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Michele C Battie - One of the best experts on this subject based on the ideXlab platform.
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automatic Paraspinal Muscle segmentation in patients with lumbar pathology using deep convolutional neural network
Medical Image Computing and Computer-Assisted Intervention, 2019Co-Authors: Wenyao Xia, Maryse Fortin, Joshua Ahn, Hassan Rivaz, Michele C Battie, Terry M Peters, Yiming XiaoAbstract:Recent evidence suggests an association between low back pain (LBP) and changes in lumbar Paraspinal Muscle morphology and composition (i.e., fatty infiltration). Quantitative measurements of Muscle cross-sectional areas (CSAs) from MRI scans are commonly used to examine the relationship between Paraspinal Muscle characters and different lumbar conditions. The current investigation primarily uses manual segmentation that is time-consuming, laborious, and can be inconsistent. However, no automatic MRI segmentation algorithms exist for pathological data, likely due to the complex Paraspinal Muscle anatomy and high variability in Muscle composition among patients. We employed deep convolutional neural networks using U-Net+CRF-RNN with multi-data training to automatically segment Paraspinal Muscles from T2-weighted MRI axial slices at the L4-L5 and L5-S1 spinal levels and achieved averaged Dice score of 93.9\(\%\) and mean boundary distance of 1 mm. We also demonstrate the application using the segmentation results to reveal tissue characteristics of the Muscles in relation to age and sex.
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association between Paraspinal Muscle morphology clinical symptoms and functional status in patients with lumbar spinal stenosis
European Spine Journal, 2017Co-Authors: Maryse Fortin, Aron Lazary, Peter Paul Varga, Michele C BattieAbstract:Lumbar spinal stenosis (LSS) is a disabling condition associated with narrowing of the spinal canal or vertebral foramina. Paraspinal Muscle atrophy and fatty infiltration have been reported in patients with chronic LBP and disc herniation. However, very few imaging studies have examined Paraspinal Muscle morphology and composition in patients with LSS. The purpose of this study was to investigate the association of Paraspinal Muscle size, composition and asymmetry with functional status in patients with LSS. Thirty-six patients diagnosed with LSS at L4–L5 with neurogenic claudication were included. Paraspinal Muscle measurements were obtained from axial T2-weighted MR images, bilaterally, at the level of the superior and inferior vertebral endplates of L5. Muscle measurements of interest included: total cross-sectional area (CSA), functional CSA (FCSA), the ratio of FCSA to CSA (FCSA/CSA) as an indicator of Muscle composition, and relative % asymmetry in Muscle CSA. The association between Muscle parameters and other patient characteristics with function as indicated from Oswestry Disability Index (ODI) scores and pain interference status was investigated. Greater multifidus Muscle fatty infiltration (e.g., lower FCSA/CSA) and lower psoas relative CSA were associated with lower function (higher ODI and pain interference scores) in univariable and multivariable analyses. There was no association between the different Muscle parameters and stenosis severity or back or leg pain duration or severity. Our findings suggest an association of multifidus Muscle fatty infiltration and psoas Muscle size with functional status in patients diagnosed with LSS. Future prospective studies are needed to evaluate whether such Muscle parameters are associated with prognosis and functional recovery following surgical treatment.
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evaluation of an automated thresholding algorithm for the quantification of Paraspinal Muscle composition from mri images
Biomedical Engineering Online, 2017Co-Authors: Maryse Fortin, Michele C Battie, Mona Omidyeganeh, Omair Ahmad, Hassan RivazAbstract:The imaging assessment of Paraspinal Muscle morphology and fatty infiltration has gained considerable attention in the past decades, with reports suggesting an association between Muscle degenerative changes and low back pain (LBP). To date, qualitative and quantitative approaches have been used to assess Paraspinal Muscle composition. Though highly reliable, manual thresholding techniques are time consuming and not always feasible in a clinical setting. The tedious and rater-dependent nature of such manual thresholding techniques provides the impetus for the development of automated or semi-automated segmentation methods. The purpose of the present study was to develop and evaluate an automated thresholding algorithm for the assessment of Paraspinal Muscle composition. The reliability and validity of the Muscle measurements using the new automated thresholding algorithm were investigated through repeated measurements and comparison with measurements from an established, highly reliable manual thresholding technique. Magnetic resonance images of 30 patients with LBP were randomly selected cohort of patients participating in a project on commonly diagnosed lumbar pathologies in patients attending spine surgeon clinics. A series of T2-weighted MR images were used to train the algorithm; preprocessing techniques including adaptive histogram equalization method image adjustment scheme were used to enhance the quality and contrast of the images. All Muscle measurements were repeated twice using a manual thresholding technique and the novel automated thresholding algorithm, from axial T2-weigthed images, at least 5 days apart. The rater was blinded to all earlier measurements. Inter-method agreement and intra-rater reliability for each measurement method were assessed. The study did not received external funding and the authors have no disclosures. There was excellent agreement between the two methods with inter-method reliability coefficients (intraclass correlation coefficients) varying from 0.79 to 0.99. Bland and Altman plots further confirmed the agreement between the two methods. Intra-rater reliability and standard error of measurements were comparable between methods, with reliability coefficient varying between 0.95 and 0.99 for the manual thresholding and 0.97–0.99 for the automated algorithm. The proposed automated thresholding algorithm to assess Paraspinal Muscle size and composition measurements was highly reliable, with excellent agreement with the reference manual thresholding method.
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do variations in Paraspinal Muscle morphology and composition predict low back pain in men
Scandinavian Journal of Medicine & Science in Sports, 2015Co-Authors: Maryse Fortin, Laura E Gibbons, Tapio Videman, Michele C BattieAbstract:This longitudinal study aimed to clarify the longstanding controversy over whether variations in Paraspinal Muscle morphology (e.g., size, composition and asymmetry) are predictors of low back pain (LBP). A sample of 99 Finnish men were included in this population-based longitudinal study. Data were collected through a structured interview, physical examination and magnetic resonance imaging (MRI). Baseline measurements of the lumbar multifidus and erector spinae Muscles were obtained from T2-weighted axial images at L3-L4 and L5-S1, and interview data were obtained at baseline, 1- and 15-year follow-ups. Few of the Paraspinal Muscle parameters investigated were predictors of change in LBP frequency, intensity or sciatica at 1- and 15-year follow-ups in the population-based sample, and findings were not consistent across Muscles and spinal levels. However, greater multifidus and erector spinae fatty infiltration at L5-S1 was associated with a higher risk of having continued, frequent, persistent LBP at 1-year follow-up. None of the relationships observed was confounded by body mass index or the amount of physical activity at work or leisure. This longitudinal study provided evidence that variations in Paraspinal Muscle morphology on MRI have a limited, if not uncertain, role in the short- and long-term predictions of LBP in men.
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Paraspinal Muscle morphology and composition a 15 yr longitudinal magnetic resonance imaging study
Medicine and Science in Sports and Exercise, 2014Co-Authors: Maryse Fortin, Laura E Gibbons, Tapio Videman, Michele C BattieAbstract:AB Purpose: The purposes of this study were to define the natural progression of age-related changes of the lumbar Paraspinal Muscles during adulthood and to investigate the influence of lifestyle and individual factors (e.g., physical activity levels at work and leisure, body mass index, and low back pain [LBP]). Methods: This population-based longitudinal study included a sample of 99 adult male twins. Data were collected through a structured interview, physical examination, and magnetic resonance imaging. Measurements of the lumbar multifidus and erector spinae Muscles were obtained from T2-weighted axial images at L3-L4 and L5-S1 at baseline and 15-yr follow-up. Muscle cross-sectional area (CSA), functional CSA (FCSA) (fat-free mass), and FCSA/CSA (composition) as well as CSA and FCSA asymmetry and FCSA/CSA side-to-side differences were measured. Results: Subjects' mean +/- SD age was 47.3 +/- 7.4 yr at baseline and 62.3 +/- 8.0 yr at follow-up. During the 15-yr period, both Muscles exhibited a decrease in CSA and FCSA and an increase in fatty infiltration and side-to-side differences in size and composition at both spinal levels. Both Muscles displayed greater changes at L5-S1 than L3-L4. Age and BMI were found to be significantly associated with the degree of Paraspinal Muscle changes over time. However, there was no association between the change in Paraspinal Muscle size, composition, or asymmetry with the level of physical demands at work or leisure or LBP history. Conclusions: The present longitudinal study suggests that over adulthood, the multifidus and erector spinae undergo similar morphological changes. Moreover, our findings suggest that the long-term progression of lumbar Paraspinal Muscle changes evaluated through magnetic resonance imaging are not associated with the range of physical demand levels as were typical of Finnish men or LBP history
Maryse Fortin - One of the best experts on this subject based on the ideXlab platform.
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automatic Paraspinal Muscle segmentation in patients with lumbar pathology using deep convolutional neural network
Medical Image Computing and Computer-Assisted Intervention, 2019Co-Authors: Wenyao Xia, Maryse Fortin, Joshua Ahn, Hassan Rivaz, Michele C Battie, Terry M Peters, Yiming XiaoAbstract:Recent evidence suggests an association between low back pain (LBP) and changes in lumbar Paraspinal Muscle morphology and composition (i.e., fatty infiltration). Quantitative measurements of Muscle cross-sectional areas (CSAs) from MRI scans are commonly used to examine the relationship between Paraspinal Muscle characters and different lumbar conditions. The current investigation primarily uses manual segmentation that is time-consuming, laborious, and can be inconsistent. However, no automatic MRI segmentation algorithms exist for pathological data, likely due to the complex Paraspinal Muscle anatomy and high variability in Muscle composition among patients. We employed deep convolutional neural networks using U-Net+CRF-RNN with multi-data training to automatically segment Paraspinal Muscles from T2-weighted MRI axial slices at the L4-L5 and L5-S1 spinal levels and achieved averaged Dice score of 93.9\(\%\) and mean boundary distance of 1 mm. We also demonstrate the application using the segmentation results to reveal tissue characteristics of the Muscles in relation to age and sex.
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association between Paraspinal Muscle morphology clinical symptoms and functional status in patients with lumbar spinal stenosis
European Spine Journal, 2017Co-Authors: Maryse Fortin, Aron Lazary, Peter Paul Varga, Michele C BattieAbstract:Lumbar spinal stenosis (LSS) is a disabling condition associated with narrowing of the spinal canal or vertebral foramina. Paraspinal Muscle atrophy and fatty infiltration have been reported in patients with chronic LBP and disc herniation. However, very few imaging studies have examined Paraspinal Muscle morphology and composition in patients with LSS. The purpose of this study was to investigate the association of Paraspinal Muscle size, composition and asymmetry with functional status in patients with LSS. Thirty-six patients diagnosed with LSS at L4–L5 with neurogenic claudication were included. Paraspinal Muscle measurements were obtained from axial T2-weighted MR images, bilaterally, at the level of the superior and inferior vertebral endplates of L5. Muscle measurements of interest included: total cross-sectional area (CSA), functional CSA (FCSA), the ratio of FCSA to CSA (FCSA/CSA) as an indicator of Muscle composition, and relative % asymmetry in Muscle CSA. The association between Muscle parameters and other patient characteristics with function as indicated from Oswestry Disability Index (ODI) scores and pain interference status was investigated. Greater multifidus Muscle fatty infiltration (e.g., lower FCSA/CSA) and lower psoas relative CSA were associated with lower function (higher ODI and pain interference scores) in univariable and multivariable analyses. There was no association between the different Muscle parameters and stenosis severity or back or leg pain duration or severity. Our findings suggest an association of multifidus Muscle fatty infiltration and psoas Muscle size with functional status in patients diagnosed with LSS. Future prospective studies are needed to evaluate whether such Muscle parameters are associated with prognosis and functional recovery following surgical treatment.
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Evaluation of an automated thresholding algorithm for the quantification of Paraspinal Muscle composition from MRI images
BioMedical Engineering OnLine, 2017Co-Authors: Maryse Fortin, Mona Omidyeganeh, Michele Crites Battié, Omair Ahmad, Hassan RivazAbstract:Background The imaging assessment of Paraspinal Muscle morphology and fatty infiltration has gained considerable attention in the past decades, with reports suggesting an association between Muscle degenerative changes and low back pain (LBP). To date, qualitative and quantitative approaches have been used to assess Paraspinal Muscle composition. Though highly reliable, manual thresholding techniques are time consuming and not always feasible in a clinical setting. The tedious and rater-dependent nature of such manual thresholding techniques provides the impetus for the development of automated or semi-automated segmentation methods. The purpose of the present study was to develop and evaluate an automated thresholding algorithm for the assessment of Paraspinal Muscle composition. The reliability and validity of the Muscle measurements using the new automated thresholding algorithm were investigated through repeated measurements and comparison with measurements from an established, highly reliable manual thresholding technique. Methods Magnetic resonance images of 30 patients with LBP were randomly selected cohort of patients participating in a project on commonly diagnosed lumbar pathologies in patients attending spine surgeon clinics. A series of T2-weighted MR images were used to train the algorithm; preprocessing techniques including adaptive histogram equalization method image adjustment scheme were used to enhance the quality and contrast of the images. All Muscle measurements were repeated twice using a manual thresholding technique and the novel automated thresholding algorithm, from axial T2-weigthed images, at least 5 days apart. The rater was blinded to all earlier measurements. Inter-method agreement and intra-rater reliability for each measurement method were assessed. The study did not received external funding and the authors have no disclosures. Results There was excellent agreement between the two methods with inter-method reliability coefficients (intraclass correlation coefficients) varying from 0.79 to 0.99. Bland and Altman plots further confirmed the agreement between the two methods. Intra-rater reliability and standard error of measurements were comparable between methods, with reliability coefficient varying between 0.95 and 0.99 for the manual thresholding and 0.97–0.99 for the automated algorithm. Conclusion The proposed automated thresholding algorithm to assess Paraspinal Muscle size and composition measurements was highly reliable, with excellent agreement with the reference manual thresholding method.
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evaluation of an automated thresholding algorithm for the quantification of Paraspinal Muscle composition from mri images
Biomedical Engineering Online, 2017Co-Authors: Maryse Fortin, Michele C Battie, Mona Omidyeganeh, Omair Ahmad, Hassan RivazAbstract:The imaging assessment of Paraspinal Muscle morphology and fatty infiltration has gained considerable attention in the past decades, with reports suggesting an association between Muscle degenerative changes and low back pain (LBP). To date, qualitative and quantitative approaches have been used to assess Paraspinal Muscle composition. Though highly reliable, manual thresholding techniques are time consuming and not always feasible in a clinical setting. The tedious and rater-dependent nature of such manual thresholding techniques provides the impetus for the development of automated or semi-automated segmentation methods. The purpose of the present study was to develop and evaluate an automated thresholding algorithm for the assessment of Paraspinal Muscle composition. The reliability and validity of the Muscle measurements using the new automated thresholding algorithm were investigated through repeated measurements and comparison with measurements from an established, highly reliable manual thresholding technique. Magnetic resonance images of 30 patients with LBP were randomly selected cohort of patients participating in a project on commonly diagnosed lumbar pathologies in patients attending spine surgeon clinics. A series of T2-weighted MR images were used to train the algorithm; preprocessing techniques including adaptive histogram equalization method image adjustment scheme were used to enhance the quality and contrast of the images. All Muscle measurements were repeated twice using a manual thresholding technique and the novel automated thresholding algorithm, from axial T2-weigthed images, at least 5 days apart. The rater was blinded to all earlier measurements. Inter-method agreement and intra-rater reliability for each measurement method were assessed. The study did not received external funding and the authors have no disclosures. There was excellent agreement between the two methods with inter-method reliability coefficients (intraclass correlation coefficients) varying from 0.79 to 0.99. Bland and Altman plots further confirmed the agreement between the two methods. Intra-rater reliability and standard error of measurements were comparable between methods, with reliability coefficient varying between 0.95 and 0.99 for the manual thresholding and 0.97–0.99 for the automated algorithm. The proposed automated thresholding algorithm to assess Paraspinal Muscle size and composition measurements was highly reliable, with excellent agreement with the reference manual thresholding method.
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do variations in Paraspinal Muscle morphology and composition predict low back pain in men
Scandinavian Journal of Medicine & Science in Sports, 2015Co-Authors: Maryse Fortin, Laura E Gibbons, Tapio Videman, Michele C BattieAbstract:This longitudinal study aimed to clarify the longstanding controversy over whether variations in Paraspinal Muscle morphology (e.g., size, composition and asymmetry) are predictors of low back pain (LBP). A sample of 99 Finnish men were included in this population-based longitudinal study. Data were collected through a structured interview, physical examination and magnetic resonance imaging (MRI). Baseline measurements of the lumbar multifidus and erector spinae Muscles were obtained from T2-weighted axial images at L3-L4 and L5-S1, and interview data were obtained at baseline, 1- and 15-year follow-ups. Few of the Paraspinal Muscle parameters investigated were predictors of change in LBP frequency, intensity or sciatica at 1- and 15-year follow-ups in the population-based sample, and findings were not consistent across Muscles and spinal levels. However, greater multifidus and erector spinae fatty infiltration at L5-S1 was associated with a higher risk of having continued, frequent, persistent LBP at 1-year follow-up. None of the relationships observed was confounded by body mass index or the amount of physical activity at work or leisure. This longitudinal study provided evidence that variations in Paraspinal Muscle morphology on MRI have a limited, if not uncertain, role in the short- and long-term predictions of LBP in men.
Olavi Airaksinen - One of the best experts on this subject based on the ideXlab platform.
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lumbar Paraspinal Muscle function perception of lumbar position and postural control in disc herniation related back pain
Spine, 2003Co-Authors: Ville Leinonen, Markku Kankaanpää, Osmo Hänninen, Olavi Airaksinen, Matti Luukkonen, Martti Kansanen, Simo TaimelaAbstract:STUDY DESIGN A follow-up study evaluating postural control, lumbar movement perception, and Paraspinal Muscle reflexes in disc herniation-related chronic low back pain (LBP) before and after discectomy. OBJECTIVES To assess the effect of discectomy on postural control, lumbar perception, and reflex activation of Paraspinal Muscles during sudden upper limb loading. SUMMARY OF BACKGROUND DATA Impaired Muscle function, postural control, and lumbar proprioception have been observed in LBP. However, they have not been studied in sciatica patients after surgery. METHODS The study included 20 patients selected for an operation for chronic LBP caused by disc herniation and 15 controls without chronic LBP. The Paraspinal Muscle responses for upper limb loading during unexpected and expected conditions were measured by surface electromyography. The ability to sense lumbar rotation was assessed in a previously validated motorized trunk rotation unit in the seated position. The postural control was measured with a vertical force platform. Pain, disability, and depression scores were recorded. RESULTS Patients had poorer lumbar perception (P = 0.012) and postural control (P < 0.05) than did healthy controls. The postural control remained unchanged, but lumbar perception (P = 0.054) and the lumbar feed-forward control (P = 0.043) improved after the surgery. CONCLUSIONS The results demonstrate impaired lumbar proprioception and postural control in sciatica patients. During short-term follow-up after operative treatment, postural control does not seem to change, but impaired lumbar proprioception and feed-forward control of Paraspinal Muscles seem to recover.
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Paraspinal Muscle denervation, paradoxically good lumbar endurance, and an abnormal flexion-extension cycle in lumbar spinal stenosis.
Spine, 2003Co-Authors: Ville Leinonen, Markku Kankaanpää, Osmo Hänninen, Simo Taimela, Sara Määttä, Arto Herno, Juhani Partanen, Olavi AiraksinenAbstract:STUDY DESIGN A descriptive study was conducted to investigate the Paraspinal Muscle function in patients with lumbar spinal stenosis. OBJECTIVE To evaluate Paraspinal Muscle innervation and endurance in lumbar spinal stenosis. SUMMARY OF BACKGROUND DATA Abnormal lumbar Paraspinal Muscle function is associated with chronic low back pain. Abnormal neurophysiologic findings of the lower limbs often are observed in lumbar spinal stenosis, and abnormal lumbar function also can be expected. However, Paraspinal Muscle function and innervation have not been studied in lumbar spinal stenosis. METHODS The study evaluated 25 patients with clinically and radiologically diagnosed lumbar spinal stenosis. Electromyography of the Paraspinal Muscles was performed from L3 to S1 bilaterally using a concentric needle. At least 20 insertions were analyzed from each Muscle. The aim of the examination was to detect abnormal spontaneous activity associated with axonal damage (fibrillation potentials, positive sharp waves, and complex repetitive discharges). Paraspinal Muscle activity during trunk flexion-extension movement and Muscle endurance during the dynamic isoinertial back endurance test were assessed by surface electromyography. Muscle fatigue was calculated using mean power frequency analysis. RESULTS Abnormal findings in needle electromyography of the Paraspinal Muscles were observed in 18 of the 22 (81.8%) examined patients. Abnormal flexion-extension activation of the Paraspinal Muscles was observed in all the examined patients. The change in mean power frequency was significantly smaller than in previously evaluated healthy subjects and patients with nonspecific chronic low back pain (P < 0.001) who were not experiencing symptoms of lumbar spinal stenosis. Paraspinal Muscle fatigability was not associated with the denervation of the Muscles. CONCLUSIONS Denervation and abnormal activation of lumbar Paraspinal Muscles are frequent findings in patients with lumbar spinal stenosis who have not undergone surgery. The Paraspinal Muscle endurance of the patients was unexpectedly good.
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Paraspinal Muscle responses during sudden upper limb loading.
European journal of applied physiology, 2002Co-Authors: Ville Leinonen, Markku Kankaanpää, Osmo Hänninen, Olavi Airaksinen, Simo TaimelaAbstract:The Paraspinal Muscle responses for unexpected and expected upper limb loading were investigated by surface EMG of 20 healthy volunteers. The simultaneous trunk and hand accelerations with Paraspinal, biceps brachii and soleus Muscles EMG were measured in four subjects. A short-latency response of approximately 50 ms was observed in Paraspinal Muscles. The latency was approximately 3 ms shorter (P = 0.017) during "expected" trials on average and the latency shortened during the first three expected trials (P = 0.02). Anticipation also decreased the magnitude of the response (P < 0.05). Trunk movement initiated approximately 35 ms and approximately 50 ms after the impact of the load at T6 and T12 levels, respectively. In conclusion, visual expectation shortens the latency and decreases the magnitude of the Paraspinal Muscle response to sudden upper limb loading. Also, the trial repetition has an effect on reflex latency if visual information is available. These results indicate that anticipation modulates the reflex control of Paraspinal Muscles, which may be significant in understanding spinal function.
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lumbar Paraspinal Muscle fatigability in repetitive isoinertial loading emg spectral indices borg scale and endurance time
European Journal of Applied Physiology, 1997Co-Authors: Markku Kankaanpää, Olavi Airaksinen, Simo Taimela, Charles L Webber, Osmo HänninenAbstract:The purpose of this study was to develop a submaximal repetitive isoinertial back Muscle endurance test by defining the relationships between the power spectral indices of Paraspinal Muscle electromyographic (EMG) activities, endurance time and a subjective estimate of fatigue (Borg scale). Bilateral surface EMG recordings were obtained over the lumbar Paraspinal Muscles in ten individuals who were currently free from back pain. All subjects performed repetitive upper trunk extensions (25° flexion and 5° extension, 30 repetitions per min), while movement below the third lumbar vertebral body was mechanically restricted. The load level depended upon upper body mass, sex, and age. The tests continued for as long as the subjects were able to maintain the required repetition rate (endurance time). Median (MF) and mean power frequency (MPF) slopes were calculated by performing a fast Fourier transformation after confirmation of EMG stationarity by recurrence quantification analysis. MF and MPF correlations with endurance time/Borg scale were measured for the first 60 s (0.60–0.88/0.42–0.86), the first 90 s (0.62–0.89/0.52–0.90), the first 120 s (0.50–0.76/0.41–0.73), and the entire repetitive run (0.63–0.88/0.54–0.90). To test for the reproducibility of the spectral indices, EMGs were recorded for 2 min during repetitive loading from the same subjects on two consecutive days. Corresponding spectral slopes of MF and MPF were correlated at 60 s (0.36–0.93), 90 s (0.58–0.92), and 120 s (0.70–0.94) at the L3–L4 and L5–S1 levels, indicating good reproducibility of results from alternate recording sessions at the L5–S1 level. It is concluded that Paraspinal Muscle spectral indices (MF and MPF) measured before the onset of total Muscle fatigue are good predictors of endurance time and are closely related to the subjective perception of fatigue.
Ansgar Schwirtz - One of the best experts on this subject based on the ideXlab platform.
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Association of Paraspinal Muscle water-fat MRI-based measurements with isometric strength measurements.
European radiology, 2018Co-Authors: Sarah Schlaeger, Stephanie Inhuber, Alexander Rohrmeier, Michael Dieckmeyer, Friedemann Freitag, Elisabeth Klupp, Dominik Weidlich, Georg Feuerriegel, F. Kreuzpointner, Ansgar SchwirtzAbstract:Chemical shift encoding-based water–fat MRI derived proton density fat fraction (PDFF) of the Paraspinal Muscles has been emerging as a surrogate marker in subjects with sarcopenia, lower back pain, injuries and neuromuscular disorders. The present study investigates the performance of Paraspinal Muscle PDFF and cross-sectional area (CSA) in predicting isometric Muscle strength. Twenty-six healthy subjects (57.7% women; age: 30 ± 6 years) underwent 3T axial MRI of the lumbar spine using a six-echo 3D spoiled gradient echo sequence for chemical shift encoding-based water–fat separation. Erector spinae and psoas Muscles were segmented bilaterally from L2 level to L5 level to determine CSA and PDFF. Muscle flexion and extension maximum isometric torque values [Nm] at the back were measured with an isokinetic dynamometer. Significant correlations between CSA and Muscle strength measurements were observed for erector spinae Muscle CSA (r = 0.40; p = 0.044) and psoas Muscle CSA (r = 0.61; p = 0.001) with relative flexion strength. Erector spinae Muscle PDFF correlated significantly with relative Muscle strength (extension: r = -0.51; p = 0.008; flexion: r = -0.54; p = 0.005). Erector spinae Muscle PDFF, but not CSA, remained a statistically significant (p < 0.05) predictor of relative extensor strength in multivariate regression models (R2adj = 0.34; p = 0.002). PDFF measurements improved the prediction of Paraspinal Muscle strength beyond CSA. Therefore, chemical shift encoding-based water–fat MRI may be used to detect subtle changes in the Paraspinal Muscle composition. • We investigated the association of Paraspinal Muscle fat fraction based on chemical shift encoding-based water–fat MRI with isometric strength measurements in healthy subjects. • Erector spinae Muscle PDFF correlated significantly with relative Muscle strength. • PDFF measurements improved prediction of Paraspinal Muscle strength beyond CSA.
Joel G. Pickar - One of the best experts on this subject based on the ideXlab platform.
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Dynamic responsiveness of lumbar Paraspinal Muscle spindles during vertebral movement in the cat
Experimental Brain Research, 2009Co-Authors: Dong-yuan Cao, Partap S. Khalsa, Joel G. PickarAbstract:Muscle spindles provide essential information for appropriate motor control. In appendicular Muscles, much is known about their position and movement sensitivities, but little is known about the axial Muscles of the low back. We investigated the dynamic responsiveness of lumbar Paraspinal Muscle spindle afferents from L_6 dorsal root filaments during constant velocity movement of the L_6 vertebra (the feline has seven lumbar vertebrae) in Nembutal-anesthetized cats. Actuations of 1 mm applied at the L_6 spinous process were delivered at 0.5, 1.0 and 2.0 mm/s. The slow velocity component was measured as the slope of the relationship between displacement during the constant velocity ramp and instantaneous discharge frequency. The quick velocity component was the slope’s intercept at zero displacement. The peak component was determined as the highest discharge rates occurring near the end of the ramp compared with control. The slow velocity component over the three increasing velocities was 23.9 (9.9), 21.6 (9.6) and 20.5 (9.5) imp/(s mm) [mean (SD)], respectively. The quick velocity component was 28.4 (8.6), 31.4 (9.8) and 35.8 (10.6) imp/s, respectively. These measures of dynamic responsiveness were at least 5–10 times higher compared with values reported for appendicular Muscle spindles. The peak component’s velocity sensitivity was 2.9 (imp/s)/(mm/s) [0.2, 5.5, lower, upper 95% confidence interval] similar to that for cervical Paraspinal Muscles as well as appendicular Muscles. Increased dynamic responsiveness of lumbar Paraspinal Muscle spindles may insure central driving to insure control of intervertebral motion during changes in spinal orientation. It may also contribute to large, rapid and potentially injurious increases in Paraspinal Muscle activity during sudden and unexpected Muscle stretch.
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Thoracolumbar fascia does not influence proprioceptive signaling from lumbar Paraspinal Muscle spindles in the cat
Journal of anatomy, 2009Co-Authors: Dong-yuan Cao, Joel G. PickarAbstract:The thoracolumbar fascia attaches to the lumbar spinous processes and encloses the Paraspinal Muscles to form a Muscle compartment. Because Muscle spindles can respond to transverse forces applied at a Muscle’s surface, we were interested in the mechanical effects this fascia may have on proprioceptive signaling from lumbar Paraspinal Muscles during vertebral movement. The discharge of Paraspinal Muscle spindles at rest and in response to Muscle history were investigated in the presence and absence of the thoracolumbar fascia in anesthetized cats. Muscle-history was induced by positioning the L6 vertebra in conditioning directions that lengthened and shortened the Paraspinal Muscles. The vertebra was then returned to an intermediate position for testing the spindles. Neither resting discharge (P = 0.49) nor the effects of Muscle history (P > 0.30) was significantly different with the fascia intact vs. removed. Our data showed that the thoracolumbar fascia did not influence proprioceptive signaling from lumbar Paraspinal Muscles spindles during small passive vertebral movements in cats. In addition, comparison of the transverse threshold pressures needed to stimulate our sample of Muscle spindles in the cat with the thoracolumbar fascia compartmental pressures measured in humans during previous studies suggests that the thoracolumbar fascia likely does not affect proprioceptive signaling from lumbar Paraspinal Muscle spindles in humans.
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Paraspinal Muscle spindle responses to the duration of a spinal manipulation under force control
Journal of Manipulative and Physiological Therapeutics, 2006Co-Authors: Joel G. Pickar, Yuming KangAbstract:OBJECTIVE: More than 90% of chiropractic patients receive high-velocity, low-amplitude spinal manipulation (HVLA-SM) as part of their chiropractic care. The purpose of the current study was determine how the duration of a lumbar HVLA-SM given under force control affects the discharge of Paraspinal Muscle spindle afferents. METHODS: Experiments were performed on deeply anesthetized adult cats treated in accordance with the Guiding Principles in the Care and Use of Animals approved by the American Physiological Society. Muscle spindle afferents were identified in the dorsal roots. Neural activity was recorded from individual spindles located in the low back predominately from multifidus and longissimus Muscles. Spinal manipulative loads were applied to the L6 vertebra. Force-time profiles were half-sine waves with impulse durations of 25, 50, 100, 200, 400, and 800 milliseconds, delivered at constant magnitudes of 33%, 66%, or 100% body weight. The relationships between spinal manipulation duration and Muscle spindle responses were determined using a randomized block design. RESULTS: Mean instantaneous discharge frequency increased with decreasing impulse duration. There appeared to be a threshold effect for impulse duration below which the increase in Muscle spindle discharge changed greatly with decreasing impulse duration and above which the discharge did not substantially change with decreasing impulse duration. This threshold was in the vicinity of the duration of an HVLA-SM applied clinically (
