Ultrasound Evaluation of the Effect of Osteopathic Manipulative Treatment on Sacral Base Asymmetry
Phase: NA
Conditions: Manipulation, Osteopathic
Sponsor: A.T. Still University of Health Sciences

 
 
 
 
 
 
 
 
 
 
 
Ultrasonographic Evaluation of the Effect of Osteopathic Manipulative 
Treatment on Sacral Base Asymmetry 
Karen T. Snider, DO; Crystal L. Redman, DO; Christopher R. Edwards, DO; Shalini Bhatia, MS; Tatyana 
Kondrashova, MD, PhD 
NCT02820701 
Updated January 8, 2019 
 
 
 

Ultrasound Evaluation of the Effect of Osteopathic Manipulative Treatment on Sacral Base Asymmetry   
A. Specific Aims   
The long term objective of this study is to establish objective measurements of musculoskeletal changes 
that occur in response to osteopathic manipulative treatment (OMT). Many patients who suffer from low back 
pain (LBP) receive OMT to the lumbar, pelvic, sacral, and lower extremity body regions that helps resolve or 
manage their pain. The indication for OMT in a patient suffering from LBP is the presence of somatic 
dysfunction found during the physical examination. Somatic dysfunction is diagnosed when one or more of the 
following physical findings are present: tenderness, asymmetry, restricted range of motion, and tissue texture 
abnormalities. OMT is performed to specifically target these physical findings, after which the patient is 
reassessed for a reduction or resolution of the findings. In the clinical setting the assessment and reassessment 
of somatic dysfunction is performed using palpatory examination. Because palpatory findings commonly 
demonstrate poor interexaminer reliability, the proposed study will use ultrasound to establish pre- and 
postOMT musculoskeletal measurements of the relative asymmetry between the participants’ pelvic and sacral 
bony landmarks. The investigators will use a control group to compare the changes in the pre and post OMT 
measurements to participants who have not received OMT. If ultrasonography is able to detect a significant 
change in the relative asymmetry between the pelvis and sacrum, then ultrasound may be useful for assessing 
and quantifying outcomes for OMT in a variety of body regions such as spine, shoulders, and knees. To 
determine if ultrasound is a reliable objective measure to assess OMT outcomes in LBP patients the following 
specific aims are proposed:  
• 
Determine if ultrasound measurements of sacral landmarks are stable over 30 minutes in untreated 
participants.  
• 
Determine the extent to which OMT affects the relative asymmetry between the pelvic and sacral 
landmarks as measured by ultrasonography.  
• 
Determine if ultrasound measurements of sacral base asymmetry agree with palpatory assessment.  
B. Background and Significance   
Numerous studies have demonstrated the clinical efficacy of manual medicine techniques such as OMT 
in the care of patients with LBP.1-4  The clinical efficacy is indicated by the reduction of the patient’s pain.  But 
the mechanisms of how these techniques work remains unclear. Clinically, patients are reassessed after OMT 
for changes in pain level, tenderness, tissue texture abnormalities, restricted range of motion and asymmetry. 
While palpatory assessment of somatic dysfunction before and after OMT is useful clinically, it is not reliable 
for use as pre- and post-treatment outcome measures because of generally poor interexaminer reliability.  
Individual examiners are often not accurate in their identification of bony landmarks5-7 and therefore any 
measurements derived from those findings would not be valid. Therefore the use of objective measurements 
to assess pre- and post-treatment outcomes is desirable.   
Most studies objectively assessing somatic dysfunction before and after manual medicine techniques 
have evaluated changes in tenderness using algometers to measure pressure pain thresholds (PPT). These 
studies have overwhelmingly found that manual medicine increases PPT, meaning that after manipulation the 
tissues tolerate more pressure before inducing pain.8-10  However, this finding may be an indirect effect of the 
technique rather than primary mechanism of action.  Other studies have demonstrated that manual medicine 
techniques induce changes in serum biomarker levels8, 11-15 and muscle activation16, 17 which also may be an 
indirect effect. A potential mechanism for OMT inducing these physiologic responses is the change in bony 
symmetry around a dysfunctional articulation.  The change in symmetry would affect joint range of motion and 
muscular and ligamentous balance which in turn can affect the neurological proprioceptive responses and 
thus, a wide variety of processes.18  Childs et al19 found that improvements in lumbopelvic symmetry following 
spinal manipulation were associated with pain reduction, however lumbopelvic symmetry was assessed using 

palpation.  For a more in depth understanding of these mechanisms, an objective measurement of symmetry is 
needed.   
The choices for objective measurements of bony landmarks include plain film radiography, computed 
tomography (CT), magnetic resonance imaging (MRI), and ultrasonography (US).  While all of these studies are 
useful for obtaining images of bony landmarks, radiography and CT expose study participants to potentially 
harmful ionizing radiation and MRI is very expensive.  Therefore, US, which is inexpensive and radiation-free, is 
a good choice for obtaining objective outcome measures. Several studies have used ultrasound measurements 
as outcome measures in manual medicine studies. Brenner et al16 measured the lumbar multifidus muscle 
thickness (LMMT) pre and post contraction in a single person before and after spinal manipulation and found 
that spinal manipulation greatly increased the change in LMMT between pre and post contraction, suggesting 
that the intervention marked improved ability of the muscle to contract. Shaw et al20 used ultrasonography to 
assess lumbar vertebral transverse process asymmetry before and after OMT and found that the OMT 
significantly improved the symmetry.  Therefore, the proposed study will investigate the use of 
ultrasonography to assess changes in lumbopelvic bony symmetry that occur in response to OMT.  
  
A Reliability and Reproducibility of Ultrasound Measurements in the Lumbosacral Region  
Real-time ultrasound imaging is well established as a safe and feasible method to evaluate 
musculoskeletal structures. As with any imaging modality, reliability of ultrasound measurements is an 
important characteristic that reflects the degree to which repeated measurements provide similar results. 
Demonstrating acceptable reliability is essential for any kind of measurement and for making valid assumptions 
based on the data. Multiple studies have found that ultrasound assessment of lumbosacral bony landmarks is 
as reliable as CT or MRI. Liu et al21 compared US to CT measurements of facet joint height and width and found 
no significant difference. Chleboun et al22 compared US to MRI measurements of distance between lumbar 
spinous processes in neutral, flexion and extension, and found no significant difference in the measurements 
obtained  by the two types of studies. In a recent study we evaluated the depth of the sacral sulcus by 
measuring the depth of posterior superior iliac spine (PSIS)  and depth of the sacral base using ultrasonography 
through real-time and direct visualization and evaluation of above-mentioned structures.23 This study yielded 
consistent results establishing sacral base position using US.  
Sacral Base Asymmetry  
Several studies have demonstrated that patients with LBP have a significantly greater incidence and  
severity of somatic dysfunction in the lumbar, pelvic, and sacral body regions than people without LBP.24-26  
Sacral somatic dysfunction is diagnosed, in part, by the presence of asymmetry of the sacral bases. The sacral 
bases are the superior portions of the sacrum located medial to the sacroiliac joints (Figure 1A). Palpatory 
assessment of sacral base asymmetry is performed by comparing the relative anterior or posterior position of 
each sacral base and by determining the relative depth of each sacral sulcus (deep or shallow) (Figure 1B).27 
These findings, along with information regarding the symmetry of other sacral landmarks, tenderness, tissue 
texture abnormalities, and restricted range of motion, are used to determine what types of OMT techniques 
will be used to treat the sacral somatic dysfunction. The sacral bases are ideal for objective measurement of 
landmarks because their close proximity to the PSIS of the iliac bones allows for a comparison of two bony 
landmarks on either side of the sacroiliac joint. Sacral base asymmetry can also be measured objectively with 
US, which allows for objective measurements that can be used to assess the effect of OMT on sacral base 
asymmetry.  
  
C. Purpose Statement and Hypotheses  
The objective of the proposed study is to quantify the change in sacral base asymmetry as measured by 
ultrasonography before and after OMT. The proposed study will utilize a control group to determine the 
stability of the sacral measurements and compare those findings to a treatment group that will receive OMT to 

specifically address sacral somatic dysfunction as identified clinically. The proposed study will also compare the 
clinical palpatory assessment of sacral base asymmetry to the ultrasound measurements. Since the primary 
aim of this study is to assess the effect of OMT on sacral base asymmetry, the investigators will recruit 
participants with a recent history of LBP to ensure a high likelihood that the participants will have sacral  
 
Figure 1. (A) Posterior view of the pelvis. The sacral base is the posterior superior surface of the sacrum 
divided into the right sacral base and the left sacral base. Posterior superior iliac spines (PSIS) are tubercles 
that project posteriorly from the posteromedial portion of the iliac bones on either side. (B) Superior view 
of the posterior pelvis. Sacral bases are traditionally palpated to assess for asymmetry by determining the 
relative anterior or posterior positioning of each sacral base and the relative depth of each sacral sulcus 
(deep or shallow).  
somatic dysfunction which would include sacral base asymmetry. This assumption is based on several studies 
that have found that people with LBP have a significantly greater incidence and severity of somatic dysfunction 
in the lumbar, pelvic and sacral regions than people without LBP.24-26   
  
D. Research Design and Methods   
This prospective, randomized, controlled trial is proposed to investigate the effect of OMT on sacral 
base asymmetry as assessed by US. The study will be conducted over the course of two months. Forty men and 
women ages 20 to 55 years with at least one or more episodes of LBP in the past two weeks will be randomly 
assigned into one of two groups – control or OMT groups. Twenty participants will be assigned to each group. 
The study will begin recruitment in July 2016 pending institutional review board approval. Participants will be 
recruited from the surrounding Kirksville area. Individuals with prior spinal surgery, fractures, or known 
congenital anomalies of the lumbar vertebra and sacrum will be excluded. Individuals who cannot lie prone for 
30 minutes, or who cannot tolerate OMT will be excluded. Subjects will be randomly assigned into two groups, 
control or OMT using a random number generator. Males and females will be randomized separately to ensure 
equal distribution into the two study groups. Demographics including sex, age, and body mass index (BMI) will 
be collected on all participants.  
All participants will receive an initial palpatory assessment of the sacral base asymmetry and then an 
initial ultrasound evaluation of sacral base asymmetry. After the ultrasound assessment, the control group will 
wait in another room for approximately 30 minutes. Participants in the OMT group will receive OMT to address 
sacral base asymmetry after the initial ultrasound assessment. Following the treatment period for the OMT 
group, all subjects will receive a second ultrasound assessment of sacral base asymmetry. The 
ultrasonographer will be blinded on whether the subject received an OMT or not.  
  
1 B .  
1 A 

Palpatory Assessment  
Prior to the initial ultrasound evaluation all participants will receive a palpatory assessment of the 
relative position of the sacral bases (anterior or posterior) and the relative depth of the sacral sulci (deep or 
shallow) as illustrated in Figure 1B. For this assessment, the participant will be in the prone position. The sacral 
bases will be palpated at a point just slightly superior and medial to the PSIS midpoint. The sacral base that is 
further forward toward the front of the participant will be designated as anterior. The sacral base that is 
positioned more toward the back of the participant will be designated as posterior. Sacral bases that are equal 
in the coronal plane, with neither side more anterior or posterior will be considered level. The sacral sulcus 
depth will be palpated as the relative distance from a point just slightly superior and medial to the PSIS 
midpoint down to the sacral base.  The sacral sulcus that has the greater depth from the PSIS to the sacral base 
will be designated as deep. The sacral sulcus that has the lesser depth from the PSIS to the sacral base will be 
designated as shallow. After both the palpatory assessment of sacral base asymmetry and the initial ultrasound 
assessment have been performed, the findings will be compared.   
  
Ultrasound Assessment  
All participants will receive two ultrasound assessments evaluating sacral base asymmetry: an initial 
ultrasound assessment after the palpatory assessment, then a second ultrasound assessment after the 
treatment period. Ultrasound assessment will include the ultrasound imaging of the participants in the prone 
position  during which an experienced ultrasonographer, who is blinded to the participant group assignment, 
will measure the depth from the skin to the PSIS (SPSIS) and the depth from the skin to the sacral sulcus base 
(SSB) on the right and left sides before and after the treatment period as illustrated in Figure 2.  For each 
measurement, the ultrasound transducer will be placed directly over the landmark and consistent contact 
pressure will be used. The skin surface over the measurement locations will be marked with waterproof ink to 
ensure consistency in measurement locations between the first and second ultrasound assessments. The sacral 
sulcus depth (SSD) will be calculated from the two ultrasound measurements as (SSD) = (SSB) - (SPSIS).  The 
measurements will be compared before and after the intervention period. For comparison of the palpatory 
assessment of sacral base asymmetry to the ultrasound measurements, the larger SSB measurement will be 
considered the anterior sacral base, the smaller SSB will be considered the posterior sacral base, the greater 
SSD will be considered the deep sacral sulcus, and the lesser SSD will be considered the shallow sacral sulcus.  
 
  
 Figure 2. (A) Sacral base depth (SBD) will be measured as the distance between the skin and the sacral base  
position. Posterior superior iliac spine (PSIS) depth will be measured as the distance between the skin and  the 
PSIS (SPSIS). Sacral sulcus depth (SSD) is calculated as (SSB) – (SPSIS) = (SSD). (B) Ultrasound image  illustrating 
the measured distance between the skin and the sacral base position, the distance between the  skin, and the 
PSIS and the SSD.  
  
2 B.  
2 A 

OMT Treatment  
The OMT treatment will begin with a brief physical examination to identify somatic dysfunction in the 
lumbar, pelvic, sacral, and lower extremity body regions that the treating physician judges to be relevant to the 
individual participant's sacral asymmetry. OMT will be performed with the specific goal of improving sacral 
asymmetry by treating the sacrum and the surrounding regions (lumbar, pelvis, and lower extremities). The 
types of OMT techniques used will include muscle energy, articular, or high velocity-low amplitude (HVLA) as 
indicated by the physical findings and will be at the discretion of the treating physician. Additional techniques 
such as Still, counterstrain, facilitated positional release, balanced ligamentous tension, and cranial techniques 
may also be used at the discretion of the treating physician with the total treatment time not to exceed 20 
minutes. To encourage participation in the proposed study, participants who are assigned to the control group 
will have an opportunity to receive OMT after the second ultrasound assessment.   
  
Preliminary Data  
As part of a study investigating the feasibility of integrating ultrasound into an OMM curriculum, 247 
students assessed the sacral base asymmetry of another student using US.28 They measured SPSIS and SSB on 
the right and left sides, then calculated the SSD as (SSB) - (SPSIS)= (SSD). The results are shown in Table 1. The 
calculated SSD demonstrated a wide range of depths (0 to 4.03 cm). The sacral sulcus depth difference (SSDD) 
between the right and left sides also demonstrated a wide range (-2.01 to 2.52 cm). Negative SSDD values 
indicated that the right sacral sulcus depth was shallower than the left and positive values indicate that the 
right sacral sulcus was deeper than the left, although these differences were not statistically significant.  
  
Table 1: Student measurements of sacral base landmarks (N=247).   
  
  
Left SPSIS  
(cm)  
Left SSB 
(cm)  
Right SPSIS  
(cm)  
Right SSB  
(cm)  
Left SSD  
(cm)  
Right SSD  
(cm)  
SSDD  
(cm)  
Maximum  
6.33  
8.24  
4.94  
8.29  
3.65  
4.03  
2.52  
Minimum  
0.49  
1.48  
0.37  
1.67  
0.00  
0.33  
-2.01  
Average  
1.72  
3.61  
1.64  
3.62  
1.88  
1.98  
0.10  
STDev  
0.81  
0.96  
0.77  
0.97  
0.59  
0.63  
0.57  
Abbreviations: SPSIS, distance from skin to posterior superior iliac spine (PSIS); SSB, distance from skin to sacral 
base (SSB); SSD, sacral sulci depth calculated as (SSB) - (SPSIS) = (SSD); SSDD, sacral sulcus depth difference 
between right and left SSD.  
  
Data analysis  
Power calculations performed on preliminary SSDD data suggested that recruiting 38 participants 
would allow us to detect mean difference of ±0.5 cm in the two treatment groups at pre-post treatment 
analysis at 0.05 significance level with 80% power. We plan to recruit 40 participants total (20 in each group). 
While the students, who collected the preliminary data, were not expert ultrasonographers, the quantity of 
data allows for an estimation of the likely range of measurements that will be seen in the proposed study. 
Descriptive statistics such as means, ranges, and standard deviations (SD) for continuous variables and 
frequency and percent will be used to summarize the categorical data. Two sample t-tests will be used to 
compare mean age and BMI across groups.     
  
Correlations between BMI and US measurements will be calculated for each landmark (SPSIS, SBP, 
SSD). Absolute asymmetry between left and right landmark measurements will be calculated as follows:  
  

absolute asymmetry = │landmarkleft− landmarkright│  
  
To determine if absolute asymmetry increased, decreased, or stayed the same after intervention,  
direction of change in asymmetry will be calculated as follows:  
  
direction of change in asymmetry = │2nd US landmarkleft – 2nd US landmarkright│>, <, or  
=│1st US landmarkleft – 1st US landmarkright│  
  
To account for total change in measurements at both left and right landmarks between the first and 
second US measurements, total change in asymmetry between first and second US assessments will be 
calculated as follows:  
  
total change in asymmetry = │ (1st US landmarkleft − 1st US landmarkright) − (2nd US landmarkleft − 2nd US 
landmarkright) │  
  
The Fisher exact test is to be used to test associations between group and direction of change in 
asymmetry at each landmark. Multiple linear regression models will be built to compare mean absolute 
asymmetry for each landmark measured during the first US assessment between groups while controlling for 
demographic characteristics, date of last pain, and frequency of pain. Similar multiple linear regression models 
will be built to compare mean total change in asymmetry from first to second US assessment between groups 
for each landmark between groups.  
  
Mean absolute asymmetry at the first and second US assessments and mean total change in 
asymmetry for seated control and OMT groups will be compared using a 2-sample t test. To compare 
qualitative palpatory assessment of SBP and SSD with quantitative US measurements, US measurement of 
landmark position will be first converted to a qualitative assessment as follows:  
  
▪ right anterior SBP or deep SSD = right US measurement > left US measurement  
▪ right posterior SBP or shallow SSD = right US measurement < left landmark measurement  
▪ equal SBP or SSD = right US measurement = left US measurement  
  
To compare agreement between qualitative palpatory and US assessments of SBP and SSD, κ and 
associated 95% CIs will be calculated. Values less than or equal to 0 indicated no agreement; 0.01 to 0.20, none 
to slight; 0.21 to 0.40, fair; 0.41 to 0.60, moderate; 0.61 to 0.80, substantial; and 0.81 to 1.00, almost perfect 
agreement.  
  
To determine if US localization of landmarks at the sacral base was reliable, intraclass correlation 
coefficients (ICC) and associated 95% CIs will be calculated for US measurements from the first to second US 
assessment for each landmark. For ICC, 0.7 to 0.8 was considered good; 0.8 to 0.9, very good; and 0.9 to 1.0, 
excellent. P≤.05 was considered significant. Data analysis will be performed using SAS statistical software 
version 9.4 (SAS Institute, Inc.).  
  
Potential Limitations  
The primary limitation to the ultrasound measurements is maintaining consistency in location of the 
initial and second ultrasound measurements. This limitation will be addressed by using a single, 
highlyexperienced ultrasound examiner. To ensure that the ultrasound measurements are made at the exact 
same locations during the initial and second ultrasound assessments on an individual participant, the 

ultrasound examiner will mark the skin overlying the measurement locations using waterproof ink. The use of 
multiple types of OMT techniques in this study may introduce some potential treatment bias; however 
multiple techniques are typically used in on a single patient in a clinical setting.  Future studies could assess the 
efficacy of individual techniques to improve asymmetry. The control group will be used to evaluate whether 
the ultrasound sacral measurements are stable over a period of time. To determine if participant sex, age, or 
BMI affect the reliability of the ultrasound or palpatory assessments, additional analyses may be run to assess 
if participant sex, age, or BMI confound the percent agreement between the two assessments.  
  
E. References  
1. 
Licciardone JC, Kearns CM, Minotti DE. Outcomes of osteopathic manual treatment for chronic low 
back pain according to baseline pain severity: results from the OSTEOPATHIC Trial. Man Ther. 
2013;18(6):533-540.  
2. 
Schwerla F, Rother K, Rother D, Ruetz M, Resch KL. Osteopathic Manipulative Therapy in Women With 
Postpartum Low Back Pain and Disability: A Pragmatic Randomized Controlled Trial. J Am Osteopath 
Assoc. 2015;115(7):416-425.  
3. 
Tozzi P, Bongiorno D, Vitturini C. Fascial release effects on patients with non-specific cervical or lumbar 
pain. J Bodyw Mov Ther. 2011;15(4):405-416.  
4. 
Xia T, Long CR, Gudavalli MR, et al. Similar Effects of Thrust and Non-Thrust Spinal Manipulation Found 
in Adults With Subacute and Chronic Low Back Pain - A Controlled Trial with Adaptive Allocation. Spine 
(Phila Pa 1976). 2015. [Epub ahead of print].  
5. 
Kilby J, Heneghan NR, Maybury M. Manual palpation of lumbo-pelvic landmarks: a validity study. Man 
Ther. 2012;17(3):259-262.  
6. 
Kim HW, Ko YJ, Rhee WI, et al. Interexaminer reliability and accuracy of posterior superior iliac spine 
and iliac crest palpation for spinal level estimations. J Manipulative Physiol Ther. 2007;30(5):386-389.  
7. 
Snider KT, Snider EJ, Degenhardt BF, Johnson JC, Kribs JW. Palpatory accuracy of lumbar spinous 
processes using multiple bony landmarks. J Manipulative Physiol Ther. 2011;34(5):306-313.  
8. 
Molina-Ortega F, Lomas-Vega R, Hita-Contreras F, et al. Immediate effects of spinal manipulation on 
nitric oxide, substance P and pain perception. Man Ther. 2014;19(5):411-417.  
9. 
Savva C, Giakas G, Efstathiou M. The role of the descending inhibitory pain mechanism in 
musculoskeletal pain following high-velocity, low amplitude thrust manipulation: a review of the 
literature. J Back Musculoskelet Rehabil. 2014;27(4):377-382.  
10. 
Willett E, Hebron C, Krouwel O. The initial effects of different rates of lumbar mobilisations on pressure 
pain thresholds in asymptomatic subjects. Man Ther. 2010;15(2):173-178.  
11. 
Degenhardt BF, Darmani NA, Johnson JC, et al. Role of osteopathic manipulative treatment in altering 
pain biomarkers: a pilot study. J Am Osteopath Assoc. 2007;107(9):387-400.  
12. 
Degenhardt BF, Johnson JC, Fossum C, Andicochea CT, Stuart MK. Changes in Cytokines, Sensory Tests, 
and Self-Reported Pain Levels After Manual Treatment of Low Back Pain. J Spinal Disord Tech. 2014. 
[Epub ahead of print].  
13. 
Licciardone JC, Kearns CM, Hodge LM, Bergamini MV. Associations of cytokine concentrations with key 
osteopathic lesions and clinical outcomes in patients with nonspecific chronic low back pain: results 
from the OSTEOPATHIC Trial. J Am Osteopath Assoc. 2012;112(9):596-605.  
14. 
McPartland JM, Giuffrida A, King J, Skinner E, Scotter J, Musty RE. Cannabimimetic effects of 
osteopathic manipulative treatment. J Am Osteopath Assoc. 2005;105(6):283-291.  
15. 
Plaza-Manzano G, Molina-Ortega F, Lomas-Vega R, Martinez-Amat A, Achalandabaso A, Hita-Contreras 
F. Changes in biochemical markers of pain perception and stress response after spinal manipulation. J 
Orthop Sports Phys Ther. 2014;44(4):231-239.  

16. 
Brenner AK, Gill NW, Buscema CJ, Kiesel K. Improved activation of lumbar multifidus following spinal 
manipulation: a case report applying rehabilitative ultrasound imaging. J Orthop Sports Phys Ther. 
2007;37(10):613-619.  
17. 
Grindstaff TL, Hertel J, Beazell JR, Magrum EM, Ingersoll CD. Effects of lumbopelvic joint manipulation 
on quadriceps activation and strength in healthy individuals. Man Ther. 2009;14(4):415-420.  
18. 
Wong CK. Strain counterstrain: current concepts and clinical evidence. Man Ther. 2012;17(1):2-8.  
19. 
Childs JD, Piva SR, Erhard RE. Immediate improvements in side-to-side weight bearing and iliac crest 
symmetry after manipulation in patients with low back pain. J Manipulative Physiol Ther. 
2004;27(5):306-313.  
20. 
Shaw KA, Dougherty JJ, Treffer KD, Glaros AG. Establishing the content validity of palpatory 
examination for the assessment of the lumbar spine using ultrasonography: a pilot study [erratum 
appears in J Am Osteopath Assoc. 2013;113(6):449]. J Am Osteopath Assoc. 2012;112(12):775-782.  
21. 
Liu D, Huang Y, Tian D, Yin J. Quantitative ultrasound assessment of the facet joint in the lumbar spine: 
a feasibility study. Ultrasound Med Biol. 2015;41(5):1226-1232.  
22. 
Chleboun GS, Amway MJ, Hill JG, Root KJ, Murray HC, Sergeev AV. Measurement of segmental lumbar 
spine flexion and extension using ultrasound imaging. J Orthop Sports Phys Ther. 2012;42(10):880-885.  
23. 
Lockwood MD, Kondrashova T, Johnson JC. Feasibility of Using Ultrasonography to Establish 
Relationships Among Sacral Base Position, Sacral Sulcus Depth, Body Mass Index, and Sex. J Am 
Osteopath Assoc. 2015;115(11):648-653.  
24. 
Licciardone JC, Kearns CM. Somatic dysfunction and its association with chronic low back pain, 
backspecific functioning, and general health: results from the OSTEOPATHIC Trial. J Am Osteopath 
Assoc. 2012;112(7):420-428.  
25. 
Snider KT, Johnson JC, Degenhardt BF, Snider EJ, Burton DC. Association of low back pain, somatic 
dysfunction, and lumbar bone mineral density: reproducibility of findings. J Am Osteopath Assoc. 
2014;114(5):356-367.  
26. 
Snider KT, Johnson JC, Snider EJ, Degenhardt BF. Increased incidence and severity of somatic 
dysfunction in subjects with chronic low back pain. J Am Osteopath Assoc. 2008;108(8):372-378.  
27. 
Heinking KP, Kappler RE. Pelvis and sacrum. In: Chila AG, ed. Foundations of Osteopathic Medicine. 3rd 
ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2011:582-598.  
28. 
Kondrashova T, Lockwood MD. Innovative approach to teaching osteopathic manipulative medicine:  
the integration of ultrasonography. J Am Osteopath Assoc. 2015;115(4):212-220.