Comparison of US elastography and chemical shift magnetic resonance imaging in multifidus muscle fatty degeneration.

OBJECTIVE: The purpose of this study was to investigate the feasibility of the use of shear wave elastography (SWE) in comparison to chemical shift encoding (CSE) magnetic resonance imaging (MRI) for the evaluation of multifidus muscle fatty degeneration in patients with chronic low back pain. METHOD: Multifidus muscles were evaluated with the CSE-MRI and SWE examinations in control and patient groups. With the in-phase and out-phase sequences in CSE-MRI, signal intensity index (SII), and signal intensity suppression ratio (SISR) values; with the SWE method, shear wave velocity values were determined. Differences in the mean values of these parameters per level and study group were analyzed by Student's t-test. RESULTS: SWE revealed significantly lower stiffness at the L2-3 level, consistent with the signal index values (SII-SISR) showing increased fatty infiltration on MRI in the patient group. No such relationship was found at the L4-5 level or in control group. CONCLUSIONS: SWE may be a promising method to show muscle fatty infiltration at L2-3 level in patients with chronic low back pain.

OBJETIVO: Investigar la viabilidad del uso de la elastografía de ondas de corte en comparación con la resonancia magnética con codificación de desplazamiento químico (RM-CDQ) para la evaluación de la degeneración grasa del músculo multífido en pacientes con dolor lumbar crónico. MÉTODO: Los músculos multífidos se evaluaron con RM-CDQ y elastografía de ondas de corte en los grupos de control y de pacientes. Se consideraron las secuencias en fase y fuera de fase en RM-CDQ, y los valores del índice de intensidad de señal y del índice de supresión de intensidad de señal; con el método de elastografía de ondas de corte se determinaron los valores de velocidad de onda de corte. Las diferencias en los valores medios de estos parámetros por nivel y por grupo de estudio se analizaron mediante la prueba t de Student. RESULTADOS: La elastografía de ondas de corte reveló una rigidez significativamente menor en el nivel L2-3, consistente con los valores de los índices de señal que muestran una mayor infiltración grasa en la RM en el grupo de pacientes. No se encontró tal relación en el nivel L4-5 ni en el grupo de control. CONCLUSIONES: La elastografía de ondas de corte puede ser un método prometedor para mostrar la infiltración grasa muscular a nivel L2-3 en pacientes con dolor lumbar crónico.

Influence of Chronic Lameness on Thoracolumbar Musculus Multifidus Structure in the Horse.

The clinical relationship between equine limb lameness and secondary back dysfunction is largely unknown. Proper function of the spine is critical to maintain the integrity of the kinetic chain and attenuate forces from the appendicular skeleton. The musculus multifidus (m. multifidus) is the primary muscle providing spinal intersegmental stabilization and a functional relationship between m. multifidus hypertrophy and equine postural stability has been established. The relationship between equine thoracolumbar m. multifidus cross-sectional area (CSA) and limb lameness is unknown. The objective was to evaluate ultrasonographic changes in thoracolumbar m. multifidus CSA in horses with chronic single limb lameness, compared with sound horses. We hypothesized that the CSA of m. multifidus, ipsilateral to the lame limb would be smaller than the contralateral side, and within the sound group there would be no difference between sides. Thirty-six horses were enrolled, with twelve horses per group: sound, forelimb lame, and hindlimb lame. M. multifidus CSA was measured ultrasonographically at multiple spinal levels and compared between groups, spinal levels, and sides. M. multifidus CSA at the spinal level T18 was significantly larger than at all other measured levels, regardless of group (P ≤ .05). CSA at all levels was significantly larger in sound horses than the forelimb lame group, regardless of side (P = .002). This is the first study to evaluate the impact of chronic lameness on the axial skeleton and showed a decrease in m. multifidus CSA with forelimb lameness. These results support that axial skeletal adaptation occurs in response to naturally occurring chronic lameness.

Superficial and deep lumbar multifidus layers of asymptomatic individuals: intraday and interday reliability of the echo intensity measurement.

INTRODUCTION: Ultrasonography has been used to understand the functional and biomechanical aspects of the lumbar multifidus muscle in vivo. To characterize the multifidus echogenicity, the peculiarities of their superficial and deep layers must be considered. PURPOSE: The present paper aimed to characterize the lumbar multifidus echo intensity (EI), in both superficial and deep layers, in ultrasonography images acquired in longitudinal and transversal orientations. METHODS: Evaluator obtained two images in each side of the lumbar of the volunteer, who was lying on prone position. Ultrasonography images were taken with probe in transversal and longitudinal orientations. EI was estimated by means average value of the grayscale distribution histogram, by extracting from region of interest of the superficial and deep layer. All participants returned for a second test day. Two-way MANOVA test was applied to compare EI measurements, considering layers and side factors. The reliability and variability were analyzed by the intraclass correlation coefficient and standard error measurements (SEM), respectively. Two-way MANOVA found significant difference between the layers in the transversal and longitudinal images, but not between the sides. RESULTS: Interdays reliability ranged of reasonable to excellent, and SEM values were lower than 17.08%. The superficial layer of the multifidus muscle showed higher EI values than the deeper one. CONCLUSIONS: These analyses can serve as a basis for future studies approaching multifidus of the people with low back pain.

Relationship Between Postural Stability and Paraspinal Muscle Adaptation in Lame Horses Undergoing Rehabilitation.

Postural stability maintains balance, protects the spinal column, and allows accurate responses to destabilizing forces. The musculus multifidus (m. multifidus) is the major postural muscle located adjacent to the vertebrae along the length of the spinal column. Increased cross-sectional area (CSA) of the m. multifidus has been demonstrated in horses after a rehabilitation strengthening exercise program; however, correlation with functional postural stability has not been shown. The objective of the present study is to evaluate the relationship of the thoracolumbar m. multifidus CSA and measures of postural sway performance in lame horses undergoing rehabilitation exercises in clinical cases. Seven client-owned horses admitted to the equine rehabilitation service were included in the study. M. multifidus CSA was measured via ultrasonography at the start of a rehabilitation program (initial evaluation) and after 12 weeks of rehabilitation exercises (final evaluation). Postural sway data were also measured at initial and final evaluation. A significant increase in m. multifidus CSA was seen from initial to final evaluation. A moderate to strong correlation was present between m. multifidus CSA and postural sway variables. These results suggest that there is an association between postural stability and m. multifidus hypertrophy in lame horses undergoing individualized rehabilitation programs. However, more research is needed to provide a definitive answer on the nature of this relationship. Ideally, specific performance tests would better define and examine the relationship in which to guide clinicians in rehabilitation protocol development.

Parameters and functional analysis of the deep epaxial muscles in the thoracic, lumbar and sacral regions of the equine spine.

The epaxial muscles produce intervertebral rotation in the transverse, vertical and axial axes. These muscles also counteract the movements induced by gravitational and inertial forces and movements produced by antagonistic muscles and the intrinsic muscles of the pelvic limb. Their fascicles are innervated by the dorsal branch of the spinal nerve, which corresponds to the metamere of its cranial insertion in the spinous process. The structure allows the function of the muscles to be predicted: those with long and parallel fibres have a shortening function, whereas the muscles with short and oblique fibres have an antigravity action. In the horse, the multifidus muscle of the thoracolumbar region extends in multiple segments of two to eight vertebral motion segments (VMS). Functionally, the multifidus muscle is considered a spine stabiliser, maintaining VMS neutrality during spine rotations. However, there is evidence of the structural and functional heterogeneity of the equine thoracolumbar multifidus muscle, depending on the VMS considered, related to the complex control of the required neuromuscular activity. Osteoarticular lesions of the spine have been directly related to asymmetries of the multifidus muscle. The lateral (LDSM) and medial (MDSM) dorsal sacrocaudal muscles may be included in the multifidus complex, the function of which is also unclear in the lumbosacral region. The functional parameters of maximum force (Fmax ), maximum velocity of contraction (Vmax ) and joint moment (M) of the multifidus muscles inserted in the 4th, 9th, 12th and 17th thoracic and 3rd and 4th lumbar vertebrae of six horses were studied postmortem (for example: 4MT4 indicates the multifidus muscle that crosses four metameres with cranial insertion in the T4 vertebra). Furthermore, the structural and functional characteristics of LDSM and MDSM were determined. Data were analysed by analysis of variance (anova) in a randomised complete block design (P ≤ 0.05). For some muscles, the ordering of Vmax values was almost opposite to that of Fmax values, generally indicating antigravity or dynamic functions, depending on the muscle and VMS. The muscles 3MT12, 3ML3 and 4ML4 exhibited high Fmax and low Vmax values, indicating a stabilising action. The very long 7MT4 and 8MT4 multifidus had low Fmax and high Vmax values, suggesting a shortening action. However, some functional characteristics of interest did not fall within these general observations, also indicating a dual action. In summary, the results of the analysis of various structural and functional parameters confirm the structural and functional heterogeneity of the equine thoracolumbar multifidus complex, depending on the VMS, regardless of the number of metameres crossing each fascicle. To clarify the functions of the equine multifidus muscle complex, this study aimed to assess its functional parameters in thoracolumbar VMSs with different movement characteristics and in the MDSM and LDSM muscles, hypothesising that the functional parameters vary significantly when the VMS is considered.

Structural and functional characteristics of the thoracolumbar multifidus muscle in horses.

The multifidus muscle fascicles of horses attach to vertebral spinous processes after crossing between one to six metameres. The fascicles within one or two metameres are difficult to distinguish in horses. A vertebral motion segment is anatomically formed by two adjacent vertebrae and the interposed soft tissue structures, and excessive mobility of a vertebral motion segment frequently causes osteoarthropathies in sport horses. The importance of the equine multifidus muscle as a vertebral motion segment stabilizer has been demonstrated; however, there is scant documentation of the structure and function of this muscle. By studying six sport horses postmortem, the normalized muscle fibre lengths of the the multifidus muscle attached to the thoracic (T)4, T9, T12, T17 and lumbar (L)3 vertebral motion segments were determined and the relative areas occupied by fibre types I, IIA and IIX were measured in the same muscles after immunohistochemical typying. The values for the normalized muscle fibre lengths and the relative areas were analysed as completely randomized blocks using an anova (P ≤ 0.05). The vertebral motion segments of the T4 vertebra include multifidus bundles extending between two and eight metameres; the vertebral motion segments of the T9, T12, T17 and L3 vertebrae contain fascicles extending between two and four metameres The muscle fibres with high normalized lengths that insert into the T4 (three and eight metameres) vertebral motion segment tend to have smaller physiological cross-sectional areas, indicating their diminished capacity to generate isometric force. In contrast, the significantly decreased normalized muscle fibre lengths and the increased physiological cross-sectional areas of the fascicles of three metameres with insertions on T9, T17, T12, L3 and the fascicles of four metameres with insertions on L3 increase their capacities to generate isometric muscle force and neutralize excessive movements of the vertebral segments with great mobility. There were no significant differences in the values of relative areas occupied by fibre types I, IIA and IIX. In considering the relative areas occupied by the fibre types in the multifidus muscle fascicles attached to each vertebral motion segment examined, the relative area occupied by the type I fibres was found to be significantly higher in the T4 vertebral motion segment than in the other segments. It can be concluded that the equine multifidus muscle in horses is an immunohistochemically homogeneous muscle with various architectural designs that have functional significance according to the vertebral motion segments considered. The results obtained in this study can serve as a basis for future research aimed at understanding the posture and dynamics of the equine spine.

Reliability of new software in measuring cervical multifidus diameters and shoulder muscle strength in a synchronized way; an ultrasonographic study

OBJECTIVES: This study was conducted with the purpose of evaluating the inter-session reliability of new software to measure the diameters of the cervical multifidus muscle (CMM), both at rest and during isometric contractions of the shoulder abductors in subjects with neck pain and in healthy individuals.METHOD: In the present study, the reliability of measuring the diameters of the CMM with the Sonosynch software was evaluated by using 24 participants, including 12 subjects with chronic neck pain and 12 healthy individuals. The anterior-posterior diameter (APD) and the lateral diameter (LD) of the CMM were measured in a resting state and then repeated during isometric contraction of the shoulder abductors. Measurements were taken on separate occasions 3 to 7 days apart in order to determine inter-session reliability. Intraclass correlation coefficient (ICC), standard error of measurement (SEM), and smallest detectable difference (SDD) were used to evaluate the relative and absolute reliability, respectively.RESULTS: The Sonosynch software has shown to be highly reliable in measuring the diameters of the CMM both in healthy subjects and in those with neck pain. The ICCs 95% CI for APD ranged from 0.84 to 0.94 in subjects with neck pain and from 0.86 to 0.94 in healthy subjects. For LD, the ICC 95% CI ranged from 0.64 to 0.95 in subjects with neck pain and from 0.82 to 0.92 in healthy subjects.CONCLUSIONS: Ultrasonographic measurement of the diameters of the CMM using Sonosynch has proved to be reliable especially for APD in healthy subjects as well as subjects with neck pain.

Biometry by ultrasonography of the epaxial and pelvic musculature in equines trained with Pessoa's rein / Biometria por ultrassonografia da musculatura epaxial e pélvica em equinos treinados com rédea Pessoa

This study aimed to evaluate the use of Pessoa's rein in training equine, as a support in exercise training, on biometry by ultrasonography of the epaxial (Longíssimus Dorsi, Gluteus Medius e Musculus Multifidus) and pelvic musculature (Biceps Femoris e Semitendinosus). Thereby, eight Quarter Horse mares was used, with eight years on average age, 400kg of body weight, trained with the Pessoa's rein twice a week, for two months. Variables were measured before and after training, consisting of assessment thickness (cm) of the Longíssimus Dorsi and cross-sectional area (cm2) of muscles, Gluteus Medius, Biceps Femoris, Semitendinosus and Musculus Multifidus. It observed a significant effect of training with Pessoa's rein, on the Biceps Femoris (P<0.01) and Musculus Multifidus (P<0.01), which the average cross-sectional area at the final evaluation were of 28.66cm2 and 14.29cm2, respectively. Thus it can be conclude that training with Pessoa's rein modifies muscular function, promoting hypertrophy Musculus Multifidus and Biceps Femoris of horses.

Objetivou-se avaliar o emprego da rédea Pessoa no treinamento de equinos atletas, como auxiliar de condicionamento físico, sobre a biometria avaliada pela ultrassonografia das musculaturas epaxial (Longíssimus Dorsi, Gluteus Medius e Musculus Multifidus) e pélvica (Biceps Femoris e Semitendinosus). Foram utilizadas oito éguas da raça Quarto de Milha, com idade média de cinco anos, 400kg de peso vivo, treinadas com a rédea Pessoa duas vezes por semana, durante dois meses. As variáveis foram mensuradas, antes e após o treinamento, consistindo das avaliações de espessura (cm) do Longíssimus Dorsi e área transversal (cm2) dos músculos, Gluteus Medius, Biceps Femoris, Semitendinosus e Musculus Multifidus. Observou-se efeito significativo do treinamento com rédea Pessoa sobre os músculos Biceps Femoris (P<0,01) e Musculus Multifidus (P<0,01), no qual os valores médios da área transversal, na avaliação final, foram de 28,66cm2 e 14,29cm2, respectivamente. Concluiu-se que o treinamento com a rédea Pessoa modifica o funcionamento muscular, promovendo a hipertrofia do Musculus Multifidus e Biceps Femoris de equinos.

Biometria por ultrassonografia da musculatura epaxial e pélvica em equinos treinados com rédea Pessoa / Biometry by ultrasonography of the epaxial and pelvic musculature in equines trained with Pessoa's rein

Objetivou-se avaliar o emprego da rédea Pessoa no treinamento de equinos atletas, como auxiliar de condicionamento físico, sobre a biometria avaliada pela ultrassonografia das musculaturas epaxial (Longíssimus Dorsi, Gluteus Medius e Musculus Multifidus) e pélvica (Biceps Femoris e Semitendinosus). Foram utilizadas oito éguas da raça Quarto de Milha, com idade média de cinco anos, 400kg de peso vivo, treinadas com a rédea Pessoa duas vezes por semana, durante dois meses. As variáveis foram mensuradas, antes e após o treinamento, consistindo das avaliações de espessura (cm) do Longíssimus Dorsi e área transversal (cm2) dos músculos, Gluteus Medius, Biceps Femoris, Semitendinosus e Musculus Multifidus. Observou-se efeito significativo do treinamento com rédea Pessoa sobre os músculos Biceps Femoris (P 0,01) e Musculus Multifidus (P 0,01), no qual os valores médios da área transversal, na avaliação final, foram de 28,66cm2 e 14,29cm2, respectivamente. Concluiu-se que o treinamento com a rédea Pessoa modifica o funcionamento muscular, promovendo a hipertrofia do Musculus Multifidus e Biceps Femoris de equinos.(AU)

This study aimed to evaluate the use of Pessoa's rein in training equine, as a support in exercise training, on biometry by ultrasonography of the epaxial (Longíssimus Dorsi, Gluteus Medius e Musculus Multifidus) and pelvic musculature (Biceps Femoris e Semitendinosus). Thereby, eight Quarter Horse mares was used, with eight years on average age, 400kg of body weight, trained with the Pessoa's rein twice a week, for two months. Variables were measured before and after training, consisting of assessment thickness (cm) of the Longíssimus Dorsi and cross-sectional area (cm2) of muscles, Gluteus Medius, Biceps Femoris, Semitendinosus and Musculus Multifidus. It observed a significant effect of training with Pessoa's rein, on the Biceps Femoris (P 0.01) and Musculus Multifidus (P 0.01), which the average cross-sectional area at the final evaluation were of 28.66cm2 and 14.29cm2, respectively. Thus it can be conclude that training with Pessoa's rein modifies muscular function, promoting hypertrophy Musculus Multifidus and Biceps Femoris of horses.(AU)

Evaluation of the lumbar multifidus in rowers during spinal stabilization exercise / Avaliação dos multífidos lombares em atletas do remo durante exercício de estabilização vertebral / Evaluación del multifidus lumbar en los atletas de remo durante el ejercicio en la estabilización de la columna vertebral

Lumbar stabilization is important in high performance rowing due to the high incidence of low back pain. The purpose of this study was to evaluate the lumbar stabilizers muscles performance during an exercise of spinal segmental stabilization and in lumbar multifidus muscle thickness in rowing athletes trained and untrained for this exercise. Nine rowers trained with lumbar stabilization (TLS) and eight rowers without training (CON) participated in the study. Lumbar stabilization performance and multifidus muscle thickness were measured during a maximal voluntary isometric contraction. Lumbar stabilization performance was higher (p=0.015) in the TLS (mean 18.38 ± 8.00 mmHg) compared to the CON (9.31 ± 4.91 mmHg) group. Muscle thickness variation was higher (p=0.023) in the TLS (6.92% ± 3.98) compared to the CON (2.81% ± 1.40) group. Lumbar stabilization training is an efficient clinical tool to strengthen lumbar muscles and may help to prevent low back pain in rowers.

A estabilização lombar é fundamental em esportes de alto rendimento como o remo, devido a elevada incidência de lombalgia. O objetivo do presente estudo foi avaliar o desempenho dos músculos estabilizadores lombares e a espessura do músculo multífido lombar durante um exercício de estabilização segmentar vertebral em remadores. Nove remadores treinados com exercícios de estabilização lombar (TLS) e oito remadores destreinados (CON) foram avaliados. O desempenho dos músculos estabilizadores lombares e a espessura dos músculos multífidos foram mensurados durante uma contração voluntária isométrica máxima. O desempenho foi maior (p=0,015) no grupo TLS (18,38±8,00 mmHg) quando comparado ao grupo CON (9,31±4,91 mmHg). A variação da espessura muscular foi maior (p=0,023) no grupo TLS (6,92%±3.98) quando comparado com o grupo CON (2,81%±1,40). Treinamento de estabilização lombar é uma ferramenta clínica eficiente para fortalecimento da musculatura lombar e pode auxiliar na prevenção de lombalgia em remadores.

La estabilización lumbar es fundamental en la práctica de deportes como el remo de alto rendimiento, donde la lumbalgia aparece con frecuencia. El objetivo de este estudio fue evaluar el rendimiento de los músculos estabilizadores lumbares, así como el espesor del músculo multifido lumbar, durante un ejercicio de estabilización espinal segmentaria lumbar (una contracción isométrica voluntaria máxima) en atletas de remo. Fueron evaluados nueve remadores sometidos a entrenamiento con ejercicios de estabilización lumbar (TLS) y ocho sin este adiestramiento (CON). El rendimiento fue mayor (p=0,015) en el grupo TLS (18,38±8,00 mmHg) e comparación con el grupo CON (9,31±4,91 mmHg). Variación del espesor muscular fue mayor (p=0,023) en el grupo TLS (6,92%±3,98) en comparación con el grupo CON (2,81%±1,40). El entrenamiento lumbar es una herramienta clínica eficiente para el fortalecimiento de la musculatura lumbar e puede auxiliar en la prevención de lumbalgias en remadores.

Association of strength, muscle balance, and atrophy with pain and function in patients with degenerative spondylolisthesis.

PURPOSE: To analyze the relationship of strength, muscular balance, and atrophy with pain and function in patients with degenerative spondylolisthesis. STUDY DESIGN: Transversal, descriptive, and observational. PATIENTS AND METHODS: Institutional review board approval was obtained for this study. Twenty six patients ages 50 years and older, with degenerative spondylolisthesis at L4-L5. Measurements included Pain Visual Analogue Scale scores (VAS), Oswestry Disability Index scores (ODI), and isokinetic trunk testing; assessment of multifidus atrophy and spinal stenosis was performed by Magnetic Resonance Imaging (MRI). STATISTICS: Statistical analysis was performed using SPSS version 17.0 software for Windows. Pearson's correlation was used to ascertain the correlation between variables. ANOVA with analysis of covariance was used to determine the correlation between the remainder variables. Significance was set at p < 0.05. RESULTS: Of the 26 patients studied, with an average age of 60.23 ± 7.6 years, 20 had grade I spondylolisthesis and 6 were grade II. Correlation between the ODI scores and spondylolisthesis grading was significant (r=0.576, p=0.005); correlation between agonist/antagonist ratio in the isokinetic test (predominant extensor muscles over flexors) with the ODI scores was also significant (r=0.446, p=0.02), regardless of spinal stenosis. No correlation was found between functionality and pain with strength or multifidus atrophy. CONCLUSION: Muscle trunk imbalance with predominance of extensor over flexor muscles is associated with functional disability. Rehabilitation programs should be designed to improve muscle balance rather than muscle strength alone.

Study on placing electromyography electrodes on lumbar multifidus muscles

Several studies have been carried out in the last decades showing that specific exercises for the multifidus muscle can aid the lumbar back pain treatment. Hence, it is very important to determine the exact location of these muscles for an electromyographic evaluation. The objective of this study is to conduct a literature review to show the different techniques used to place invasive electrodes and test a specific technique through an anatomic study in cadavers. PubMed database in the period of 1970 to 2009 was used. The results suggest that the needle should be introduced 2.5 cm laterally and 1.0 cm cranially from the most inferior point of the spinous process at a 45° medial inclination toward the vertebral laminae until reaching the periosteum. For the L5 level, the needle is inserted at the same angle, 2.5 lateral to the midline between the posterior superior iliac spines.