This study was approved by the Rocky Vista University institutional review board. Twenty adult volunteer participants (10 men and 10 women; mean age, 28 years) were randomly recruited in the study. Participants, all of whom were students or employees of the university, provided written informed consent. Inclusion criteria required the study participants to be 20 years of age or older; to understand and sign informed consent; to be tolerant to osteopathic structural examination, ultrasonography scan, and OMT; to have no history of spinal surgery or trauma in the last 6 months; and to have no history of neuromuscular disorders, diabetic neuropathy, or autoimmune diseases.
Three osteopathic physicians (J.G., and 2 colleagues mentioned in Acknowledgements) from the Department of Osteopathic Principle and Practice, performed manual palpatory examinations of the lumbar region (L1-5) in 20 participants using standard protocol for assessing somatic dysfunction. Osteopathic assessments included evaluating skin changes (red reflex, skin drag, cold or hot temperature), muscle tone, paraspinal fullness, lumbar spine rotation, flexion, restricted motion, symmetry, and tenderness. The physician determined the location and parameters of osteopathic palpatory assessments for the diagnosis of somatic dysfunction before OMT, and then performed OMT. The same physician who conducted the initial osteopathic palpatory assessment to diagnose somatic dysfunction and performed the single OMT session, also performed the reassessment after OMT. OMT in this study was targeted to the iliocostalis lumborum, a muscle group commonly affected with low back pain conditions. OMT techniques used in the study included articulatory technique, balanced ligamentous tension (BLT), facilitated positional release (FPR), high-velocity, low-amplitude (HVLA), muscle energy, myofascial release, and the Still technique at the discretion of the osteopathic physician. A temporary skin marker was used to indicate the site of somatic dysfunction to ensure accurate subsequent SWV measurement in the same anatomic locations before OMT and after OMT.
SWE was then conducted on the paraspinal musculature of all the marked segments bilaterally using an Acuson S3000 ultrasonography system (Siemens Medical Solutions) equipped with 9L4 linear array transducer (4-9 MHz). Participants were lying in a prone position with back muscles relaxed (
Figure 1A). SWV (m/s) was measured in bilateral paraspinal musculature of the lumbar regions (L1-5;
Figure 1B) across the segments indicated by the initial osteopathic diagnosis and markings. A single operator performed SWE on the same 10 participants 2 times to test intraobserver repeatability. Two different ultrasonography operators (J.G. and a medical student) performed SWE on the other 10 participants separately to test interobserver reproducibility.
Standard ultrasonography machine settings for B-mode (
Figure 1C) and SWE (
Figure 1D) of lumbar paraspinal muscle included scanning frequency of 7 MHz, image depth of 4 cm, tissue harmonic imaging, dynamic range of 65, mechanical index of 1.6, and the size of region of interest of 2.65 cm × 1.0 cm (
Figure 2). Shear wave propagation slows when the tissue attenuation increases with increased depth. As reported, artifactual changes in the SWE field begin at depths of approximately 4 cm using a scanning frequency of 7 to 9 MHz.
17 Therefore, the image depth for paraspinal muscle SWE was standardized as 4 cm from the skin in this feasibility study. Each patient had 4 SWV measurements
. The average of the 4 SWV measurements in each region of tissue was used for analysis.
SWV data of both normal and somatic dysfunction segments was compared with the osteopathic physicians’ documented evaluation based on the osteopathic assessments before and after OMT. All data point variables were expressed as mean (SD). The mean SWV between the sites with and without somatic dysfunction was compared using an unpaired t test. The difference in muscle SWV before and after OMT was evaluated using a paired t test. Interobserver and intraobserver variation in performing SWE was tested using the intraclass correlation coefficient (ICC). The correlation between SWV and osteopathic assessment was analyzed by the Spearman rank correlation. A P<.05 was considered statistically significant. All statistical analyses were conducted by using SPSS software (version 25.4; IBM).