Page 1
University of Central Florida University of Central Florida
STARS STARS
Honors Undergraduate Theses UCF Theses and Dissertations
2020
Inter-rater Reliability and Intra-rater Reliability of Synchronous Inter-rater Reliability and Intra-rater Reliability of Synchronous
Ultrasound Imaging and Electromyography Measure of the Ultrasound Imaging and Electromyography Measure of the
Lumbopelvic-hip Muscle Complex Lumbopelvic-hip Muscle Complex
Courtney Caputo University of Central Florida
Part of the Musculoskeletal System Commons
Find similar works at: https://stars.library.ucf.edu/honorstheses
University of Central Florida Libraries http://library.ucf.edu
This Open Access is brought to you for free and open access by the UCF Theses and Dissertations at STARS. It has
been accepted for inclusion in Honors Undergraduate Theses by an authorized administrator of STARS. For more
information, please contact [email protected] .
Recommended Citation Recommended Citation Caputo, Courtney, "Inter-rater Reliability and Intra-rater Reliability of Synchronous Ultrasound Imaging and Electromyography Measure of the Lumbopelvic-hip Muscle Complex" (2020). Honors Undergraduate Theses. 682. https://stars.library.ucf.edu/honorstheses/682
Page 2
INTER-RATER RELIABILITY AND INTRA-RATER RELIABILITY
OF SYNCHRONOUS ULTRASOUND IMAGING AND
ELECTROMYOGRAPHY OF THE LUMBOPELVIC-HIP MUSCLE COMPLEX
by
COURTNEY CAPUTO
A thesis submitted in partial fulfillment of the requirements
for the Honors in the Major Program in Kinesiology and Physical Therapy
in the College of Health Professions and Sciences
at the University of Central Florida
Orlando, Florida
Spring Term, 2020
Thesis Committee Chair: L. Colby Mangum, Ph.D., LAT, ATC
Page 3
ii
© 2020 Courtney Caputo
Page 4
iii
Abstract
Objective: The purpose of this study was to determine inter-rater and intra-rater reliability of
synchronous ultrasound imaging and electromyography measures of lumbopelvic-hip muscle
activity performed by a novice and an experienced investigator in healthy individuals.
Electromyography (EMG) has served as the gold standard for quantification of onset of muscle
activation; however, ultrasound imaging can visualize muscle activity when collected
simultaneously. Methods: A novice and experienced investigator collected a series of 3
ultrasound images at rest and 3 M-mode clips during contraction of each muscle while EMG
electrodes collected muscle activity. Muscles collected included: external oblique, erector spinae,
rectus abdominis, gluteus maximus, and gluteus medius. Participants were asked to return 48-72
hours for a second session. After all muscles were collected, muscle thickness was measured
from the US images and latency based on onset of activity from EMG was processed and
averaged. Results: Moderate inter-rater reliability (ICC2,k=.5-.7) was found for most thickness,
modulated thickness, and latency variables between the experienced and novice raters, however
rectus abdominis had poor reliability compared to the other muscles assessed. Intra-rater
reliability between sessions 1 and 2 for the novice rater revealed moderate reliability (ICC2,k=.5-
.7) in the abdominal muscles (external oblique, erector spinae, contracted rectus abdominis) and
poor reliability in the gluteal muscles. Conclusions: Modulated thickness values had the
strongest reliability for inter- and intra-rater reliability, when thickness measures were divided by
body weight in kilograms before analysis. Subcutaneous tissue, notably abdominal adipose, and
Page 5
iv
its role on participant positioning should receive added attention during training and instruction
of novice investigators during M-mode acquisition and timing of contraction with EMG
synchronization.
Page 6
v
Acknowledgements
I would like to express my deepest gratitude towards Dr. L. Colby Mangum for her
unconditional support and encouragement. I am forever grateful for everything she has helped
me accomplish. I would like to recognize and show my appreciation for my committee members
Dr. Hill and Dr. Schellhase. As well as thank them for their amazing advice. I would like to
recognize the invaluable assistance Sara Akbarpour provided throughout my study. Finally, I
wish to thank my friends and family who have been by my side throughout this entire journey
and continuously love and support my dreams.
Page 7
vi
TABLE OF CONTENTS
INTRODUCTION 1
METHODS 3
RESULTS 7
DISCUSSION 7
CONCLUSION 12
TABLES AND FIGURES 13
APPENDIX A: REVIEW OF LITERATURE 18
LUMBOPELVIC-HIP COMPLEX 19
CORE STABILITY 19
SPINAL STABILIZATION 20
RANGE OF MOTION 20
MEASUREMENT OF MUSCLE ACTIVITY 22
ULTRASOUND IMAGING 22
USI TRAINING 23
ELECTROMYOGRAPHY 24
EMG AND ITS CONNECTION TO USI 24
THICKNESS AND ACTIVATION 25
EMG AND USI SYNCHRONIZATION 26
RELIABILITY OF ULTRASOUND 26
INTER-RATER RELIABILITY 26
INTRA-RATER RELIABILITY 27
SIGNIFICANCE OF STUDY 29
APPENDIX B: ADDITIONAL METHODS 30
BIBLIOGRAPHY 45
Page 8
1
Introduction
The lumbopelvic-hip complex is comprised of muscles that act as global movers and local
stabilizers, which are all important for individuals to maintain control of core movement during
physical activity. Although superficial, the external oblique (EO) muscle provides rotational
support to the lateral abdominal wall. The rectus abdominus (RA) can be activated when
performing an abdominal crunch1 due to its function in trunk flexion and is equally as important
as the erector spinae (ES). The ES extends vertically along the vertebral column to maintain
posture and aids in trunk extension.2 These muscles within the lumbopelvic-hip complex play a
vital role in the support and stabilization of the spine. Other muscles like
the gluteus maximus (GMAX) and gluteus medius (GMED) are important
in hip rotation, extension, and pelvic stability. Primary and secondary injuries frequently
attributed to strains of these muscles can be debilitating in populations, such as non-specific low
back pain and patellofemoral pain.3 However, use of technology to analyze and monitor these
muscles can be beneficial and improve the interventions used for injured patients.
Ultrasound imaging is a non-invasive method to measure muscle size, shape, and thickness that
can be used to identify short-term or long-term changes in the muscles of the lumbopelvic-hip
complex. Musculoskeletal ultrasound imaging is currently used by a variety of health care
professionals, including radiologists, physicians of multiple specialties, sonographers, athletic
trainers, physical therapists, and occupational therapists. Ultrasound imaging can be used to
visualize muscle activity4 and has shown acceptable to excellent reliability in core muscle
thickness and activity in various positions.3,5
Page 9
2
Electromyography (EMG) measures muscle response or electrical activity when a muscle is
being stimulated or voluntarily contracted to capture motor unit action potentials. Surface EMG
has been used as a gold standard to quantify the extent of and timing of muscle activation,
however, it can be difficult to use effectively with deeper muscle tissue or with muscles that
overlap one another due to cross-talk of the EMG electrical signal.6 Collecting muscle activity
using both ultrasound imaging and EMG allows researchers and clinicians to visualize and
quantify muscle changes in spatial and electrical manners. This is useful in assessment of a
variety of musculoskeletal injuries and chronic conditions. Ultrasound imaging and EMG have
been used for biofeedback in rehabilitation settings to show the patient how to improve their
muscle activity by visualizing their own muscle activity either on the ultrasound screen or on the
EMG output device.7,8
Clinicians commonly use ultrasound imaging and EMG to effectively assess and monitor muscle
activity. Using musculoskeletal anatomy knowledge and defined landmarks from ultrasound
imaging and EMG literature, the probe and electrodes can be positioned appropriately, and
monitoring can take place. With these aforementioned skills and training, a novice may be
able to acquire these same data from patients and research participants. Reliability as well as the
comparison of a novice and experienced rater should be established prior to moving forward with
a synchronized ultrasound imaging and EMG technique. An assistant or aid who can do such
actions with fundamental training can allow for clinicians and researchers using this
technique to integrate those individuals into their practice and research studies seamlessly.
Page 10
3
The purpose of this study was to determine inter-rater and intra-rater reliability of synchronous
ultrasound imaging and EMG of lumbopelvic-hip muscle activity performed by a novice and an
experienced investigator in healthy individuals. Our study aimed to show that even a novice with
a short amount of quality training can utilize this tool in a useful manner, specifically for
musculoskeletal ultrasound imaging. To our knowledge, prior research has not established
reliability in the lumbopelvic-hip muscles using this methodology.
Methods
Study Design
A descriptive laboratory study was used to assess inter-rater and intra-rater reliability in muscle
thickness at rest, during contraction, modulated rested and contracted thickness measures, and
latency values using synchronous ultrasound and EMG of the EO, RA, ES, GMAX, and GMED
of the lumbopelvic-hip complex. All measures were collected by two investigators, one novice
and one experienced, during two different sessions 48-72 hours apart.
Participants
Sixteen healthy participants without a history of low back, core, or hip injury participated in this
study. Individuals who reported any previous injuries or surgeries to the lumbopelvic-hip region
or lower extremities were excluded from this study. Participants’ ages ranged between 18-
45 years. Once in the lab, participants were given several questionnaires to evaluate their
physical fitness and activity level as well as to ensure no previous lower back or extremity pain
Page 11
4
or injuries. Written informed consent was obtained from all participants and the study protocol
was approved by the University’s Institutional Review Board.
Instruments
In addition to questionnaires on health history and physical activity, a SPI-Tronic Pro 360 digital
inclinometer was used to measure and document range of motion for each participant. A hand-
held dynamometer (microFET®2, Hoggan Scientific, LLC., Salt Lake City, Utah) was used to
measure and record maximum volitional isometric contraction (MVIC) force output in N/kg
of all muscles. A portable GE NextGen LOGIQ e (GE Healthcare, Waukesha, WI) ultrasound
unit with a linear transducer was used to visualize brightness mode (B-mode) and motion mode
(M-mode) ultrasound output. To measure onset of electrical muscle activity, a Delsys
Trigno wireless system (Delsys, Inc., Boston, MA) with Trigno Avanti sensors captured surface
EMG data and EMGworks® 4.54 (Delsys, Inc., Boston, MA) was utilized for EMG acquisition.
A standard Dell (Dell, Inc., Round Rock, TX) Latitude 7490 running Windows 10 collected,
stored and analyzed data throughout the study.
Data Collection
All participants completed questionnaires and surveys about their musculoskeletal injury
history, and physical activity level. Following the collection of these questionnaires, height,
weight, and trunk range of motion (trunk flexion, trunk extension, hip abduction, hip
extension) were collected using the inclinometer. Participants had surface EMG electrodes
placed in the areas on the muscles of interest for this study, the EO, RA, ES, GMAX,
Page 12
5
and GMED on the participant’s dominant side.9 Dominant side was self-reported on the
questionnaires. Once the adhesive electrodes were placed, the ultrasound gel was applied in each
area corresponding to the muscle of interest in the order listed above. The novice and
experienced rater collected a series of 3 ultrasound images at rest and during contraction using
B-mode. The other rater was not present in the room or able to view the screen when they were
not actively collecting. A random number generator was used to determine the order of rater for
each session and allocation was concealed until the start of each session. Following B-mode
imaging, 3 image clips during contraction while the EMG electrodes were collecting muscle
activity, were recorded.10 M-mode or motion mode was used on the ultrasound unit for this series
of contractions for each muscle.11 During M-mode collection, there was an EMG sensor attached
to the USI cart handle with non-adherent tape, to note when the activation of the contraction of
each participant was initiated (when the rater cued the participant to contract). After the rater
began the EMG recording, they initiated the M-mode recording, then immediately the EMG
sensor was tapped causing a spike in electrical activity on the system at the time that the rater
cued the participant to perform the contraction. The participant was then told to relax after
contraction, completing the 5-second interval of M-mode recording. All participants were asked
to return 48-72 hours later to repeat the same collection to determine intra-rater between session
reliability.12,13 After all muscles were collected, the muscle thickness was measured from the
ultrasound images and the delay, or latency, from cueing the participant and tapping the EMG
electrode, to the onset of electrical activity was measured using ImageJ (National Institutes of
Health, Bethesda, MD) and EMGworks (Delsys, Inc., Natick, MA), respectively.14 This data was
averaged from the 3 trials collected from each muscle.15 For EMG collection, a sampling rate of
Page 13
6
2000Hz was used. A band pass filter of 10-500Hz and a root mean square signal. The signal was
smoothed using a 50ms moving window for the 5-second contraction acquisition. Onset of
activation for the latency variable was defined as the amplitude exceeding 3 standard
deviations16, for greater than 0.25ms, above the baseline (quiet baseline) prior to the
synchronization tapping of the sensor on the USI cart. The novice and experienced investigator
data were compared to determine inter-rater reliability and between session reliability was
compared for intra-rater reliability for the novice.5,13
Statistical Analysis
Intraclass correlation coefficients (ICC2,k) were calculated with a two-way mixed model and 95%
confidence intervals to determine reliability of thickness measures, latency of contraction, and
the activity for both inter-rater and intra-rater. Excellent reliability was interpreted as values
above 0.9, good reliability was known as 0.75-0.9, moderate was noted as 0.5-0.75, poor was
shown to be less than 0.5.17 Paired t-tests were used to assess differences between sessions for
MVIC data from sessions 1 and 2. All reliability and paired t-tests statistical analyses were
conducted using SPSS version 25.0 (IBM Corp, Armonk, NY). Standard error of measurement
(SEM) and minimal detectable change (MDC) were calculated for all variables using Microsoft
Excel (Microsoft Office 365, Microsoft Corp., Redmond, WA). Alpha was set a-prior at ≤ 0.05.
Results
Participant characteristics are depicted in Table 1, including range of motion from session 1 and
strength data collected from both sessions. There were no differences between sessions in any
Page 14
7
muscle in hand-held dynamometry MVIC measures (N/kg). Muscle thickness at rest (cm), during
contraction (cm), muscle thickness modulated to body weight (cm/kg), activity ratios, and
latency in seconds are summarized for the novice and experienced raters from session 1 in Table
2. Inter-rater reliability between the novice and experienced raters was moderate for most
variables and is presented with SEM and MDC for each variable in Table 3. Outcomes of session
1 and 2 for the novice rater are provided in Table 4, followed by intra-rater reliability in Table 5.
GMED rested thickness revealed the highest inter-rater reliability (ICC2,k=.74), and GMAX had
the highest contracted thickness inter-rater reliability (ICC2,k=.63). Both GMAX and GMED had
consistently the highest inter-rater reliability for latency in timing of contraction delay with EMG
synchronization (ICC2,k=.51). The abdominal muscles had greater reliability for novice intra-
rater reliability compared to the gluteal muscles, as GMAX and GMED had poor reliability
(ICC2,k<0.2) or the average covariance of the variable was negative and the reliability model
assumptions were violated, resulting in a negative ICC value. Those variables are noted with a (-
-) in the ICC column (Tables 3 and 5).
Discussion
Reliability between a novice and experienced investigator, in addition to between session
reliability of a novice investigator were assessed in this study for M-mode ultrasound time-
synchronized with EMG of five different muscles in the lumbopelvic-hip complex. GMED had
the highest reliability for inter-rater reliability across all variables (Table 3) and EO was
consistently the most reliable muscle assessed for intra-rater reliability by the novice rater (Table
5). Inter-rater reliability produced acceptable, moderate results for most M-mode USI measures,
Page 15
8
which were time-synchronized with EMG onset of activation. The most reliable inter-rater
results were observed when thickness measures were modulated or normalized to body weight in
kilograms. The location of the muscles assessed in this study played a large role in the
contractions performed by the participants and therefore, the measurements acquired by the
raters. Each contraction was performed in order to show that specific muscle being activated. As
body size affected these measures directly, once body weight was adjusted for, most ICC values
improved, some dramatically. The modulated values gave a better representation of that
individual. This was a significant unexpected finding that should be considered when utilizing
this technique of synchronous USI and EMG.
Regarding ES it is important to note that the contour of all of the tissue presented a unique task
when placing the transducer and visualizing facial borders in all participants when using USI.3
The amount of posterior lumbar musculature in each of the healthy, active participants in the
current study added to the extra attention that had to be paid to placement of the ultrasound
transducer during ES image capture, especially during movement. Increased muscle tissue and/or
adipose tissue can make it challenging for even an experienced investigator to obtain an image of
the same quality. Lumbar multifidus has had poor reliability in any position beyond tabletop,
static positions in past studies.3 Inter-rater reliability of the novice and experienced investigators
showed ES measurement with consistent moderate reliability (ICC2.k=.56-.66). The added
attention paid to the placement of the transducer and visualization of the fascial borders by both
investigators may have led to this moderate level of reliability. Additional training and practice
Page 16
9
in this area was a focus for the novice due to its potential for increased change in muscle tissue
from rest to contraction.
RA had a larger discrepancy between raters compared to other muscles and positioning. RA also
had improved intra-reliability results with the novice investigator when contracted versus when
rested. This could be due to the fact that the facial borders were well defined once the participant
contracted and were unable to be detected amongst the tissue at rest. Measurements with
presence of abdominal fat may have been contributing factors to this inconsistency as well.
Although all participants met American College of Sports Medicine guidelines of a healthy
participant, this study did not incorporate a specific cut off for participants’ body mass index
(BMI). Considering BMI was not a limiting factor, some subjects did have a higher amount of
adipose and abdominal tissue than others as evidenced in the superficial regions of their RA
ultrasound images. This increased amount of tissue can play a major role in the ability to find
and visualize anterolateral muscles on the US. Individuals with increased subcutaneous tissue
necessitated the rater to increase the depth of the USI on-screen in order to get an accurate and
measurable image. To analyze the superior and inferior borders, the depth must be adjusted on
the USI unit and the appropriate depth must be selected before image capture and is up to the
individual rater’s discretion.
Females tend to have a higher percentage of body fat than males.18,19 It has been documented that
females are more effective at storing fat when compared to males.19 Females who have
additional adipose tissue around the lumbopelvic-hip area compared to their male counterparts
Page 17
10
need to be taken into consideration, when imaging the abdominal region. Although in our study
the proportion of females-to-males was fairly even (females=57%) in the sample, this should be
noted when looking at the reliability of the RA. Imaging a lean individual presented an easier
process of identifying facial borders, particularly for the novice rater. With larger individuals it is
harder to not only identify these borders amongst the tissue, but to also reproduce those images
consistently over time. EO exhibiting a higher intra-rater ICC2,k of 0.63 and 0.66 for rested and
contracted values, respectively supports this notion that there was an ease with visualization of
those facial borders with less subcutaneous tissue in the same view as the muscle of interest for
the novice rater.
Critical aspects that should also be reflected from the intra-rater reliability results include the
trend in reduction of variance from session 1 to session 2 seen in Table 4. Although, all the same
actions were taken in both instances the novice was able to have a better understanding when
locating and visualizing musculature and facial borders, the second time. This could be reflected
in the shift in most rested and contracted thickness measures for the novice rater. The novice
rater’s reliability was moderate and consistent for most of the abdominal muscle variables,
although subtle improvement over time was shown as the standard deviation for group means
decreased based on both the rested and contracted thickness. This could be a resultant learning
effect from the short time period between sessions of only 48-72 hours. The participant may have
had a much better understanding of the instructions given after hearing them several times.
It is also important to understand each subject was given the same instructions while the other
Page 18
11
rater was not in the room. Each follow-up session with participants was scheduled at a similar
time as their initial session, to avoid interference from changing of mealtimes or attending the
gym, which may have affected some of the abdominal images. Participants were scheduled to
meet 48-72 hours apart at the fixed time as their original session. Even though participants were
in a comfortable environment and given easy to follow directions they may have felt nervous
during the first session and did not give full effort during M-mode capture and contractions,
whereas in the second session they may felt increased confidence and put in added effort leading
to a disparity in thickness and latency. The opposite may have been true for some participants
where they put forth full effort to be impressive in session 1 and lessened their effort during the
second meeting thus altering reproducibility, which may have been especially true with RA. The
abdominal crunch required for the contraction for RA anecdotally was not the most favored
position of the participants throughout data collection and that may have affected overall effort
throughout the sessions and between investigators. Although there were no significant
differences between (p>.05) any of the MVIC strength assessments from session 1 to session 2,
the contractions performed during the M-mode and EMG collection were sub-maximal and may
not have elicited enough of a contraction to produce reliable results consistently.
Conclusion
Moderate, acceptable inter-rater reliability between a novice and experienced rater was found
amongst EO, ES, GMAX, and GMED thickness and modulated thickness, at rest and during
contraction. Intra-rater reliability of a novice between sessions revealed moderate reliability of
EO, ES, and contracted RA measures. Nearly all reliability improved for thickness measures
Page 19
12
when divided by body weight in kilograms and this adjustment is important for assessment in the
abdominal and hip areas. Visualization of the lumbopelvic-hip complex is multi-faceted and the
location of measurement, and nature of contraction should be considered when training a novice
rater for USI and EMG synchronous collection.
Page 20
13
Tables and Figures Table 1. Participant Characteristics
Characteristic
Age (years) 21.63±2.36
Height (cm) 169.08±7.44
Weight (kg) 66.86±12.72
Sex 9 female, 7 male
Dominant lower limb
(side of collection)
14 right, 2 left
Tegner Activity Scale 5.94±0.99
PROMIS Global Health 37.5±4.24
PROMIS Physical
Function
99.13±1.15
Range of Motion (°)
Trunk Flexion 35.98±11.18
Trunk Extension 28.59±7.03
Right Hip Extension 23.44±6.44
Left Hip Extension 25.28±7.87
Right Hip Abduction 33.64±9.75
Left Hip Abduction 29.35±10.57
MVIC Force Output
(N/kg)
Session 1 Session 2
External Oblique 0.30±0.06 0.33±0.08
Erector Spinae 0.29±0.08 0.30±0.07
Rectus Abdominis 0.31±0.07 0.31±0.05
Gluteus Maximus 0.51±0.12 0.51±0.09
Gluteus Medius 0.61±0.17 0.57±0.13
Page 21
14
Table 2. Session 1 Results Summary
Group Means
(Standard Deviation)
Rested
thickness
(cm)
Modulated
rested thickness
(cm/kg)
Contracted
thickness
(cm)
Modulated
contracted
thickness
(cm/kg)
Activity ratio
(contracted/rested
thickness) Latency (s)
N E N E N E N E N E N E
External
Oblique
0.52
(0.17)
0.47
(0.17)
0.008
(0.003)
0.007
(0.003)
0.91
(0.29)
0.85
(0.24)
0.014
(0.006)
0.013
(0.004)
1.94
(0.77)
1.88
(0.44)
1.10
(0.42)
1.20
(0.36)
Erector
Spinae
1.39
(0.62)
1.87
(0.68)
0.022
(0.011)
0.029
(0.013)
2.03
(0.72)
2.51
(0.99)
0.032
(0.012)
0.039
(0.018)
1.56
(0.42)
1.41
(0.58)
1.44
(0.31)
1.31
(0.28)
Rectus
Abdominis
0.88
(0.33)
0.95
(0.37)
0.013
(0.004)
0.144
(0.006)
1.28
(0.46)
1.44
(0.42)
0.019
(0.005)
0.022
(0.008)
1.49
(0.33)
1.67
(0.67)
1.09
(0.54)
1.29
(0.40)
Gluteus
Maximus
0.61
(0.22)
0.79
(0.31)
0.009
(0.004)
0.013
(0.006)
0.82
(0.43)
1.27
(0.66)
0.012
(0.006)
0.019
(0.010)
1.35
(0.47)
1.67
(0.76)
1.30
(0.36)
1.36
(0.67)
Gluteus
Medius
1.06
(0.54)
1.26
(0.67)
0.016
(0.006)
0.019
(0.009)
1.36
(0.55)
1.65
(0.81)
0.021
(0.010)
0.025
(0.013)
1.41
(0.57)
1.35
(0.41)
1.02
(0.34)
1.25
(0.46)
Abbreviations: N, novice rater; E, experienced rater.
Page 22
15
Table 3. Inter-rater Reliability Summary of Results
Standard Error of
Measurement
Minimal
Detectable Change ICC2.k 95% Confidence Interval
External Oblique Lower Bound Upper Bound
Rested thickness (cm) .10 .28 .63 -.07 .87
Modulated rested
thickness (cm/kg) 0.0070 0.0094 .68 .09 .89
Contracted thickness
(cm) .19 .53 .45 -.58 .81
Modulated contracted
thickness (cm/kg) 0.0014 0.0040 .66 .04 .88
Latency (s) .36 1.00 .14 .01 .67
Erector Spinae
Rested thickness (cm) .37 1.03 .66 .01 .88
Modulated rested
thickness (cm/kg) 0.0027 0.0075 .71 .18 .90
Contracted thickness
(cm) .53 1.47 .56 -.26 .85
Modulated contracted
thickness (cm/kg) 0.0030 0.0084 .62 -.10 .87
Latency (s) .20 .56 .55 .09 .82
Rectus Abdominis
Rested thickness (cm) .32 .89 .15 .53 .60
Modulated rested
thickness (cm/kg) --
Contracted thickness
(cm) .27 .76 .61 -.13 .86
Modulated contracted
thickness (cm/kg) 0.0013 0.0036 .47 -.53 .81
Latency (s) .40 1.12 .20 -1.0 .72
Gluteus Maximus
Rested thickness (cm) .19 .52 .44 -.60 .81
Modulated rested
thickness (cm/kg) 0.00089 0.0025 .55 -.29 .84
Contracted thickness
(cm) .30 .84 .63 -.05 .87
Modulated contracted
thickness (cm/kg) 0.0016 0.0043 .55 -.29 .84
Latency (s) .34 .93 .51 .40 .83
Gluteus Medius
Rested thickness (cm) .31 .85 .74 .26 .91
Modulated rested
thickness (cm/kg) 0.0015 0.0042 .68 .08 .89
Contracted thickness
(cm) .49 1.34 .52 -.37 .83
Modulated contracted
thickness (cm/kg) 0.0025 0.0070 .74 .26 .91
Latency (s) .28 .78 .51 -.39 .83
Abbreviations: cm, centimeter; kg, kilogram; s, seconds.
Page 23
16
Table 4. Session 1 and 2 Results Summary for Novice Investigator
Group Means
(Standard Deviation)
Rested
thickness
(cm)
Modulated
rested thickness
(cm/kg)
Contracted
thickness
(cm)
Modulated
contracted
thickness
(cm/kg)
Activity ratio
(contracted/rested
thickness) Latency (s)
1 2 1 2 1 2 1 2 1 2 1 2
External
Oblique 0.52
(0.17)
0.50
(0.12)
0.008
(0.003)
0.008
(0.002)
0.91
(0.29)
0.76
(0.29)
0.014
(0.006)
0.012
(0.004)
1.94
(0.77)
1.51
(0.38)
1.10
(0.42)
0.91
(0.24)
Erector
Spinae 1.39
(0.62)
1.45
(0.31)
0.022
(0.011)
0.022
(0.006)
2.03
(0.72)
1.86
(0.30)
0.032
(0.012)
0.029
(0.007)
1.56
(0.42)
1.56
(0.35)
1.44
(0.31)
1.08
(0.37)
Rectus
Abdominis 0.88
(0.33)
0.86
(0.23)
0.013
(0.004)
0.013
(0.003)
1.28
(0.46)
1.31
(0.36)
0.019
(0.005)
0.20
(0.005)
1.49
(0.33)
1.33
(0.30)
1.09
(0.54)
1.00
(0.31)
Gluteus
Maximus 0.61
(0.22)
0.76
(0.14)
0.009
(0.004)
0.012
(0.003)
0.82
(0.43)
1.05
(0.24)
0.012
(0.006)
0.016
(0.005)
1.35
(0.47)
1.38
(0.25)
1.30
(0.36)
1.45
(0.48)
Gluteus
Medius 1.06
(0.54)
0.86
(0.31)
0.016
(0.006)
0.013
(0.005)
1.36
(0.55)
1.10
(0.33)
0.021
(0.010)
0.017
(0.005)
1.41
(0.57)
1.41
(0.39)
1.02
(0.34)
1.07
(0.45)
Abbreviations: cm, centimeter; kg, kilogram; s, seconds.
Page 24
17
Table 5. Novice Intra-rater Reliability Summary of Results
Standard Error
of Measurement
Minimal Detectable
Change ICC2.k 95% Confidence Interval
External Oblique
Lower
Bound Upper Bound
Rested thickness (cm) .08 .21 .57 -.24 .85
Modulated rested
thickness (cm/kg) .001 .003 .63 -.06 .87
Contracted thickness
(cm) .20 .55 .55 -.28 .84
Modulated contracted
thickness (cm/kg) .002 .006 .66 .03 .88
Latency (s) .15 .41 .64 -.04 .87
Erector Spinae
Rested thickness (cm) .22 .87 .49 -.48 .82
Modulated rested
thickness (cm/kg) .004 .017 .60 -.14 .86
Contracted thickness
(cm) .29 .84 .1 -1 .69
Modulated contracted
thickness (cm/kg) .005 .02 .61 -.12 .86
Latency (s) .25 .70 .53 -.35 .84
Rectus Abdominis
Rested thickness (cm) .21 .59 .12 -1 .69
Modulated rested
thickness (cm/kg) --
Contracted thickness
(cm) .19 .003 .73 .23 .91
Modulated contracted
thickness (cm/kg) 1.01 .01 .54 -.32 .84
Latency (s) .30 .83 .08 -1 .68
Gluteus Maximus
Rested thickness (cm) --
Modulated rested
thickness (cm/kg) .003 .009 .03 -1 .66
Contracted thickness
(cm) --
Modulated contracted
thickness (cm/kg) --
Latency (s) .34 .96 .49 -.45 .82
Gluteus Medius
Rested thickness (cm) --
Modulated rested
thickness (cm/kg) .005 .015 .01 -1 .66
Contracted thickness
(cm) .31 .91 .09 -1 .68
Modulated contracted
thickness (cm/kg) .004 .015 .42 -.65 .80
Latency (s) .39 1.09 .22 -1 .73
Abbreviations: cm, centimeter; kg, kilogram; s, seconds.
Page 25
18
Appendix A: Review of Literature
Page 26
19
Lumbopelvic Hip Complex
The lumbopelvic hip complex is known as the area that transitions from your lower to upper
body. Some of the major components of this complex are the rectus abdominus (RA), external
oblique (EO), erector spinae (ES), gluteus maximus (GMAX), and gluteus medius (GMED). The
role of these muscles including how they coordinate with one another for optimal function has
been extensively studied. These muscles as a whole work to be local stabilizers as well as global
movers.20,21 A global mover is known to move the load, while local stabilizers maintain
steadiness throughout the body during such movements. It is critical for our understanding to be
able to correctly visualize and examine this region in healthy individuals in order to aid and
assess the injured population such as those who suffer from low-back pain.22 Studies suggest
that the lumbopelvic hip complex not only plays a major role in the lower extremity movement
during daily tasks and our ability to do daily functions like use the stairs or squat, but it is just as
is important in functions in our upper body for activities like throwing.23
Core Stability
The core is comprised of the RA, transverse abdominus (TrA), EO, internal oblique (IO), ES as
well as piriformis, GMAX, gluteus minimus and GMED muscles.24 These muscles play a major
role in the function, stability and mobility of the core. Core stability is described as one’s ability
to provide strength and control the position and movement of their core complex. A person
having a stable core is said to have better balance and stability in everyday activities whether it
be moving or playing field hockey. Many studies focus on the importance of a stable
core.20,25,26,27,28,29,30 Research has shown that a less stable lumbopelvic hip complex and/or core
Page 27
20
will cause the body to place more pressure and strain on the specific area instead of using these
particular muscles.23 The ability to recognize, understand, and train your core for stability is so
significant and allows clinicians to prevent injuries and build endurance in athletes.26
Table 1.0 Global Muscles
Stabilizers Mobilizers
TrA RA
GMAX EO
GMED ES
IO
Spinal Stabilization
The primary goal of the spine is to provide strength and spinal stability in order to prevent and
treat the possibility of lumbar damage. The dynamics that affect lumbar stabilization have shown
to be important not only for patients, but for clinicians as well. Exercises that play a role in
enhancing the stabilization of the spine have been shown to have a positive impact on prevention
of injuries and treatments with low back pain when used in clinical settings.31,32 In addition,
patients who report low back pain are able to retrain their muscles and increase spinal stability
while decreasing symptoms of lower back pain by repeatedly doing lumbar stabilization
exercises.33
Range of Motion
Range of motion (ROM) can be determined using different tools and techniques. Goniometers
are a well-known tool for their reliability to measure ROM of joints. They consist of two arms
that can pulled apart or brought closer depending on the extent the patient is able to move. These
Page 28
21
two arms then determine the degree of the angle at which the patient can bend that joint (as
shown in the image depicted in figure 1.0). Another common way to measure ROM is through
the use of a digital inclinometer. By simply zeroing out the device the tool can then be placed on
the patient and as they abduction/adduct the degree of inclination will be inputted. These devices
are a representation of the motions the joint can move when propelled by muscles meaning from
full flexion to the full extension. ROM is deeply connected and related to many aspects involving
our ability to function on a daily basis. Evidence shows improvement of ROM helps prevent
injuries and further suggests an improvement in trunk muscle strength tests.26 ROM is a
fundamental element in monitoring progress as well as pit falls in patient care plans in clinical
practice.34
Figure 1.0 Goniometer in Use
Measurement of Muscle Activity
Page 29
22
Ultrasound Imaging
Ultrasound imaging (USI) is a non-invasive technique that uses high-frequency sound waves to
produce images of structures within the body and can aid clinicians in the diagnosis and
treatment of medical conditions and other injuries. The use of USI is increasing amongst
healthcare providers.35 Recent studies have proven USI to be a reliable tool.36,37,38,39 USI are
reliable ways to measure the thickness of muscles by placing the transducer over the specified
muscle region and examining the diameter of the cross-sectional area of said muscle. Thickness
is determined by the distance between the inner edge of each fascicle border.40 USI yield
consistent results in a timely manner.41,42,43 The use of bed side ultrasound imaging can speed up
the process of decision making amongst clinicians and have a beneficial impact on patients when
an early diagnosis is critical.44,45,46,47 B-mode which stands for brightness mode is the most
commonly used method of USI. It is named brightness mode because it depicts 2D images by
transmitting sounds waves which are then either absorbed or reflected based on the water
content, the tissues of the muscles, the US gel, and other make ups in the surrounding area. Once
these sound waves have hit a boundary they are then reflected and recognized by the transducer
which in turn relay the image to the machine. USI works because they use echoes that can
transmit and depict an image during one instant compared to radiation which is a much more
complicated process. In contrast, M-mode stands for motion mode which illustrates time motion
display. The movement being seen on the screen allows for the tracking of facial borders to take
place from their position at rest through the muscle contraction and back to relaxation. Both B
and M-mode can be used to measure muscle thickness.48 However, M-mode plays a critical role
in collecting the duration of contractions in muscles since it is able to record the entire motion of
Page 30
23
the muscle. When combining the use of M-mode and EMG clinicians can evaluate the two time
domains that take place simultaneously and evaluate the excitation compared to the diameter of
muscle thickness.11
USI Training
A recent survey revealed the lack of musculoskeletal USI training among residents.35
Researchers note the importance and high demand of implementing simple training sessions that
can be from web modules or even peer taught.35 Other studies prove that we can successfully
teach novice students who plan to later become physicians the basics of interventional USI.49 Not
only is USI training achievable it is both valuable and economically favored for clinicians.49
Even emergency medicine residents have been able to confirm having only a short training
course and given basic knowledge of USI devices they can intubate patients.49,50 It has been
shown that implementation of simulator training can advance USI performance on radiology
residents compared to the students who received standard clinical training.51 In addition, USI
has been proven to be one of the fastest methods to confirm and determine necessary action not
only for injured athletes, but for anesthesia trainees in hospitals learning to intubate and place
endotracheal tubes in the esophagus. The use of US can help guide the trainee and direct them
toward the correct area.52
Electromyography
Page 31
24
Surface electromyography (sEMG) is another non-invasive way to assess muscles. Clinicians
and researchers are able to study their electrical activity and monitor changes in endurance. Strict
guidelines on musculoskeletal anatomy and proper sensor placement have been defined when
using sEMG.9 Before placement of sensor the skin must be prepared in order to get good to
excellent skin-electrode contact. Then the subject is to be positioned in the recommended posture
for that specific position. Following that the sensor is ready to be placed, it is to be located on a
point that lies between two anatomical landmarks. The specific position and orientation for every
muscle is based on two rules; 1. The sensor is to be placed halfway between the most distal
motor endplate and that tendon that is also located distally, and 2. The sensor is to be placed
within this region and not on the edge to maximize the distance between what is examined and
other muscles.9
EMG and its Connection to USI
The clinical standard when assessing electrical signals from the fibers of muscles and
interpreting their characteristic meaning and underlying pathological changes has always been
needle electromyography.53,54 The use of needle EMG permits inserting a needle into the patients
muscle and putting them at a higher risk of pain, bleeding and even pneumothorax.55 There is
evidence to validate that surface EMG and needle EMG can detect the same activation of
muscles when implemented.56 In the following study they noted the surface EMG and needle
EMG reflected dependable findings, but the surface EMG yielded higher velocity when
measuring the muscle fiber conduction.57
Page 32
25
Surface EMG and USI have both become an alternative for a subtle less invasive approach and
have been used simultaneously on patients when collecting data. When examining the leg, the
rate of agreement with US and sEMG was maximal, with a median of 30%, for single differential
recordings.53, 58 USI can cooperate with sEMG to achieve a more accurate human machine
interface when looking at finger motion recognition.59 The USI uses a higher resolution to be
able to depict the structural changes of muscles59, while EMG is less sensitive to spatial
arrangment.58
Thickness and Activation
The thickness of muscles has been measured through USI and compared with the electrical
activity during movement and contraction of muscles. The TrA, IO and EO have been studied
using such measures within a healthy population.60 This research showed after three exercises of
a drawing-in maneuver no change was seen throughout the EO and IO muscles, but a change in
thickness and strength of the TrA was seen.60 The drawing in maneuver is understood as the
activation of the transversus abdominus, the deepest muscle, in order to assist in stabilizing the
spine. Subjects are directed to bend knees to a 90-degree angle and lay in a supine position.
While in this position they are instructed to pick a focal point, place their hands on their head and
breathe out while pulling in the navel with continuous pressure.60 The RA is activated during
isometric movements such as supine trunk raise and supine bent leg raise which is seen in the
frequency changes of EMG.61 Using USI researchers compared the muscle thickness of IO, EO,
and TrA after being activated by a forced expiration.62 EO can also be activated when the torso is
being rotated and abducted. A common wat to quantify and measure neuromuscular function of
Page 33
26
GMAX and GMED is using the central activation ratio (CAR). CAR verifies isometric torque
movements of hip abduction and hip extension activates GMAX and GMED.63
EMG and USI Synchronization
USI and EMG diagnostics are together one of the most often used resources when examining
muscles. Muscle changes seen on the US data were closely linked with the spike changes on the
EMG.64 Systems such as the Teager-Kaiser Energy Operator (TKEO) have been set in place to
capture both the spikes with the images in a synchronized manner.11 The TKEO can detect
motion intensity using an algorithm which is common when using EMG. This motion intensity
can also be seen visually when muscle fascicles are being contracted and then later processed
with TKEO and the onset of the two signals (the EMG and the US) can then be compared.11
However, not having these custom programs to determine the exact timing of activation can
make this process extremely difficult and not allow for them to be integrated into many clinical
care facilities. With the use of M-mode clinicians can see the start and end of muscle activity. A
change in muscle thickness can be witnessed using USI when contraction takes place and during
the same interval as the muscle is activated to contract a spike can be seen on the EMG monitor
due to the excitation of muscle.11
Reliability of Ultrasound
Inter-Rater Reliability
Inter-rater reliability focuses on the consistency between raters or investigators. Intraclass
correlation coefficient (ICC), which measures the reliability using quantitative measures is
Page 34
27
important when defining reliability. An ICC of 1.0 represents a perfect agreement. Assessment of
the morphologic characteristics at rest and contracted showed good to excellent reliability with
ICC scores all above 0.85 with a 95% confidence interval between novice investigators.5
General investigations of the abdominal muscles and fasciae have determined good reliability of
raters with an ICC score of 0.83 when examining the fasciae and excellent reliability with an
ICC score of 0.99 when using USI to see the muscles.38 Other studies have been conducted using
2D and 3D USI with novice and expert raters when examining the hips of infants. Reliability of
inter-rater was poor for 2D USI, but moderate to high reliability for 3D USI.65 Inter-rater
reliability has overall showed to be a good and highly reliable source in daily clinical routines
when examining the architecture of gastrocnemius muscles.66
Intra-Rater Reliability
Intra-rater reliability is the uniformity between two sessions when conducting the same
investigation with the same rater. TrA, IO, and EO thickness was measured using USI at rest and
during contraction, revealing reliability between sessions.39 Using a single group and repeating
measures using USI, results clearly proved excellent reliability of measures of abdominal
muscles when using the straight leg test with an ICC score of 0.90.39 In the same hip study
mentioned in the earlier section raters examined intra- reliability and discovered accuracy was
higher for 3D USI when compared to the 2D USI.65 Using M-mode to observe intra-rater
reliability when assessing diaphragmatic motion resulted in accurate and reproducible
measurements yielding observer agreement ICC scores of 0.90 and 0.797. 67 In another instance,
two raters used USI to assess the pelvic tilt of healthy individuals and determined reliability to be
good to excellent with ICC scores above 0.86.68 Intra-reliability has been proven to be of feasible
Page 35
28
and of great clinical use in many other aspects and studies using USI such as on tendons, tissues
and other structures outside of the lumbopelvic hip complex.69,70,71 Although the focus is on the
lumbopelvic-hip complex these muscles and structures outside of the complex are still significant
in that they represent the various ways clinicians can use USI to enhance the body’s ability to
function better as a whole.
Page 36
29
Overall Significance of Study
Ultrasound imaging in trunk musculature has been investigated with similar methods5, but not
with this type of synchronous muscle activity collection. It must also first be established in a
healthy group of participants before testing in injured individuals and is the first study of its
kind. This study is impactful not only because this specific measurement technique has not been
explored in this manner, but because of the application potential to help clinicians successfully
aid injured patients through their rehabilitation process. The establishment of the reliability of
this technique will allow for synchronous collection of electrical and visual muscle activity
changes of a variety of muscles in the lumbopelvic-hip complex for both novice and experienced
raters.
Page 37
30
Appendix B: Additional Methods
Page 38
31
Table B1. IRB Approval Letter
Page 39
32
Table B1. IRB Approval Letter Cont.
Page 40
33
Table B2. Health History Form
Page 41
34
Table B3. Physical Activity Questionnaire
Page 42
35
Table B3. Physical Activity Questionnaire Cont.
Page 43
36
Table B4. Global Health Form
Page 44
37
Table B4. Global Health Form Cont.
Page 45
38
Table B5. Godin Questionnaire
Page 46
39
Table B5. Godin Questionnaire Cont.
Page 47
40
Table B6. Oswestry Disability Index
Page 48
41
Table B7. Physical Function Form
Page 49
42
Table B7. Physical Function Form Cont.
Page 50
43
Table B8. Disability Rating Scale For Low Back Pain
Page 51
44
Table B9. Tegner Activity Scale
Page 52
45
Complete Bibliography
1. Sarti MA, Monfort M, Fuster MA, Villaplana LA. Muscle activity in upper and lower
rectus abdominus during abdominal exercises. Arch Phys Med Rehabil. 1996;77(12):1293-
1297. doi:https://doi.org/10.1016/S0003-9993(96)90195-1
2. Belavý DL, Armbrecht G, Felsenberg D. Real-time ultrasound measures of lumbar erector
spinae and multifidus: reliability and comparison to magnetic resonance imaging. Physiol
Meas. 2015;36(11):2285. doi:10.1088/0967-3334/36/11/2285
3. Mangum LC, Sutherlin MA, Saliba SA, Hart JM. Reliability of Ultrasound Imaging
Measures of Transverse Abdominis and Lumbar Multifidus in Various Positions. PM&R.
2016;8(4):340-347. doi:10.1016/j.pmrj.2015.09.015
4. Mangum LC, Henderson K, Murray KP, Saliba SA. Ultrasound Assessment of the
Transverse Abdominis During Functional Movement. J Ultrasound Med. 37(5):1225-1231.
doi:10.1002/jum.14466
5. Teyhen DS, George SZ, Dugan JL, Williamson J, Neilson BD, Childs JD. Inter-Rater
Reliability of Ultrasound Imaging of the Trunk Musculature Among Novice Raters. J
Ultrasound Med. 2011;30(3):347-356.
6. DeLuca C. Surface Electromyography: Detection and Recording. Delsys Inc. 2002:1.
7. Partner JM SL Sutherlin, MA Acocello, S Saliba, SA Magrum, EM Hart. Changes in
Muscle Thickness After Exercise and Biofeedback in People with Low Back Pain. J Sport
Rehabil. 2014;23(4):307-318. doi:10.1123/JSR.2013-0057
8. Van, Khai, Hides JA. The Use of Real-Time Ultrasound Imaging for Biofeedback of
Lumbar Multifidus Muscle Contraction in Healthy Subjects. J Orthop Sports Phys Ther.
2006;36(12):920-925. doi:10.2519/jospt.2006.2304
9. Hermens HJ, Freriks B, Disselhorst-Klug C, Rau G. Development of recommendations for
SEMG sensors and sensor placement procedures. J Electromyogr Kinesiol. 2000;10(5):361-
374. doi:10.1016/S1050-6411(00)00027-4
10. Dieterich AV, Pickard CM, Strauss GR, Deshon LE, Gibson W, McKay J. Muscle
thickness measurements to estimate gluteus medius and minimus activity levels. Man Ther.
2014;19(5):453-460. doi:10.1016/j.math.2014.04.014
11. Dieterich AV, Pickard CM, Deshon LE, et al. M-mode ultrasound used to detect the onset
of deep muscle activity. J Electromyogr Kinesiol Off J Int Soc Electrophysiol Kinesiol.
2015;25(2):224-231.
Page 53
46
12. Ergai A, Cohen T, Sharp J, Wiegmann D, Gramopadhye A, Shappell S. Assessment of the
Human Factors Analysis and Classification System (HFACS): Intra-rater and inter-rater
reliability. Saf Sci. 2016;82:393-398. doi:10.1016/j.ssci.2015.09.028
13. Wallwork TL, Hides JA, Stanton WR. Intrarater and Interrater Reliability of Assessment of
Lumbar Multifidus Muscle Thickness Using Rehabilitative Ultrasound Imaging. J Orthop
Sports Phys Ther. 2007;37(10):608-612. doi:10.2519/jospt.2007.2418
14. Mannion AF, Pulkovski N, Toma V, Sprott H. Abdominal muscle size and symmetry at rest
and during abdominal hollowing exercises in healthy control subjects. J Anat.
2008;213(2):173-182. doi:10.1111/j.1469-7580.2008.00946.x
15. Koppenhaver SL. The Effect of Averaging Multiple Trials on Measurement Error During
Ultrasound Imaging of Transversus Abdominis and Lumbar Multifidus Muscles in
Individuals With Low Back Pain. J Orthop Sports Phys Ther. 2009;39(8):604-611.
doi:10.2519/jospt.2009.3088
16. Bolgla LA, Malone TR, Umberger BR, Uhl TL. COMPARISON OF HIP AND KNEE
STRENGTH AND NEUROMUSCULAR ACTIVITY IN SUBJECTS WITH AND
WITHOUT PATELLOFEMORAL PAIN SYNDROME. Int J Sports Phys Ther.
2011;6(4):285-296.
17. Koo TK, Li MY. A Guideline of Selecting and Reporting Intraclass Correlation
Coefficients for Reliability Research. J Chiropr Med. 2016;15(2):155-163.
doi:10.1016/j.jcm.2016.02.012
18. Blaak E. Gender differences in fat metabolism: Curr Opin Clin Nutr Metab Care.
2001;4(6):499-502. doi:10.1097/00075197-200111000-00006
19. Karastergiou K, Smith SR, Greenberg AS, Fried SK. Sex differences in human adipose
tissues - the biology of pear shape. Biol Sex Differ. 2012;3(1):13. doi:10.1186/2042-6410-3-
13
20. Rivera CE. Core and Lumbopelvic Stabilization in Runners. Phys Med Rehabil Clin N Am.
2016;27(1):319-337. doi:10.1016/j.pmr.2015.09.003
21. Danneels LA, Vanderstraeten GG, Cambier DC, Witvrouw EE, Stevens VK, De Cuyper
HJ. A functional subdivision of hip, abdominal, and back muscles during asymmetric
lifting. Spine. 2001;26(6):E114-121. doi:10.1097/00007632-200103150-00003
22. Robert A Laird1,5*, Jayce Gilbert2, Peter Kent3,4 and Jennifer L Keating1. Comparing
lumbo-pelvic kinematics in people with and without back pain: a systematic review and
meta-analysis. Laird Al BMC Musculoskelet Disord 2014 15229.
https://bmcmusculoskeletdisord.biomedcentral.com/track/pdf/10.1186/1471-2474-15-229.
Page 54
47
23. Gilmer GG, Washington JK, Dugas JR, Andrews JR, Oliver GD. The Role of
Lumbopelvic-Hip Complex Stability in Softball Throwing Mechanics. J Sport Rehabil.
2019;28(2):196-204. doi:10.1123/jsr.2017-0276
24. Majewski-Schrage T, Evans TA, Ragan B. Development of a core-stability model: a delphi
approach. J Sport Rehabil. 2014;23(2):95-106. doi:10.1123/jsr.2013-0001
25. Kibler WB, Press J, Sciascia A. The role of core stability in athletic function. Sports Med
Auckl NZ. 2006;36(3):189-198. doi:10.2165/00007256-200636030-00001
26. Huxel Bliven KC, Anderson BE. Core stability training for injury prevention. Sports
Health. 2013;5(6):514-522. doi:10.1177/1941738113481200
27. Okada T, Huxel KC, Nesser TW. Relationship between core stability, functional
movement, and performance. J Strength Cond Res. 2011;25(1):252-261.
doi:10.1519/JSC.0b013e3181b22b3e
28. Sharrock C, Cropper J, Mostad J, Johnson M, Malone T. A pilot study of core stability and
athletic performance: is there a relationship? Int J Sports Phys Ther. 2011;6(2):63-74.
29. De Blaiser C, Roosen P, Willems T, Danneels L, Bossche LV, De Ridder R. Is core
stability a risk factor for lower extremity injuries in an athletic population? A systematic
review. Phys Ther Sport. 2018;30:48-56. doi:10.1016/j.ptsp.2017.08.076
30. Willson JD, Dougherty CP, Ireland ML, Davis IM. Core stability and its relationship to
lower extremity function and injury. J Am Acad Orthop Surg. 2005;13(5):316-325.
doi:10.5435/00124635-200509000-00005
31. Barr KP, Griggs M, Cadby T. Lumbar Stabilization: Core Concepts and Current Literature,
Part 1. Am J Phys Med Rehabil. 2005;84(6):473-480.
doi:10.1097/01.phm.0000163709.70471.42
32. Suh JH, Kim H, Jung GP, Ko JY, Ryu JS. The effect of lumbar stabilization and walking
exercises on chronic low back pain: A randomized controlled trial. Medicine (Baltimore).
2019;98(26):e16173. doi:10.1097/MD.0000000000016173
33. Stanford ME. Effectiveness of Specific Lumbar Stabilization Exercises: A Single Case
Study. J Man Manip Ther. 2002;10(1):40-46. doi:10.1179/106698102792209549
34. Mosterman RM. [ROM, benchmark and risk adjustment in a private practice]. Tijdschr
Voor Psychiatr. 2020;62(1):27-36.
35. Berko NS, Le JN, Thornhill BA, et al. Incorporation of musculoskeletal ultrasound training
into the radiology core curriculum. Skeletal Radiol. 2018;47(7):911-912.
doi:10.1007/s00256-018-2955-z
Page 55
48
36. Brink RC, Wijdicks SPJ, Tromp IN, et al. A reliability and validity study for different
coronal angles using ultrasound imaging in adolescent idiopathic scoliosis. Spine J Off J
North Am Spine Soc. 2018;18(6):979-985. doi:10.1016/j.spinee.2017.10.012
37. Mc Auliffe S, Mc Creesh K, Purtill H, O’Sullivan K. A systematic review of the reliability
of diagnostic ultrasound imaging in measuring tendon size: Is the error clinically
acceptable? Phys Ther Sport Off J Assoc Chart Physiother Sports Med. 2017;26:52-63.
doi:10.1016/j.ptsp.2016.12.002
38. Pirri C, Todros S, Fede C, et al. Inter‐rater reliability and variability of ultrasound
measurements of abdominal muscles and fasciae thickness. Clin Anat. 2019;32(7):948-960.
doi:10.1002/ca.23435
39. Linek P, Saulicz E, Wolny T, Myśliwiec A. Intra-rater Reliability of B-Mode Ultrasound
Imaging of the Abdominal Muscles in Healthy Adolescents During the Active Straight Leg
Raise Test. PM&R. 2015;7(1):53-59. doi:10.1016/j.pmrj.2014.07.007
40. Whittaker JL, Emery CA. Sonographic Measures of the Gluteus Medius, Gluteus Minimus,
and Vastus Medialis Muscles. J Orthop Sports Phys Ther. 2014;44(8):627-632.
doi:10.2519/jospt.2014.5315
41. Montoya J, Stawicki SP, Evans DC, et al. From FAST to E-FAST: an overview of the
evolution of ultrasound-based traumatic injury assessment. Eur J Trauma Emerg Surg Off
Publ Eur Trauma Soc. 2016;42(2):119-126. doi:10.1007/s00068-015-0512-1
42. Aguilar L, Wong J, Steinman DA, Cobbold RSC. FAMUS II: A Fast and Mechanistic
Ultrasound Simulator Using an Impulse Response Approach. IEEE Trans Ultrason
Ferroelectr Freq Control. 2017;64(2):362-373. doi:10.1109/TUFFC.2016.2632706
43. Errico C, Pierre J, Pezet S, et al. Ultrafast ultrasound localization microscopy for deep
super-resolution vascular imaging. Nature. 2015;527(7579):499-502.
doi:10.1038/nature16066
44. Magalhães L, Martins SRP, Nogué R. The role of point-of-care ultrasound in the diagnosis
and management of necrotizing soft tissue infections. Ultrasound J. 2020;12(1):3.
doi:10.1186/s13089-020-0153-4
45. Sippel S, Muruganandan K, Levine A, Shah S. Review article: Use of ultrasound in the
developing world. Int J Emerg Med. 2011;4(1):72. doi:10.1186/1865-1380-4-72
46. Jaspers N, Holzapfel B, Kasper P. [Abdominal ultrasound in emergency and critical care
medicine]. Med Klin Intensivmed Notfallmedizin. 2019;114(6):509-518.
doi:10.1007/s00063-019-0551-1
Page 56
49
47. Shokoohi H, Raymond A, Fleming K, et al. Assessment of Point-of-Care Ultrasound
Training for Clinical Educators in Malawi, Tanzania and Uganda. Ultrasound Med Biol.
2019;45(6):1351-1357. doi:10.1016/j.ultrasmedbio.2019.01.019
48. Dieterich AV, Deshon L, Pickard CM, Strauss GR, McKay J. Separate assessment of
gluteus medius and minimus: B-mode or M-mode ultrasound? Physiother Theory Pract.
2014;30(6):438-443. doi:10.3109/09593985.2014.890261
49. McKay GFM, Weerasinghe A. Can we successfully teach novice junior doctors basic
interventional ultrasound in a single focused training session? Postgrad Med J.
2018;94(1111):259-262. doi:10.1136/postgradmedj-2018-135590
50. Uya A, Spear D, Patel K, Okada P, Sheeran P, McCreight A. Can Novice Sonographers
Accurately Locate an Endotracheal Tube With a Saline-filled Cuff in a Cadaver Model? A
Pilot Study: NOVICE SONOGRAPHERS USING SALINE-FILLED ETT CUFF. Acad
Emerg Med. 2012;19(3):361-364. doi:10.1111/j.1553-2712.2012.01306.x
51. Østergaard ML, Rue Nielsen K, Albrecht-Beste E, Kjær Ersbøll A, Konge L, Bachmann
Nielsen M. Simulator training improves ultrasound scanning performance on patients: a
randomized controlled trial. Eur Radiol. 2019;29(6):3210-3218. doi:10.1007/s00330-018-
5923-z
52. Chowdhury A, Punj J, Pandey R, Darlong V, Sinha R, Bhoi D. Ultrasound is a reliable and
faster tool for confirmation of endotracheal intubation compared to chest auscultation and
capnography when performed by novice anaesthesia residents - A prospective controlled
clinical trial. Saudi J Anaesth. 2020;14(1):15. doi:10.4103/sja.SJA_180_19
53. IEEE Engineering in Medicine and Biology Society, Annual International Conference,
IEEE Engineering in Medicine and Biology Society, Institute of Electrical and Electronics
Engineers. 2019 41st Annual International Conference of the IEEE Engineering in
Medicine and Biology Society (EMBC): Biomedical Engineering Ranging from Wellness to
Intensive Care : 41st EMB Conference 2019 : July 23-27, Berlin.; 2019.
https://ieeexplore.ieee.org/servlet/opac?punumber=8844528. Accessed February 3, 2020.
54. Rubin DI. Needle electromyography: basic concepts and patterns of abnormalities. Neurol
Clin. 2012;30(2):429-456. doi:10.1016/j.ncl.2011.12.009
55. Rubin DI. Needle electromyography: Basic concepts. Handb Clin Neurol. 2019;160:243-
256. doi:10.1016/B978-0-444-64032-1.00016-3
56. Watanabe K, Akima H. Validity of surface electromyography for vastus intermedius muscle
assessed by needle electromyography. J Neurosci Methods. 2011;198(2):332-335.
doi:10.1016/j.jneumeth.2011.03.014
Page 57
50
57. Zwarts MJ. Evaluation of the estimation of muscle fiber conduction velocity. Surface
versus needle method. Electroencephalogr Clin Neurophysiol. 1989;73(6):544-548.
doi:10.1016/0013-4694(89)90263-0
58. Botter A, Carbonaro M, Vieira TM, Hodson-Tole E. Identification of muscle fasciculations
from surface EMG: comparison with ultrasound-based detection *. In: 2019 41st Annual
International Conference of the IEEE Engineering in Medicine and Biology Society
(EMBC). Berlin, Germany: IEEE; 2019:5117-5120. doi:10.1109/EMBC.2019.8857873
59. International Conference on Human System Interaction, Institute of Electrical and
Electronics Engineers, IEEE Industrial Electronics Society, University of Portsmouth.
Proceedings, 2016 9th International Conference on Human System Interactions (HSI):
Portland Building, University of Portsmouth, Portsmouth, United Kingdom, 06-08 July,
2016.; 2016. http://ieeexplore.ieee.org/servlet/opac?punumber=7523844. Accessed
February 3, 2020.
60. Kim B-J, Lee S-K. Effects of three spinal stabilization techniques on activation and
thickness of abdominal muscle. J Exerc Rehabil. 2017;13(2):206-209.
doi:10.12965/jer.1734900.450
61. Marchetti PH, Kohn AF, Duarte M. Selective activation of the rectus abdominis muscle
during low-intensity and fatiguing tasks. J Sports Sci Med. 2011;10(2):322-327.
62. Abuín-Porras V, Maldonado-Tello P, de la Cueva-Reguera M, et al. Comparison of Lateral
Abdominal Musculature Activation during Expiration with an Expiratory Flow Control
Device Versus the Abdominal Drawing-in Maneuver in Healthy Women: A Cross-
Sectional Observational Pilot Study. Medicina (Mex). 2020;56(2):84.
doi:10.3390/medicina56020084
63. Gilfeather D, Norte G, Ingersoll CD, Glaviano NR. Central Activation Ratio Is a Reliable
Measure for Gluteal Neuromuscular Function. J Sport Rehabil. 2019:1-7.
doi:10.1123/jsr.2019-0243
64. Qinghua Huang, Yongping Zheng, Xin Chen, Jun Shi. Development of a Synchronized
System for Continuous Acquisition and Analysis of Ultrasound Joint Angle, and EMG. In:
2005 IEEE Engineering in Medicine and Biology 27th Annual Conference. Shanghai,
China: IEEE; 2005:989-992. doi:10.1109/IEMBS.2005.1616583
65. Mostofi E, Chahal B, Zonoobi D, et al. Reliability of 2D and 3D ultrasound for infant hip
dysplasia in the hands of novice users. Eur Radiol. 2019;29(3):1489-1495.
doi:10.1007/s00330-018-5699-1
66. König N, Cassel M, Intziegianni K, Mayer F. Inter-rater reliability and measurement error
of sonographic muscle architecture assessments. J Ultrasound Med Off J Am Inst
Ultrasound Med. 2014;33(5):769-777. doi:10.7863/ultra.33.5.769
Page 58
51
67. Scarlata S, Mancini D, Laudisio A, Benigni A, Antonelli Incalzi R. Reproducibility and
Clinical Correlates of Supine Diaphragmatic Motion Measured by M-Mode
Ultrasonography in Healthy Volunteers. Respiration. 2018;96(3):259-266.
doi:10.1159/000489229
68. Marques CJ, Martin T, Fiedler F, et al. Intra- and Inter-rater Reliability of Navigated
Ultrasound in the Assessment of Pelvic Tilt in Symptom-Free Young Adults. J Ultrasound
Med Off J Am Inst Ultrasound Med. 2018;37(10):2333-2342. doi:10.1002/jum.14581
69. Hougs Kjær B, Ellegaard K, Wieland I, Warming S, Juul-Kristensen B. Intra-rater and
inter-rater reliability of the standardized ultrasound protocol for assessing subacromial
structures. Physiother Theory Pract. 2017;33(5):398-409.
doi:10.1080/09593985.2017.1318419
70. Gómez-Tamayo JC, Puerta-Guarín JI, Rojas-Camejo CM, Caicedo JP, Calvache JA. Inter-
rater and intra-rater reliability of the airway diameter measured by sonography. J
Ultrasound. 2018;21(1):35-40. doi:10.1007/s40477-017-0276-z
71. Hosseinifar M, Akbari A, Ghiasi F. Intra-Rater Reliability of Rehabilitative Ultrasound
Imaging for Multifidus Muscles Thickness and Cross Section Area in Healthy Subjects.
Glob J Health Sci. 2015;7(6):354-361. doi:10.5539/gjhs.v7n6p354