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 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.

Title: Analysis of electromyographic activity of selected muscles in exercises on selected balance surfaces. Objective: The objective of this dissertation was to document, compare and analyze electromyographic activity of m. gluteus maximus et medius, of m. erector spinae at the level L3 and of m. quadriceps vagus medialis et lateralis in exercises on selected unstable surfaces - on a cylindrical board and in balance sandals. Methods: The work was elaborated as a pilot study. Surface electromyography was used for objectification. The researched group consisted of 7 volunteers (5 women and 2 men), who had no serious injuries and surgeries in their anamnesis and none of them did any sports for a long period. Electromyographic activity of the above mentioned muscles was compared when doing two clearly defined exercises (stand on one lower extremity and hovering/gait on the spot) in balancing sandals and on a cylindrical board in sagittal plane. Results: The results only confirmed two hypotheses out of five ones. Namely it was the hypothesis no. 2 that the lowest activity of m. gluteus maximus was reached while doing exercise no. 3 - hovering/gait on the spot on a cylindrical board and the hypothesis no. 3 that the highest activity of m. erector spinae was reached while doing exercise no. 4 -...

<p>An objective measure of muscular low back pain (LBP) symptoms eludes clinicians. This study assessed efficacy of magnetic resonance imaging (MRI) of the lumbar multifidus using diffusion tensor imaging (DTI), blood oxygen level dependent (BOLD) signal fractal dimension (FD) analysis and muscle cross sectional area (CSA) in LBP assessment. MRI results were compared to two questionnaires, the Oswestry disability index (ODI) and visual analog score (VAS).</p> <p>Right-left asymmetry in both DTI metrics and T2-weighted (T2W) CSA were greater in the injured. Also, asymmetry measures were correlated with body mass index (BMI) but not age, height, or level of physical activity (measured via Godin activity questionnaire). The relationship between asymmetry and LBP symptoms in T2W and DTI scans increased for subjects with BMI below 35kg/m².</p> <p>BOLD FD did not scale with LBP symptoms. However, FD analysis showed promise following therapeutic Swedish massage, hypothesized as being related to local perfusion changes, indicating that FD is sensitive to changes in the lumbar muscle, just not LBP symptoms. Thus the BOLD FD does change with treatment, just not with the symptoms of LBP.</p> <p>When combining data from multiple scan types, the symptoms of LBP correlated best with the unweighted mean of DTI fractional anisotropy (FA) and T2W CSA asymmetry, and the correlation was greatest (R²=0.88) when only <em>symptomatic (not both symptomatic and control)</em> subjects with BMIs from 18-25kg/m² were considered. From these results there appears to be clinical utility in characterizing the symptoms of non-acute LBP using DTI and CSA.</p> / Doctor of Philosophy (PhD)