis. Origin at T-13.

26 Left Scap Coordinate system

= ⃑ �⃑𝐿𝐿 𝑒𝑒𝑒𝑒𝑒𝑒 𝑎𝑎𝑆𝑆𝐷𝐷𝐷𝐷𝑇𝑇𝑅𝑅𝐷𝐷𝑎𝑎 �⃑𝐿𝐿 𝐿𝐿𝐿𝐿𝑡𝑡 𝑆𝑆𝑆𝑆−2 𝑋𝑋 𝑉𝑉 = − 𝑉𝑉

𝑌𝑌�⃑𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇 𝑉𝑉�⃑𝐿𝐿 𝐿𝐿𝐿𝐿𝑡𝑡 𝑑𝑑𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷 𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠 − 𝑉𝑉�⃑𝐿𝐿 𝐿𝐿𝐿𝐿𝑡𝑡 𝑎𝑎𝑆𝑆𝐷𝐷𝐷𝐷𝑇𝑇𝑅𝑅𝐷𝐷𝑎𝑎 =

𝑍𝑍⃑ = 𝑋𝑋⃑ 𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐 𝑌𝑌�⃑𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇

𝑌𝑌�⃑ 𝑍𝑍⃑ 𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐 𝑋𝑋� Figure 7: Left scap coordinate system marked and labeled on a dog, to show the orientation of each axis as well as the direction of rotation about each axis. Origin at Left SC-2.

Right Scap Coordinate system

= ⃑ �⃑𝑅𝑅𝑅𝑅𝑅𝑅 ℎ𝑡𝑡 𝑎𝑎𝑆𝑆𝐷𝐷𝐷𝐷𝑇𝑇𝑅𝑅𝐷𝐷𝑎𝑎 �⃑𝑅𝑅𝑅𝑅𝑅𝑅ℎ𝑡𝑡 𝑆𝑆𝑆𝑆−2 𝑋𝑋 𝑉𝑉 = − 𝑉𝑉

𝑌𝑌�⃑𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇 𝑉𝑉�⃑𝑅𝑅𝑅𝑅𝑅𝑅 ℎ𝑡𝑡 𝑑𝑑𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷 𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠 − 𝑉𝑉�⃑𝑅𝑅𝑅𝑅𝑅𝑅 ℎ𝑡𝑡 𝑎𝑎𝑆𝑆𝐷𝐷𝐷𝐷𝑇𝑇𝑅𝑅𝐷𝐷𝑎𝑎 =

𝑍𝑍⃑ = 𝑋𝑋⃑ 𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐 𝑌𝑌�⃑𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇

𝑌𝑌�⃑ 𝑍𝑍⃑ 𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐 𝑋𝑋�

Figure 8: Right scap coordinate system marked and labeled on a dog, to show the orientation of each axis as well as the direction of rotation about each axis. Origin at right SC-2.

Scapula Tracking Coordinate system

𝑋𝑋⃑ 𝑉𝑉�⃑𝐴𝐴 𝐴𝐴𝐷𝐷𝐷𝐷𝑇𝑇𝑅𝑅𝐷𝐷𝑎𝑎= − 𝑉𝑉�⃑𝑆𝑆𝑆𝑆−2

𝑌𝑌�⃑𝑇𝑇𝑇𝑇𝑇𝑇= 𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇 𝑇𝑇 𝑉𝑉�⃑𝑆𝑆𝑆𝑆−1 − 𝑉𝑉�⃑𝐴𝐴 𝐴𝐴𝐷𝐷𝐷𝐷𝑇𝑇𝑅𝑅𝐷𝐷𝑎𝑎

𝑍𝑍⃑ = 𝑋𝑋⃑ 𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐 𝑌𝑌�⃑𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇

𝑌𝑌�⃑ 𝑍𝑍⃑ 𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐 𝑋𝑋�

FigureFigure 8 7 Left Left scapula Scapula coordinate coordinate system system definition definitionFigure 6 Pelvis coordinate axis

Pelvis Coordinate system

+ + = 2 2 �𝑉𝑉�⃑𝑅𝑅−1 𝑉𝑉�⃑𝑅𝑅−2� �𝑉𝑉�⃑𝐿𝐿−1 𝑉𝑉�⃑𝐿𝐿−2� ⃑ 𝑍𝑍 −+ + = 2 2 �𝑉𝑉�⃑𝑅𝑅−1 𝑉𝑉�⃑𝐿𝐿−1� �𝑉𝑉�⃑𝑅𝑅−2 𝑉𝑉�⃑𝐿𝐿−2� ⃑𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇 𝑋𝑋 = −

𝑌𝑌�⃑ = 𝑍𝑍⃑ 𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐 𝑋𝑋 �𝑇𝑇𝑇𝑇𝑇𝑇 𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇

𝑋𝑋 ⃑ 𝑌𝑌�⃑ 𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐 𝑍𝑍̂

Figure 6: Pelvis coordinate system marked and labeled on a dog, to show the orientation of each axis as well as the direction of rotation about each axis. Origin at left iliac crest.

Using the above axis definitions, the rotation of the trunk, vest, left scapula, right scapula, and

pelvis relative to the “dog reference axis” was determined for each frame of data using Euler

rotation matrices31. The frames were then split into gait cycles using cycle frame data calculated

as described in the swing/stance section. The range of motion (ROM) defined as the difference

between the minimum angles of rotation from the maximum angles of rotation was collected for each gait cycle. The treatments were the three different vest conditions and the three days that data was collected. These data were reduced to a single measurement by averaging the ROM over the multiple gait cycles in a given day. That is, the average ROM for each time a single dog walked on the treadmill was calculated for each dog on each of the three days that the dog was on the treadmill and for each of the vest conditions. The ROM about the x-axis, the y-axis and the z-axis of the different reference systems was determined. Appendix C shows the mean

ROM, standard deviation, and number of cycles for each dog each day. A repeated measure

ANOVA 31 was used to analyze this ROM data with significance differences defined a p<=.05.

When conditions violated Mauchly's Test of Sphericity, the Greenhouse-Geisser correction was used in this analysis.

3.3 Walk Results

Figures 9 to 13 illustrate the differences that the two vests had on body segment rotation as the dogs walked on the treadmill. Compared to the no vest situation, both vests also significantly reduced (p<0.05) rotation of the pelvis about all three axes (Figure 9) however, there was no significant difference of this rotation when comparing the two vests.

Figure 9 Pelvis ROM data all vests walk

Figure 9: Average pelvis ROM about each axis measured in degrees at the walk. The dotted line represents adjustable vest data, the dashed line represents custom vest data, and the solid line represents no vest data.

29 For the left scapula segment, the custom vest significantly reduced (p<0.05) the rotation about

the x-axis while the adjustable vest significantly reduced (p<0.05) the rotation about the y-

axis. The vests had a similar effect on the rotation of the right scapula about the x-axis and the

y-axis (Figures 10, 11). Figure 10 Left scapula ROM all vests walk

Figure 10: Average left scapula ROM about each axis measured in degrees at the walk. The dotted line represents adjustable vest data, the dashed line represents custom vest data, and the solid line represents no vest data.

Figure 11 Right Scapula ROM all vests walk

Figure 11: Average right scapula ROM about each axis measured in degrees at the walk. The dotted line represents adjustable vest data, the dashed line represents custom vest data, and the solid line represents no vest data.

Both vests significantly reduced (p<0.05) trunk rotation about all three axes and both vests reduced this rotation differently. Trunk rotation about all three axes was significantly less

(p<.05) for the custom vest compared to the adjustable vest (Figure 12). Analysis of the vest Figure 13 rotation, while the dogs walked on the treadmill, indicated that the custom vest V t ROM

reduced the rotation about all three axes significantly (p<.05) more than the adjustable vest

(Figure 13). The differences in the trunk and vest ROM impact suggest that vest slippage did occur.

Figure 12: Average trunk ROM about each axis measured in degrees at the walk. The dotted line represents adjustable vest data, the dashed line represents custom vest data, and the solid lineFi gu represents no vest data.

Figure 13: Average vest ROM about each axis measured in degrees at the walk. The dotted line represents adjustable vest data; the dashed line represents custom vest data. There is no “no vest” data because the dog did not have a vest on in those trials.

Additionally, waveforms were calculated by finding the frame number for each percentage of the cycle and plotting the rotation angle for that frame. Plots shown in Appendix F are the average waveform across all of the dogs all of the days along with the 95% confidence interval for each segment during each treatment. Each percentage point for each cycle was averaged over 11 walk cycles and 18 trot cycles for each dog each day. The waveform for each dog each day was then used to create 95% confidence interval plots for all dogs all of the days combined (each dog has

3 samples). The solid line in the plots represents the mean of all of the samples, while the dashed line represents the confidence interval for each sample.

3.4 Trot Results

Figures 14 to 18 illustrate the differences that the two vests had on body segment rotation as the dogs trotted on the treadmill. The custom vest significantly reduced (p<0.05) the rotation of the pelvis about the x-axis and, while the adjustable vest also significantly reduced (p< .05) this rotation for day 1 and 2, results for the third day of data collection did not show significant differences (Figure 14). The custom vest significantly reduced (p<0.05) pelvis rotation about the y-axis while the adjustable vest did not have any effect (Figure 14). Neither vest changed pelvis rotation about the z-axis.

Figure 14: Average pelvis ROM about each axis measured in degrees at the trot. The dotted line represents adjustable vest data, the dashed line represents custom vest data, and the solid line represents no vest data.

Figure 14 P l i ROM 32

For the left scapula rotation, the adjustable vest significantly reduced (p<0.05) the rotation about

the y-axis but the custom vest had no impact. Neither vest changed the rotation about the z-axis.

The custom vest significantly reduced (p<0.05) only the rotation of the right scapula about the x- axis (Figures 15, 16) and the adjustable vest had no impact on the rotation of the right scapula.

Figure 15: Average left scapula ROM about each axis measured in degrees at the trot. The dotted line represents adjustable vest data, the dashed line represents custom vest data, and the solid line represents no vest data. Fig

Figure

Figure 16: Average right scapula ROM about each axis measured in degrees at the trot. The dotted line represents adjustable vest data, the dashed line represents custom vest data, and the solid line represents no vest data.

33 Similar to the results for the walking gait data, both vests significantly reduced (p<0.05) trunk rotation about the x-axis with both vests having similar changes in the magnitude of this ROM

(Figure 17). While both the custom vest and adjustable vest significantly reduced (p<0.05) trunk rotation about the z-axis (Figure 17), only the custom vest had a significant effect (p<0.05) on the rotation about the y-axis (Figure 17). Analysis of the vest rotation, while the dogs trotted on the treadmill, indicated that the custom vest significantly reduced (p<0.05) the rotation about the x-axis and the y-axis more than the adjustable vest (Figure 18) while the rotation about the z-axis was similar for both vest (Figure 18). The similarity in the trunk and vest ROM impact suggests that vest slippage did not occur in either vest.

Figure 17: Average trunk ROM about each axis measured in degrees at the trot. The dotted line Fig ure represents adjustable vest data, the dashed line represents custom vest data, and the solid line represents no vest data.

Fig

Figure 18: Average vest ROM about each axis measured in degrees at the trot. The dotted line represents adjustable vest data; the dashed line represents adjustable vest data. There is no “no vest” data because the dog did not have a vest on in those trials.

34 Similar to the walk, waveforms were also calculated for the trot data by finding the frame

number for each percentage of cycle and plotting the rotation angle for that frame. Plots shown

in Appendix G illustrate the average waveform across all the dogs all the days along with the

95% confidence interval for each segment during each treatment. Each percentage point for each

cycle was averaged over 11 walk cycles and 18 trot cycles for each dog each day. The waveform

for each dog each day was then used to create 95% confidence interval plots for all dogs all of

the days combined (each dog has 3 samples). The solid line in the plots represents the mean of

all of the samples, while the dashed line represents the confidence interval for each sample.

3.5 DISCUSSION

The two vests used in this study were of different designs and finding that movement of each

vest was different was anticipated. During the walking gait, the body segment impacted the most by the vests was the pelvis. The kinematic data indicated that both vests reduced the ROM about all three axes of rotation, indicating that the vest completely changed the natural movement of the pelvis. This result could be significant from a clinical perspective; hip dysplasia is a common orthopedic issue in large breeds so a finding that the vest might further impact abnormal pelvic joint motion may be reasonably anticipated and have clinical significance. A future study that measures the pelvic hip angles should be considered where the focus is to determine whether the impact vests have on the dog’s gait can contribute to hip problems and other clinically common joint problems.

Both vests also significantly reduced rotation of the trunk during the walking gait. The clinical relevance of these findings would require more studies where the trunk is measured, to help understand whether this reduction in trunk rotation could have a clinical effect. It is also important to note that at the walk, both vests did not follow the motion of the trunk during gait

suggesting that vest slippage occurred. The magnitude of the rotation differences was 1 to 2 degrees which could be minimal with regards to slippage.

Using either the right scapula or the left scapula for rotation measurements provided similar and consistent data during the walking gait. Interestingly, the custom vest influenced the ROM about the x-axis, while the adjustable vest influenced rotation about the y-axis. The different impact on the rotation using each of the vests could be due to the variation in the two vest designs. An additional study, which marks the entire front leg showing how the joints were affected, could help establish the preferred design from a clinical perspective.

Based on results from the trotting tests, the vests had less of an impact on the pelvis and scapula segments. However, there was more of an impact on the trunk ROM. The trunk ROM about all three axes was reduced by the custom vest. Both vests reducing the ROM similarly for both the x-axis and z-axis. ROM about the y-axis was interestingly only effected by the custom vest, while the adjustable vest did not seem to reduce the ROM about the y-axis at all. While it may be anticipated that the custom vest would have less of an effect on the gait because it is made specifically to fit the dog, a reason for the custom vest having a larger impact could be due to the overall design of the two vests. As shown in Figure 5, the custom vest had fabric covering the whole trunk, while the adjustable vest left a lot of the dog bare. As previously discussed, the clinical relevance of the effect the custom vest had on the trunk ROM is still unknown, but the findings of this study suggest that fabric surrounding the entire dog (Figure 5) could potentially have a direct effect on the dog’s gait.

For the pelvis, neither vest significantly affected the ROM about the z-axis. While both vests reduced the ROM about the x-axis and y-axis, the adjustable vest only showed significant differences for two of the days while the custom vest showed significant differences all 3 days.

This variability in the measurements over multiple days could suggest that all of the dogs were not fully acclimated to trotting in the vests. While efforts were made to acclimate the dogs in this study, more training time could potentially help ensure acclimation has occurred prior to data collection. .

The trot scapula data was slightly different compared to the walk scapula data when examining the results for the adjustable vest. Significant impact on the ROM about the y-axis was found for the left scapula, but not the right scapula. However, no other changes in the rotation data were found. These results could indicate that the adjustable vest impacts one side of the upper

portion of the dog more than the other side or potentially the fitting of the adjustable vest differs

for the two sides. While efforts were made to make sure the vests were properly fitted (the same

person put the vests on each dog, each day) there is a chance that one strap was tighter around

the scapula than the other. The custom vest has limited room for adjustments and as a result

could explain why the custom vest influenced the ROM of both scapulae instead of just one.

Similar to the suggestions for the walk data, marking the entire front leg to measure joint angles could help establish the clinical significance of these changes. Overall, more research to explain the clinical relevance of these data is still needed and marking more of the leg of the dog could

help make this clinical connection. The results of this study did however prove that these vests

do have an effect on a dog’s normal gait, and the different vest designs seem to effect the dogs

differently.

37 CHAPTER 4: CONCLUSIONS AND FUTURE WORK

Overall, this study achieved the goal of establishing a method for measuring truncal rotation and

using the established method to analyze the effect service vests have on canine gait. The findings

in this study reveal many future opportunities to further analyze the effect service vests have on

canine gait.

4.1 STUDY LIMITATIONS

A major limitation in this study was the availability of dogs. The use of dogs from different

breeds can lead to data variability, particularly dog to dog variability. Investigating the

kinematics of trunk rotation using a larger group of dogs could potentially eliminate some of the

variability. However, the study’s findings do provide the baseline data that outlines expectations

of similar vest studies. The varying effect these vests had on each dog could suggest that dogs

with a specific gait may benefit from certain vest designs more so than dogs with a different gait.

A future study using larger groups of dogs with similar gait patterns could help give insight to

this concept.

Another limitation in this study was the varying degrees of acclimation to the treadmill and/or

the vests. While efforts were made to acclimate dogs, the use of client owned dogs made it

difficult to have dogs come into the lab on a strict schedule and validate that each dog had the

same level of acclimation. A major goal of this study was to establish a method for quantifying

the rotation of various body segments, particularly the trunk, but full acclimation of the dogs

may not have occurred impacting these kinematic measurements. A future study using research dogs that are more accessible could help verify each dog was at the same level of acclimation.

Preliminary data comparing treadmill to over-ground data could also help verify that dogs are

fully acclimated to the treadmill. To eliminate the potential variable of treadmill acclimation, an

over-ground study instead of using the treadmill would be ideal, but this may be difficult because

this method requires both sides of the dog to be visible at all times and there is potential for a handler to block markers.

The final major limitation of this study was the number of cameras used, which made collecting marker data of the entire leg difficult. Marking the leg of the dog could allow researchers to compare data on the effect the vests are having on the joints to data from the literature on joint motion. This study did not mark the entire leg because the limited number of cameras made tracking these markers difficult and the main focus of the study herein was to establish a method

for measuring truncal rotation, not assess changes in leg kinematics as the dog walked and trotted

on a treadmill. This study presents a way to look at each individual segment alone, which could

have significant clinical relevance. Changes in the segment kinematics could be compared to

changes in the leg kinematics, which are more commonly reported in canine gait investigations,

to provide more clinical relevance.

4.2 RECOMMENDATIONS FOR FUTURE WORK

Chapter 1 described the various uses of canine service vests. These vests are used for a broad

range of purposes, from carrying supplies to acting as a harness for lifting dogs in and out of

helicopters. Using the method described in this study, vest designers could potentially test more

innovative designs that they may not have considered in the past. The biggest health risk for

military working dogs and a leading cause of death is heat stroke27. The current service vests

could be contributing to this heat exhaustion. The custom vest used in this study had fabric that

covered the entire trunk of the dog, which could be contributing to the dogs overheating, and

potentially be unnecessary. Future studies that compare the effect new vest designs, made of new

materials or simply less fabric, have on the dogs to the current vests in use could prove very valuable and potentially improve the dogs’ performance and lengthen their time of service.

In addition to testing different materials, this method could be used to help figure out the best way to pack a vest. Ideal weight distribution may vary from dog to dog, and this method could help researchers determine the ideal weight distribution when packing vests.

4.3 CONCLUSIONS

The study herein provided evidence that trunk rotation during gait could be quantified using the method reported in the findings. While there were limitations, this study was able to prove the rigidity of the segments in question and validate the method for measuring trunk rotation by showing no significant differences in the ROM data over multiple days. Future studies that mark the entire dog and use a larger, more acclimated group of dogs could help to provide clinical relevance of this data and further validate this method.

REFERENCES

1. Anderst, W.J., C. Les, and S. Tashman, In vivo serial joint space measurements during dynamic loading in a canine model of osteoarthritis. Osteoarthritis Cartilage, 2005. 13: p. 808. 2. Caron, A., et al., Kinematic gait analysis of the canine thoracic limb using a six degrees of freedom marker set. Veterinary and Comparative Orthopaedics and Traumatology (VCOT), 2014. 27(6): p. 461-469. 3. Gage, J.R., The clinical use of kinematics for evaluation of pathological gait cerebral palsy. J Bone Joint Surg Am, 1994. 76: p. 622. 4. Guillou, R.P., et al., Three Dimensional Kinematics of the Normal Canine Elbow at the Walk and Trot. Veterinary Surgery, 2011. 40(7): p. E30. 5. Korvick, D.L., G.J. Pijanowski, and D.J. Schaeffer, Three-dimensional kinematics of the intact and cranial cruciate ligament-deficient stifle of dogs. J Biomech, 1994. 27: p. 77. 6. Richards, J., et al., A comparison of human and canine kinematics during level walking, stair ascent, and stair descent. Wien Tierarztl Monatsschr, 2010. 97: p. 92-100. 7. Tashman, S., W. Aderst, and P. Kolowich, Kinematics of the ACL-deficient canine knee during gait: serial changes over two years. J Orthop Res, 2004. 22: p. 931. 8. Torres, B.T., et al., Comparison of canine stifle kinematic data collected with three different targeting models. Vet Surg, 2010. 39(4): p. 504-12. 9. Caron, A., et al., Kinematic gait analysis of the canine thoracic limb using a six degrees of freedom marker set. Study in normal Labrador Retrievers and Labrador Retrievers with medial coronoid process disease. Vet Comp Orthop Traumatol, 2014. 27(6): p. 461-9. 10. Torres, B.T., et al., The effect of marker location variability on noninvasive canine stifle kinematics. Vet Surg, 2011. 40(6): p. 715-9. 11. Kim, S., et al., Skin movement during the kinematic analysis of the canine pelvic limb. Veterinary and Comparative Orthopaedics and Traumatology (VCOT), 2011. 24(5): p. 326-332. 12. Fu, Y.-C., B.T. Torres, and S.C. Budsberg, Evaluation of a three-dimensional kinematic model for canine gait analysis. American journal of veterinary research, 2010. 71(10): p. 1118-1122. 13. Lu, T.W. and J.J. O'Connor, Bone position estimation from skin marker co-ordinates using globla optimisation with joint constraints. J Biomech, 1999. 32: p. 129. 14. Veldpaus, F.E., H.J. Woltring, and L.J. Dortmans, A least-squares algorithm for the equiform transformation from spatial marker coordinates. J Biomech, 1988. 21: p. 45. 15. Andriacchi, T., et al., A point cluster method for in vivo motion analysis: applied to a study of knee kinematics. Journal of biomechanical engineering, 1998. 120(6): p. 743-749. 16. van Andel, C., et al., Recording scapular motion using an acromion marker cluster. Gait & Posture, 2009. 29(1): p. 123-128. 17. Torres, B.T., et al., Pelvic limb kinematics in the dog with and without a stifle orthosis. Veterinary Surgery, 2017: p. n/a-n/a. 18. Gradner, G., et al., Kinematic study of back movement in clinically sound malinois dogs with consideration of the effect of radiographic changes in the lumbosacral junction. Veterinary surgery, 2007. 36(5): p. 472-481. 19. Foss, K.D., Kinetic and kinematic gait analysis in Doberman Pinschers with and without cervical spondylomyelopathy. 2012, The Ohio State University. 20. Stolze, H., et al., Gait analysis during treadmill and overground locomotion in children and adults. Electroencephalography and Clinical Neurophysiology/Electromyography and Motor Control, 1997. 105(6): p. 490-497.

21. Abdelhadi, J., et al., Fore-Aft Ground Force Adaptations to Induced Forelimb Lameness in Walking and Trotting Dogs. PLOS ONE, 2012. 7(12): p. e52202. 22. Fanchon, L. and D. Grandjean, Habituation of healthy dogs to treadmill trotting: repeatability assessment of vertical ground reaction force. Res Vet Sci, 2009. 87(1): p. 135-9. 23. Gustas, P., et al., Kinematic and temporospatial assessment of habituation of Labrador retrievers to treadmill trotting. Vet J, 2013. 198 Suppl 1: p. e114-9. 24. Helms, G., et al., Multi-body simulation of a canine hind limb: model development, experimental validation and calculation of ground reaction forces. Biomed Eng Online, 2009. 8: p. 36. 25. Riley, P.O., et al., A kinematic and kinetic comparison of overground and treadmill walking in healthy subjects. Gait & Posture, 2007. 26(1): p. 17-24. 26. Bockstahler, B.B., et al., Correlation of Surface Electromyography of the Vastus Lateralis Muscle in Dogs at a Walk with Joint Kinematics and Ground Reaction Forces. Veterinary Surgery, 2009. 38(6): p. 754-761. 27. Bruchim, Y., et al., Heat stroke in dogs: a retrospective study of 54 cases (1999–2004) and analysis of risk factors for death. Journal of veterinary internal medicine, 2006. 20(1): p. 38-46. 28. Gorton, George E., David A. Hebert, and Mary E. Gannotti. "Assessment of the kinematic variability among 12 motion analysis laboratories." Gait & posture 29.3 (2009): 398-402. 29. Kadaba, M. P., et al. "Repeatability of kinematic, kinetic, and electromyographic data in normal adult gait." Journal of Orthopaedic Research 7.6 (1989): 849-860.

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APPENDICES

APPENDIX A: Description of which segment each marker is located on, along with the size marker used. Large markers have an approximate width of 2 cm and height of 2 cm, medium markers have an approximate width of 1.5 cm and height of 2 cm, small markers have an approximate width of 1 cm and height of 1.5 cm.

SEGMENT LOCATION MARKER SIZE Custom vest R-1 Medium Custom vest R-2 Medium Custom vest L-1 Medium Custom vest L-2 Medium THORAX Adjustable/no vest R-1 Medium Adjustable/no vest R-2 Medium Adjustable/no vest L-1 Medium Adjustable/no vest L-2 Medium T-1 Large T-13 Large Xiphoid Large Lt Dorsal Scapula Medium LEFT SCAPULA Lt Spinal scapula Small Lt acromion/spinal scapula cluster Medium Rt Dorsal Scapula Medium RIGHT SCAPULA Rt Spinal scapula Small Rt acromion/spinal scapula cluster Medium Rt iliac crest Small PELVIS Lt iliac crest Small Rt ischium Medium Lt ischium Medium Custom Vest T-1 Large Velcro CUSTOM VEST Custom Vest T-13 Large Velcro Custom Vest Xiphoid Large Velcro Adjustable Vest T-1 Large Velcro ADJUSTABLE VEST Adjustable Vest T-13 Large Velcro Adjustable Vest Xiphoid Large Velcro

TOE Rt 5th Metatarsal Large Lt 5th Metatarsal Large

43 APPENDIX B: Protocol for each testing day

44 APPENDIX C: Rigidity tables for determining dog local axis for all dogs: Mean and standard deviation for the pelvis vector magnitudes in meters over 2000 frames of data (10 seconds) for the walk and trot for each dog

Dog 1 Dog

Dog 2 Dog

Dog 3 Dog

Dog 4 Dog

Dog 5 Dog

49 APPENDIX D: ROM Average and standard deviation (m) all dogs, all vests

Walk

Pelvis

Walk Trunk

Walk Vest Vest

Walk Right Scapula

Left Scapula Walk Scapula Left

APPENDIX E: ROM Average and standard deviation (m) all dogs, all vests

Trot

Pelvis

Trunk Trot

Vest Trot Vest

Right Trot Scapula

59 APPENDIX F:AverageWaveformand95%Confid

4 STANC SWIN E G 2 0 2 4 6 010 20 30 40 50 60 70 8090 10 0

STANC SWIN

60 4 E G 3

1 ence intervalplotswalk

0 010 20 30 40 50 60 70 80 90 10 1 0

3 4

STANC SWIN 1. E G 8 1. 3 0. 8 0. 3 0. 2 0. 7 010 20 30 40 50 60 70 80 90 10 0 5 STANCE SWING 3

5 0012003045006078090100

SWING 5 STANCE

61 4 3 2 1 0 1 2 3 4 0010203045006070890100

1.2 STANCE SWING 1 0.8 0.6 0.4 0.2 0 0.2 0.4 00102030450060708 90 100 SWING 8 STANCE 6 4 2 0 2 01020 034050067008 90 100

STANCE SWING 6 62 4 2 0 2 4 6 0010203045006070890100

STANCE SWING 5 4 3 2 1 0 1 01020 03045006070890100 SWING 8 STANCE 6 4 2 0 2 4 6 8 01020 03405006700890100

STANCE SWING 10

63 5 0 5 10 15 20 25 30 0010203045006070890100

STANCE SWING 25 20 15 10 5 0 5 10 01020 03045006070890100 8 STANCE SWING 6 4 2 0 2 4 6 8 0010203045006070890100

10 STANCE SWING 5

64 0 5 10 15 20 25 30 35 00102030450060708 90 100

10 STANCE SWING 5 0 5 10 15 20 0010203405006070890100 SWING 4 STANCE 3 2 1 0 1 2 3 01020 034050067008 90 100

STANCE SWING 2

65 1.5 1 0.5 0 0.5 1 1.5 2 2.5 0010203045006070890100

STANCE SWING 1.8

1.3

0.8

0.3

0.2

0.7 01020 030450060708 90 100 5 STANCE SWING 4 3 2 1 0 1 2 3 0012003405006700890100

SWING 2 STANCE 1.5 66 1 0.5 0 0.5 1 1.5 2 2.5 3 0010203045006070890100

0.25 STANCE SWING 0.2 0.15 0.1 0.05 0 0.05 0.1 0.15 0.2 0010203045006070890100 SWING 3 STANCE 2 1 0 1 2 01020 034050067008 90 100

STANCE SWING 7 67 5 3 1 1 3 5 7 0010203045006070890100

STANCE SWING 4.5 3.5 2.5 1.5 0.5 0.5 1.5 01020 030450060708 90 100 8 STANCE SWING

12 01020 034050067008 90 100

STANCE SWING 10

68 0 10 20 30 40 50 0010203045006070890100

STANCE SWING 30 25 20 15 10 5 0 5 01020 030450060708 90 100 8 STANCE SWING

12 0010203045006070890100

10 STANCE SWING 5 69 0 5 10 15 20 25 30 35 40 0010203045006070890100

10 STANCE SWING 5 0 5 10 15 20 25 0010203405006070890100 70

Angle Angle Angle 12 17 0.5 0.5 1.5 12 10 8 3 2 7 8 6 4 2 0 2 4 6 1 0 1 00 00 00 1200 10 10 20 20 340500 30 30 STANCE STANCE STANCE 45 45 00 00 %GaitCycle %GaitCycle %GaitCycle 60 6700 60 70 70 89 8 890100 SWING SWING SWING 01 0100 90 0 0 71

Angle Angle Angle 3 2 1 0 1 2 3 4 5 6 17 12 10 10 7 2 3 8 5 0 5 01 00 01 10 0 0 0 0 20 20 20 30 30 34 STANCE STANCE STANCE 45 4500 05 00 00 %GaitCycle %GaitCycle %GaitCycle 60 60 67 70 70 00 890100 89 8 SWING SWING SWING 01 90 0 100 0 72

Angle Angle Angle 13 12 35 30 25 20 15 10 10 10 10 15 20 7 2 3 8 5 0 5 5 0 5 01 00 01 10 0 0 0 0 20 20 20 34 30 30 STANCE STANCE STANCE 45 05 45 00 00 00 %GaitCycle %GaitCycle %GaitCycle 60 67 60 70 00 70 89 8 89 SWING SWING SWING 90 01 01 100 0 0 0 0 73

Angle Angle Angle 11 16 1 6 9 4 10 40 35 30 25 20 15 10 22 17 12 0 5 7 2 3 5 00 00 00 10 10 10 20 20 20 30 30 340500 STANCE STANCE STANCE 4500 4500 %GaitCycle %GaitCycle %GaitCycle 60 60 60 70 70 70 SWING 890100 0100 90 8 890100 SWING SWING A PPENDIX G : Average Waveform and 95% Confidence interval plots trot Adjustable Vest Trot X Rotation

SWING 5 STANCE '3 1

-3 -5 -7 I -9 0 10 20 30 40 50 60 70 80 90 100

%Gait Cycle Y Rotation

STANCE SWING

74 I 2 0

-4 -6 -8 0 10 20 30 40 so 60 70 80 90 100 %Gait Cycle

Z Rotation

STANCE SWING 5 4 3

1 0 -1 -2 -3 I -4 0 10 20 30 40 50 60 70 80 90 100 %Gait Cycle 75 76 77 78 5 STANCE SWING 3 1 1

3 5 01020 034050067008 90 100

STANCE SWING 3 79 2 1 0 1 2 3 0010203045006070890100

STANCE SWING 5 4 3 2 1 0 1 2 3 4 01020 03045006070890100 7 STANCE SWING 5 3 1 1 3 5 0012003045006078090100

SWING 2 STANCE

80 1 0 1 2 3 4 00102030450060708 90 100

0.6 STANCE SWING

0.4

0.2

0.4 0010203045006070890100 SWING 8 STANCE 6 4 2 0 2 4 01020 034050067008 90 100

STANCE SWING 2

81 1 0 1 2 3 4 5 6 0010203045006070890100

STANCE SWING 8 6 4 2 0 2 4 6 01020 03045006070890100 8 STANCE SWING

12 01020 034050067008 90 100

STANCE SWING 10

82 0 10 20 30 40 50 0010203045006070890100

STANCE SWING 30 25 20 15 10 5 0 5 01020 03045006070890100 8 STANCE SWING

12 0010203045006070890100

10 STANCE SWING 5

83 0 5 10 15 20 25 30 35 40 00102030450060708 90 100

10 STANCE SWING 5 0 5 10 15 20 25 0010203405006070890100 84 85 86 87