Reliability of diagnostic ultrasound in measuring the multifidus muscle

Intra-rater reliability of rehabilitative ultrasound imaging of erector spinae and gluteus medius muscles in patients with low back pain

BACKGROUND

Low back pain (LBP) is one of the most common conditions in the United States. Dysfunctional patterns of the erector spinae (ES) and gluteus medius (GM) muscles often accompany episodes of LBP.

OBJECTIVES

To evaluate the intra-rater reliability of rehabilitative ultrasound imaging (RUSI) in obtaining thickness measurements of the ES and GM muscles at rest and during submaximal contraction.

DESIGN

Single-group repeated-measures reliability study.

METHODS

A volunteer sample of 30 adults with current LBP was examined. Thickness measurements of the ES and GM at rest and during contraction were obtained by using RUSI during a single session. Intraclass correlation coefficients (ICC) were used to estimate reliability. Reliability was further assessed by calculating standard error of measurement (SEM) and minimal detectable change (MDC).

RESULTS

By using a mean of 3 measures, intra-rater reliability estimates ranged from 0.999 to 0.999 for ES, and 0.998 to 0.999 for GM. Reliability estimates for single thickness measures ranged from 0.997 to 0.998 for ES, and 0.995 to 0.997 for GM. Reliability estimates were lower for percent thickness change measures than the corresponding single thickness measures for all conditions.

CONCLUSIONS

RUSI thickness measurements of the ES and GM muscles in patients with LBP, when based on the mean of 3 measures, are highly reliable when taken by a single examiner in a single session.

Analysis of lumbar spine loading during walking in patients with chronic low back pain and healthy controls: An OpenSim-Based study

Low back pain (LBP) is one of the most prevalent and disabling disease worldwide. However, the specific biomechanical changes due to LBP are still controversial. The purpose of this study was to estimate the lumbar and lower limb kinematics, lumbar moments and loads, muscle forces and activation during walking in healthy adults and LBP. A total of 18 healthy controls and 19 patients with chronic LBP were tested for walking at a comfortable speed. The kinematic and dynamic data of the subjects were collected by 3D motion capture system and force plates respectively, and then the motion simulation was performed by OpenSim. The OpenSim musculoskeletal model was used to calculate lumbar, hip, knee and ankle joint angle variations, lumbar moments and loads, muscle forces and activation of eight major lumbar muscles. In our results, significant lower lumbar axial rotation angle, lumbar flexion/extension and axial rotation moments, as well as the muscle forces of the four muscles and muscle activation of two muscles were found in patients with LBP than those of the healthy controls (p < 0.05). This study may help providing theoretical support for the evaluation and rehabilitation treatment intervention of patients with LBP.

Effect of aquatic exercise versus standard care on paraspinal and gluteal muscles morphology in individuals with chronic low back pain: a randomized controlled trial protocol

BACKGROUND

Low back pain (LBP) is one of the most disabling diseases and a major health issue. Despite the evidence of a link between paraspinal and gluteal muscle dysfunction and LBP, it is unknown whether aquatic exercises can lead to improvements in paraspinal and gluteal muscle morphology and function, and whether improvements in overall muscle health are associated with improvements in patients' outcomes. The unique properties of water allow a water-based exercise program to be tailored to the needs of those suffering from LBP. This study uses magnetic resonance imaging (MRI) to investigate the effect of an aquatic exercise program versus standard exercise on 1) paraspinal and gluteal muscle size, quality and strength and 2) pain, disability, and psychological factors (pain related fear, depression, anxiety, sleep quality) in chronic LBP.

METHODS

This study will include 34 participants with chronic non-specific LBP and moderate to severe disability, aged between 18 and 65, who will be randomly assigned (1:1) to the aquatic exercise group or land-based standard care exercise group. Both groups will receive 20 supervised sessions, twice per week over 10 weeks. MRIs will be obtained along the lumbosacral spine (L1-L5) and pelvis at the start and end of the intervention to assess the effect of each exercise intervention on paraspinal and gluteal muscle size and quality. Pre- to post-intervention changes in all outcomes between each group will be assessed, and the association between the changes in back muscle quality and clinical outcomes will be examined. Between-subjects repeated measure analysis of variance will be used to examine the changes in paraspinal muscle morphology over the different time points. Linear mixed models will be used to assess whether baseline scores can modify the response to the exercise therapy treatment.

DISCUSSION

This study will determine if water-based exercises targeting the lower back and gluteal muscles can lead to important changes in muscle quality and function, and their possible relation with patients' pain and functional improvements. Our findings will have strong clinical implications and provide preliminary data to design a community program to better support individuals with chronic LBP.

TRIAL REGISTRATION

NCT05823857, registered prospectively on April 27th, 2023.

The Effects of Combined Motor Control and Isolated Extensor Strengthening versus General Exercise on Paraspinal Muscle Morphology, Composition, and Function in Patients with Chronic Low Back Pain: A Randomized Controlled Trial

Low back pain (LBP), a globally widespread and persistent musculoskeletal disorder, benefits from exercise therapy. However, it remains unclear which type leads to greater changes in paraspinal muscle health. This study aimed to (1) compare the effects of a combined motor control and isolated lumbar extension exercise (MC+ILEX) versus a general exercise (GE) intervention on paraspinal muscle morphology, composition, and function, and (2) examine whether alterations in paraspinal muscle health were correlated with improvements in pain, function, and quality of life. Fifty participants with chronic LBP were randomly assigned to each group and underwent a 12-week supervised intervention program. Magnetic resonance imaging and ultrasound assessments were acquired at baseline, 6 and 12 weeks to examine the impact of each intervention on erector spinae (ES) and multifidus (MF) muscle size (cross-sectional area, CSA), composition, and function at L4-L5 and L5-S1. Self-reported questionnaires were also acquired to assess participant-oriented outcomes. Our findings indicated that the MC+ILEX group demonstrated greater improvements in MF and ES CSA, along with MF thickness at both levels (all p < 0.01). Both groups significantly improved in pain, function, and quality of life. This study provided preliminary results suggesting that an MC+ILEX intervention may improve paraspinal morphology while decreasing pain and disability.

Studies on Reliability and Measurement Error of Measurements in Medicine - From Design to Statistics Explained for Medical Researchers

Reliability and measurement error are measurement properties that quantify the influence of specific sources of variation, such as raters, type of machine, or time, on the score of the individual measurement. Several designs can be chosen to assess reliability and measurement error of a measurement. Differences in design are due to specific choices about which sources of variation are varied over the repeated measurements in stable patients, which potential sources of variation are kept stable (ie, restricted), and about whether or not the entire measurement instrument (or measurement protocol) was repeated or only part of it. We explain how these choices determine how intraclass correlation coefficients and standard errors of measurement formulas are built for different designs by using Venn diagrams. Strategies for improving the measurement are explained, and recommendations for reporting the essentials of these studies are described. We hope that this paper will facilitate the understanding and improve the design, analysis, and reporting of future studies on reliability and measurement error of measurements.

Reference values for the cross-sectional area of the lumbar multifidus muscle in children

BACKGROUND

The multifidus muscle plays a major role in the growth and postural control of children. Therefore, the reference values of the cross-sectional area (CSA) of the lumbar multifidus muscle represent an important tool for assessing muscle development and the early monitoring of musculoskeletal disorders.

OBJECTIVE

The aim of this study was to provide percentile scores for the CSA of the lumbar multifidus muscle in eutrophic children aged 5 to 10 years.

METHODS

This was a cross-sectional, observational study, involving 736 children. An anthropometric assessment was conducted and ultrasound (US) imaging was used to assess the CSA of the lumbar (vertebral level L5) multifidus muscle. The CSA was expressed as percentile scores.

RESULTS

The CSA in the boys ranged from 1.8 cm2 to 5.3 cm2 and in girls from 1.9 cm2 to 5.9 cm. The CSA in the 50th percentile scores of both sexes was 3.4 cm2. There was an increase in the CSA between 5 and 7 years old in both sexes. The CSA presented a greater variance in girls than in boys. After 8 years of age, the multifidus CSA increased in girls and decreased in boys.

CONCLUSION

The present study has provided percentile scores for the CSA of the lumbar multifidus muscle for eutrophic children aged 5 to 10 years. An increase was observed of the CSA of the multifidus muscle between the ages of 5 and 7 years and there were no differences in the CSA percentiles in relation to sex. An increase in the CSA after 8 years of age was only observed in the girls.

Correlation between Body Composition and Inter-Examiner Errors for Assessing Lumbar Multifidus Muscle Size, Shape and Quality Metrics with Ultrasound Imaging

Ultrasound imaging (US) is widely used in several healthcare disciplines (including physiotherapy) for assessing multiple muscle metrics such as muscle morphology and quality. Since measuring instruments are required to demonstrate their reliability, accuracy, sensitivity, and specificity prior to their use in clinical and research settings, identifying factors affecting their diagnostic accuracy is essential. Since previous studies analyzed the impact of sociodemographic but not body composition characteristics in US errors, this study aimed to assess whether body composition metrics are correlated with ultrasound measurement errors. B-mode images of the lumbar multifidus muscle at the fifth lumbar vertebral level (L5) were acquired and analyzed in 49 healthy volunteers by two examiners (one experienced and one novel). Cross-sectional area, muscle perimeter and mean echo intensity were calculated bilaterally. A multivariate correlation matrix was calculated for assessing the inter-examiner differences with body composition metrics. Results demonstrated excellent reliability (intraclass correlation coefficient, ICC > 0.9) for assessing the muscle cross-sectional area and perimeter, and good reliability for assessing the muscle shape and mean echo intensity (ICC > 0.7). Inter-examiner errors for estimating muscle size were correlated with participants' age (p value, p < 0.01), weight (p < 0.05), total and trunk lean mass (both, p < 0.01) and water volume (p < 0.05). Greater shape descriptors and mean brightness disagreements were correlated with older ages (p < 0.05) and total lean mass (p < 0.05). No correlations between age and body composition metrics were found (p > 0.05). This study found US to be a reliable tool for assessing muscle size, shape and mean brightness. Although aging showed no correlations with body composition changes in this sample, it was the main factor correlated with US measurement errors.

The effects of combined motor control and isolated extensor strengthening versus general exercise on paraspinal muscle morphology and function in patients with chronic low back pain: a randomised controlled trial protocol

BACKGROUND

Exercise is a common approach for the management of patients with chronic non-specific low back pain (LBP). However, there is no clear mechanistic evidence or consensus on what type of exercise is more effective than others. While considerable evidence suggests a link between lumbar muscle health (e.g., atrophy and fatty infiltration) with functional deficits, it is unknown whether exercises targeting the lumbar spine can lead to noticeable improvements in muscle health and functional outcomes. The primary aim of this study is to compare the effect of combined motor control and isolated strengthening lumbar exercises (MC + ILEX) versus a general exercise group (GE) on multifidus muscle morphology (size and composition). Secondary aims include assessing the effect of the interventions on overall paraspinal muscle health, pain and disability, as well as psychological factors as possible effect modifiers.

METHODS

A total of 50 participants with chronic non-specific LBP and moderate to severe disability, aged between 18 and 60, will be recruited from the local orthopaedic clinics and university community. Participants will be randomised (1:1) to either the MC + ILEX or GE group. Participants will undergo 24 individually supervised exercise sessions over a 12-week period. The primary outcome will be multifidus morphology (atrophy) and composition (fatty infiltration). Secondary outcomes will be muscle function (e.g., % thickness change during contraction), morphology, lumbar extension strength, pain intensity and disability. Potential treatment effect modifiers including maladaptive cognitions (fear of movement, catastrophizing), anxiety, depression, physical activity, and sleep quality will also be assessed. All measurements will be obtained at baseline, 6-week and 12-week; self-reported outcomes will also be collected at 24-week. Between-subjects repeated measure analysis of variance will be used to examine the changes in paraspinal muscle morphology over the different time points. Linear mixed models will be used to assess whether baseline scores can modify the response to the exercise therapy treatment.

DISCUSSION

The results of this study will help clarify which of these two common interventions promote better results in terms of overall paraspinal muscle heath, back pain, disability and psychological factors in adults with chronic LBP.

TRIAL REGISTRATION

NTCT04257253 , registered prospectively on February 5, 2020.

Ultrasound Imaging Analysis of the Lumbar Multifidus Muscle Echo Intensity: Intra-Rater and Inter-Rater Reliability of a Novice and an Experienced Rater

Background and Objectives: Ultrasound echo intensity (EI) of the lumbar multifidus muscle (LMM) could offer valuable insights regarding muscle quality in people with low back pain (LBP). However, whether the rater’s experience noticeably influences the reliability and precision of LMM EI measurements has not been established. The aims of this study were to investigate the intra-rater and inter-rater reliability of LMM EI measurements, and to compare the reliability and SEM between a novice and an experienced rater. Materials and Methods: Twenty athletes (10 females, 10 males) with a history of LBP were included in this study. Transverse ultrasound images of LMM were taken at L5 in prone. LMM EI measurements were obtained bilaterally by tracing the maximum ROI representing the LMM cross-sectional area (CSA), avoiding the inclusion of bone or surrounding fascia. All measurements were performed by two novice raters and an experienced researcher. Each measurement was acquired by each rater three times for each side on three different images, and the average was used in the analyses. Raters were blinded to each other’s measurements and the participant’s clinical information. Intra-class correlation coefficients (ICCs) were obtained to assess the intra-rater and inter-rater reliability. Results: The intra-rater ICC values for the LMM measurements for the experienced rater were excellent (ICC all > 0.997). The inter-rater reliability ICC values showed moderate to excellent reliability (0.614 to 0.994) and agreement between the novice raters and the experienced rater, except for Novice 1 for the right LMM, which revealed lower ICCs and a wider 95% CI. Intra-rater and inter-rater reliability results were similar when separately looking at the right and left side of the muscle and participant gender. Conclusions: Our findings support the clinical use of ultrasound imaging for the assessment of LMM EI in individuals with LBP.

Seasonal Changes in Lumbar Multifidus Muscle in University Rugby Players

PURPOSE

Although smaller lumbar multifidus muscle (LMM) was reported to be a strong predictor of lower limb injury (LLI) in Australian Football League players, LMM morphology has not been investigated in rugby athletes. This study examined seasonal changes in LMM in rugby players and whether LMM characteristics were associated with low back pain (LBP) and LLI.

METHODS

Ultrasound examinations of the LMM were acquired in 21 university-level rugby players (12 women, 9 men) at preseason and end-season. LMM cross-sectional area (CSA), thickness at rest, and thickness during submaximal contraction (e.g., contralateral arm lift) measurements in prone and standing were obtained bilaterally at the L5-S1 level. The percent change in LMM thickness during contraction was calculated as follows: [(thicknesscontracted - thicknessrest)/thicknessrest × 100]. Self-reported questionnaires were used to acquire data on LBP and LLI.

RESULTS

There was no significant difference in LMM characteristics between preseason and end-season measurements (P > 0.05). Preseason LMM CSA, side-to-side CSA asymmetry, and thickness at rest or during contraction were not associated with LBP or LLI. However, a lower percent thickness change in the standing position was significantly associated with having LBP during the preseason (P = 0.01) and playing season (P = 0.001), as well as LLI during the preseason (P = 0.03).

CONCLUSIONS

This study provides preliminary evidence that LMM contractile ability and behavior during functional movement, such as standing, may have important implications for the susceptibility to injury among rugby athletes.

Ultrasonography of Lumbar Multifidus Muscle in University American Football Players

PURPOSE

The primary objective of this study was to examine and compare lumbar multifidus (LM) muscle size, asymmetry, and function in university football players with and without low back pain (LBP). A secondary objective was to examine the relationship between LM characteristics and body composition in football players.

METHODS

Ultrasound assessments of the LM muscle were performed in 41 university football players during the preseason. LM muscle cross-sectional area, echo intensity (e.g., indicator of fatty infiltration and connective tissue), thickness at rest, and thickness during submaximal contraction (e.g., contralateral arm lift) measurements in prone and standing positions were obtained bilaterally at the L5-S1 level. Body composition measures were acquired using dual-energy x-ray absorptiometry. A self-administered questionnaire was used to obtain LBP history data.

RESULTS

The LM muscle thickness at rest in prone and in standing was significantly smaller in football players who reported the presence of LBP in the previous 3 months. The LM cross-sectional area in prone was significantly and positively correlated with weight, height, lean body mass, total fat mass, and total percent body fat. LM echo intensity was strongly correlated with total percent body fat and total fat mass and negatively correlated with the percent thickness change during contraction.

CONCLUSION

The results of this study provide novel information on LM muscle morphology and activation in football players in prone and standing and suggest that players with LBP in the previous 3 months had smaller LM muscle thickness. LM morphology was strongly correlated with body composition measurements.

LUMINOUS database: lumbar multifidus muscle segmentation from ultrasound images

BACKGROUND

Among the paraspinal muscles, the structure and function of the lumbar multifidus (LM) has become of great interest to researchers and clinicians involved in lower back pain and muscle rehabilitation. Ultrasound (US) imaging of the LM muscle is a useful clinical tool which can be used in the assessment of muscle morphology and function. US is widely used due to its portability, cost-effectiveness, and ease-of-use. In order to assess muscle function, quantitative information of the LM must be extracted from the US image by means of manual segmentation. However, manual segmentation requires a higher level of training and experience and is characterized by a level of difficulty and subjectivity associated with image interpretation. Thus, the development of automated segmentation methods is warranted and would strongly benefit clinicians and researchers. The aim of this study is to provide a database which will contribute to the development of automated segmentation algorithms of the LM.

CONSTRUCTION AND CONTENT

This database provides the US ground truth of the left and right LM muscles at the L5 level (in prone and standing positions) of 109 young athletic adults involved in Concordia University's varsity teams. The LUMINOUS database contains the US images with their corresponding manually segmented binary masks, serving as the ground truth. The purpose of the database is to enable development and validation of deep learning algorithms used for automatic segmentation tasks related to the assessment of the LM cross-sectional area (CSA) and echo intensity (EI). The LUMINOUS database is publicly available at http://data.sonography.ai .

CONCLUSION

The development of automated segmentation algorithms based on this database will promote the standardization of LM measurements and facilitate comparison among studies. Moreover, it can accelerate the clinical implementation of quantitative muscle assessment in clinical and research settings.

Effects of the Russian current in the treatment of low back pain in women: A randomized clinical trial

BACKGROUND

Low back pain (LBP) is a high impact condition that affects the working population, generating social and economic repercussions, the most relevant symptoms being pain and functional disability. Conservative treatment is often based on stabilizing spinal muscles with exercises: the Russian current (RC) is reported as an alternative, because it promotes muscle contraction, providing muscle strengthening and hypertrophy.

OBJECTIVE

To assess the effectiveness of the RC in aiding the treatment of low back pain.

METHODS

This randomized study included 23 women aged 18-30 years, divided into two groups: the control group (CG) and the Russian current group (RCG), for four weeks. Pain (visual analogue scale, VAS; pressure algometer, PA), function (Oswestry Low Back Disability Index), resistance (trunk resistance [TR] test) and thickness changes in the muscle (ultrasound image) were evaluated before and after the RC protocol and at one-month follow-up.

RESULTS

There were significant VAS reductions in both groups, but at follow-up these had only been maintained in the RCG, which presented lower values than the CG in the second evaluation. For PA, Oswestry and TR, there were differences only in the RCG. In a comparison of LBP between the groups, the initial difference disappeared in subsequent evaluations; TR presented higher values in evaluation 2 and 3 in the RCG group. In terms of thickness changes, differences between the groups were reduced after treatment.

CONCLUSION

The proposed treatment was effective in the reduction of LBP, with short-term improvement in resistance and thickness changes of the multifidus.

Inconsistent descriptions of lumbar multifidus morphology: A scoping review

Background

Lumbar multifidus (LM) is regarded as the major stabilizing muscle of the spine. The effects of exercise therapy in low back pain (LBP) are attributed to this muscle. A current literature review is warranted, however, given the complexity of LM morphology and the inconsistency of anatomical descriptions in the literature.

Methods

Scoping review of studies on LM morphology including major anatomy atlases. All relevant studies were searched in PubMed (Medline) and EMBASE until June 2019. Anatomy atlases were retrieved from multiple university libraries and online. All studies and atlases were screened for the following LM parameters: location, imaging methods, spine levels, muscle trajectory, muscle thickness, cross-sectional area, and diameter. The quality of the studies and atlases was also assessed using a five-item evaluation system.

Results

In all, 303 studies and 19 anatomy atlases were included in this review. In most studies, LM morphology was determined by MRI, ultrasound imaging, or drawings – particularly for levels L4–S1. In 153 studies, LM is described as a superficial muscle only, in 72 studies as a deep muscle only, and in 35 studies as both superficial and deep. Anatomy atlases predominantly depict LM as a deep muscle covered by the erector spinae and thoracolumbar fascia. About 42% of the studies had high quality scores, with 39% having moderate scores and 19% having low scores. The quality of figures in anatomy atlases was ranked as high in one atlas, moderate in 15 atlases, and low in 3 atlases.

Discussion

Anatomical studies of LM exhibit inconsistent findings, describing its location as superficial (50%), deep (25%), or both (12%). This is in sharp contrast to anatomy atlases, which depict LM predominantly as deep muscle. Within the limitations of the self-developed quality-assessment tool, high-quality scores were identified in a majority of studies (42%), but in only one anatomy atlas.

Conclusions

We identified a lack of standardization in the depiction and description of LM morphology. This could affect the precise understanding of its role in background and therapy in LBP patients. Standardization of research methodology on LM morphology is recommended. Anatomy atlases should be updated on LM morphology.

The Relationship Between Trunk Muscle Thickness and Static Postural Balance in Older Adults

Trunk muscles are required for safety of movement in aging. The authors aimed to investigate the relationship between trunk muscle thickness and the static postural balance in older adults. A total of 31 females and 23 males with a mean age of 73.39 ± 6.09 completed the study. The thickness of the trunk muscles was determined with ultrasound imaging. Postural balance was assessed with force plate. There was a positive weak correlation between right and left upper rectus abdominis muscle thickness and anterior stability area (p < .05, r > .3). The negative and moderate correlation was determined between the left lower rectus abdominis and the perturbated stability sway value (p < .01, r > .5). The increase in trunk muscle thickness in older adults increases the postural stability area and decreases the postural sway especially in the mediolateral direction.

The effect of low back pain and lower limb injury on lumbar multifidus muscle morphology and function in university soccer players

Background

The lumbar multifidus muscle (LMM) plays a critical role to stabilize the spine. While low back pain (LBP) is a common complaint in soccer players, few studies have examined LMM characteristics in this athletic population and their possible associations with LBP and lower limb injury. Therefore, the purpose of this study was to 1) investigate LMM characteristics in university soccer players and their potential association with LBP and lower limb injury; 2) examine the relationship between LMM characteristics and body composition measurements; and 3) examine seasonal changes in LMM characteristics.

Methods

LMM ultrasound assessments were acquired in 27 soccer players (12 females, 15 males) from Concordia University during the preseason and assessments were repeated in 18 players at the end of the season. LMM cross-sectional area (CSA), echo-intensity and thickness at rest and during contraction (e.g. function) were assessed bilaterally in prone and standing positions, at the L5-S1 spinal level. A self-reported questionnaire was used to assess the history of LBP and lower limb injury. Dual-energy x-ray absorptiometry (DEXA) was used to acquire body composition measurements.

Results

Side-to-side asymmetry of the LMM was significantly greater in males (p = 0.02). LMM thickness when contracted in the prone position (p = 0.04) and LMM CSA in standing (p = 0.02) were also significantly greater on the left side in male players. The LMM % thickness change during contraction in the prone position was significantly greater in players who reported having LBP in the previous 3-months (p < 0.001). LMM CSA (r = − 0.41, p = 0.01) and echo-intensity (r = 0.69, p < 0.001) were positively correlated to total % body fat. There was a small decrease in LMM thickness at rest in the prone position over the course of the season (p = 0.03).

Conclusions

The greater LMM contraction in players with LBP may be a maladaptive strategy to splint and project the spine. LMM morphology measurements were correlated to body composition. The results provide new insights with regards to LMM morphology and activation in soccer players and their associations with injury and body composition measurements.

The analgesic action of Aussie current in women with non-specific chronic lumbar pain

Background/aims

Despite electrostimulation being a common adjuvant therapy for non-specific low back pain, the use of Aussie current for muscle contraction is still underreported in the literature. The present study aimed to assess the use of Aussie current in the treatment of chronic, non-specific lumbar pain.

Methods

Twenty-four young women with chronic non-specific low back pain were randomly assigned to the Aussie current group or control group. Pain (visual analogue scale and McGill Pain Questionnaire), function (Oswestry Disability Index), trunk muscle resistance (the time the participant remained in a predefined static position) and multifidus muscle thickness (ultrasound images) were analysed bilaterally before, at the end of and 30 days after completing the treatment protocol. The treatment group received 12 sessions of Aussie current over a period of 4 weeks. The electrodes were arranged laterally and bilaterally to the spinous processes of the first and fifth lumbar vertebrae.

Results

There was a reduction in the pain profile for the Aussie group, as measured by a visual analogue scale and the McGill Pain Questionnaire. There was an increase in trunk muscle resistance and in muscle thickness in the Aussie group when compared to the control group. There were no changes in the Oswestry Disability Index in either group.

Conclusions

Aussie current resulted in significant improvements in pain, endurance and muscle thickness in women with chronic, non-specific low back pain.

Ultrasonography of multifidus muscle morphology and function in ice hockey players with and without low back pain

OBJECTIVES

To examine the relationship between lumbar multifidus (LM) morphology, function, echo-intensity (EI) and body composition among a group of university level ice hockey players with and without low back pain (LBP).

DESIGN

Cross-sectional study.

SETTING

University Research Centre.

PARTICIPANTS

Thirty-two hockey players (18 females, 14 males) participated in this study.

MAIN OUTCOME MEASURES

Resting LM cross-sectional area (CSA) was assessed bilaterally at the L5 level in prone and standing using ultrasound imaging. The LM thickness at rest and during contraction was evaluated in addition to LM EI. Body composition measures were acquired using dual-energy X-ray absorptiometry (DEXA) and LBP history was acquired using a self-reported questionnaire.

RESULTS

LM muscle CSA was significantly associated with body composition measurements. LM EI was strongly associated with total % body fat and significantly greater in females. Resting LM muscle CSA and thickness (prone) was significantly smaller in players with LBP 4-weeks prior. LM side-to-side asymmetry (standing) was also significantly greater in players with LBP 3-months prior.

CONCLUSION

The results provide new insights with regards to LM morphology and activation in ice hockey players and revealed specific deficits in LM morphology in athletes with LBP. LM morphology was strongly associated with body composition measurements.

Immediate Effect of Lumbar Mobilization on Activity of Erector Spinae and Lumbar Multifidus Muscles

Objective

The purpose of this study was to investigate the effect of grade IV lumbar mobilization on the activity/contraction of erector spinae (ES) and lumbar multifidus (LM) muscles in healthy people.

Methods

A randomized, repeated-measures design was used. Sixteen healthy subjects attended 3 testing sessions with a different intervention in each session (no intervention, grade IV central lumbar mobilization at L4, and placebo/light touch). Lying in a prone position, subjects lifted a light weight with their right arm while ultrasound images of LM and surface electromyography signals of ES were captured before and immediately after application of the intervention in the session. The contraction of LM was calculated from US images, and the root mean square was calculated from the electromyography signals of ES and used as outcome measures.

Results

A significant difference was found in LM contraction between the placebo and mobilization intervention (difference = 0.04, P = .02). There was no difference for the root mean square of electromyography signals between the interventions.

Conclusion

The significant difference in LM contraction was small and may not have clinical significance. Lumbar mobilization did not change the activity of ES in healthy people. Future studies with larger samples are needed to confirm our findings and to investigate the effect of mobilization on back muscles in people with low back pain.

Musculoskeletal diagnostic ultrasound imaging for thickness measurement of four principal muscles of the cervical spine -a reliability and agreement study

BACKGROUND

The reliability of musculoskeletal diagnostic ultrasound imaging (MSK-DUSI) for the evaluation of neck musculature has been sparsely documented in the research literature. Until now, research has featured a limited number of subjects and only few studies have tested for both inter- and intra-reliability using appropriate methodology.

METHODS

Four examiners conducted an inter- and intra-rater reliability and agreement study. Fifty females with and without neck pain (NP) between the ages of 20-70 were recruited from October 2014 to April 2015. The muscles that were evaluated were the longus colli (Lcol), the rectus capitis posterior major (Rcpm), the deep cervical extensors (Dce) and the semispinalis capitis (Sscap). Each of the examiners captured ultrasound images of their allocated muscle and measured the thickness of that muscle twice, on separate occasions, for the first part of the intra-rater reliability study. For the second part, a second image of the same muscle was taken on the same subject and measured by the same examiner. The four examiners then met to measure on each other's images, to test inter-rater reliability. Their results were compared pair-wise using Interclass Correlation Coefficients (ICC) and Bland-Altman plots. Linear regression analysis was performed to evaluate for possible bias.

RESULTS

Inter-rater reliability was found to be good for Lcol and Sscap muscles and moderate towards poor for the deeper Rcpm and Dce muscles. Intra-rater reliability was good for all the muscles, with the exception of the Dce, which was found to be moderate in the second part of the study. The B&A plots showed good agreement, few outliers, and no bias. However, the agreement intervals indicated a measurement error within the variance of the method that may not have been acceptable for these small muscles if the aim is to evaluate change in thickness.

CONCLUSIONS

This study found that MSK-DUSI had variable reliability in assessing the thickness of the Lcol, Rcpm, Dce, and Sscap muscles. No bias was demonstrated, but agreement intervals were wide.

Estimation of spinopelvic muscles' volumes in young asymptomatic subjects: a quantitative analysis

PURPOSE

Muscles have been proved to be a major component in postural regulation during pathological evolution or aging. Particularly, spinopelvic muscles are recruited for compensatory mechanisms such as pelvic retroversion, or knee flexion. Change in muscles' volume could, therefore, be a marker of greater postural degradation. Yet, it is difficult to interpret spinopelvic muscular degradation as there are few reported values for young asymptomatic adults to compare to. The objective was to provide such reference values on spinopelvic muscles. A model predicting the muscular volume from reduced set of MRI segmented images was investigated.

METHODS

A total of 23 asymptomatic subjects younger than 24 years old underwent an MRI acquisition from T12 to the knee. Spinopelvic muscles were segmented to obtain an accurate 3D reconstruction, allowing precise computation of muscle's volume. A model computing the volume of muscular groups from less than six MRI segmented slices was investigated.

RESULTS

Baseline values have been reported in tables. For all muscles, invariance was found for the shape factor [ratio of volume over (area times length): SD < 0.04] and volume ratio over total volume (SD < 1.2 %). A model computing the muscular volume from a combination of two to five slices has been evaluated. The five-slices model prediction error (in  % of the real volume from 3D reconstruction) ranged from 6 % (knee flexors and extensors and spine flexors) to 11 % (spine extensors).

CONCLUSION

Spinopelvic muscles' values for a reference population have been reported. A new model predicting the muscles' volumes from a reduced set of MRI slices is proposed. While this model still needs to be validated on other populations, the current study appears promising for clinical use to determine, quantitatively, the muscular degradation.