Predictors of isokinetic back muscle strength in patients with low back pain

Musculoskeletal Dimension and Brightness Reference Values in Lumbar Magnetic Resonance Imaging-A Radio-Anatomic Investigation in 80 Healthy Adult Individuals

Background/Objectives: Magnetic resonance imaging (MRI) is the preferred diagnostic means to visualize spinal pathologies, and offers the possibility of precise structural tissue analysis. However, knowledge about MRI-based measurements of physiological cross-sectional musculoskeletal dimensions and associated tissue-specific average structural brightness in the lumbar spine of healthy young women and men is scarce. The current study was planned to investigate characteristic intersexual differences and to provide MRI-related musculoskeletal baseline values before the onset of biological aging. Methods: At a single medical center, lumbar MRI scans of 40 women and 40 men aged 20-40 years who presented with moderate nonspecific low back pain were retrospectively evaluated for sex-specific differences in cross-sectional sizes of the fifth lumbar vertebrae, psoas and posterior paravertebral muscles, and respective sex- and age-dependent average brightness alterations on T2-weighted axial sections in the L5-level. Results: In women (mean age 33.5 years ± 5.0 (standard deviation)), the investigated musculoskeletal cross-sectional area sizes were significantly smaller (p < 0.001) compared to those in men (mean age 33.0 years ± 5.7). Respective average musculoskeletal brightness values were higher in women compared to those in men, and most pronounced in posterior paravertebral muscles (p < 0.001). By correlating brightness results to those of subcutaneous fat tissue, all intersexual differences, including those between fifth lumbar vertebrae and psoas muscles, turned out to be statistically significant. This phenomenon was least pronounced in psoas muscles. Conclusions: Lumbar musculoskeletal parameters showed significantly larger dimensions of investigated anatomical structures in men compared to those in women aged 20-40 years, and an earlier onset and faster progress of bone loss and muscle degradation in women.

The importance of psoas muscle on low back pain: a single-center study on lumbar spine MRI

Background

Low back pain (LBP) is the most frequent indication to magnetic resonance imaging (MRI) examinations of the lumbosacral spine. The individual role of soft tissues, including muscles, on LBP is not fully understood and the contribution of each MRI-derived parameter of soft tissues status on the intensity of LBP has not been investigated in detail.

Methods

The study design was observational retrospective, single center carried out at a University Hospital. Images were acquired using a using a 1.5 Tesla scanner. Patients completed a symptom questionnaire and rated their pain intensity using the Visual Analogue Scale (VAS). The VAS scores ​​were categorized as mild, moderate, and severe using cutoff values of 3.8 and 5.7, based on the literature. Biometric data, including weight and height, were also recorded to calculate the body mass index (BMI). The ratios between intramuscular fat infiltration and net muscle area were also calculated. Patient sample included 94 patients with LBP underwent MRI of the lumbosacral spine.

Results

The stepwise analysis revealed that increasing psoas net area was associated with lower VAS levels (odds ratio [OR]: 0.94: 95% confidence interval [CI]: 0.90-0.98; p=.005), and an increase of one square centimeter of total psoas area resulted in a greater probability of reporting a mild (+1.21%; 95% CI: 0.37, 2.05%) or a moderate VAS (+0.40%; 95% CI: -0.02, 0.82%), Furthermore, a more severe VAS was associated with a higher BMI (OR: 1.13; 95% CI: 1.00-1.27).

Conclusion

Our study demonstrates a relationship between LBP and MRI parameters of paravertebral and psoas muscles status. The psoas muscle is extremely important for spine stabilization and is linked to clinical symptoms of patients affected by LBP. These findings could contribute to future studies and improve treatment options in patients with LBP, possibly reducing the impact on disability, quality of life and socioeconomical burden.

Human primary myoblasts derived from paraspinal muscle reflect donor age as an experimental model of sarcopenia

BACKGROUND

Low back pain is a general phenomenon of aging, and surgery is an unavoidable choice to relieve severe back pain. The discarded surgical site during surgery is of high value for muscle and muscle-related research. This study investigated the age-dependent properties of patients' paraspinal muscles at the cellular level.

METHODS

To define an association of paraspinal muscle degeneration with sarcopenia, we analyzed lumbar paraspinal muscle and myoblasts isolated from donors of various ages (25-77 years). Preoperative evaluations were performed by bioimpedance analysis using the InBody 720, magnetic resonance (MR) imaging of the lumbar spine, and lumbar extension strength using a lumbar extension dynamometer. In addition, the growth and differentiation capacity of myoblasts obtained from the donor was determined using proliferation assay and western blotting.

RESULTS

The cross-sectional area of the lumbar paraspinal muscle decreased with age and was also correlated with the appendicular skeletal muscle index (ASM/height2). Human primary myoblasts isolated from paraspinal muscle preserved their proliferative capacity in vitro, which tended to decrease with donor age. The age-dependent decline in myoblast proliferation was correlated with levels of cell cycle inhibitory proteins (p16INK4a, p21CIP1, and p27KIP1) associated with cellular senescence. Primary myoblasts isolated from younger donors differentiated into multinucleate myotubes earlier and at a higher rate than those from older donors in vitro. Age-dependent decline in myogenic potential of the isolated primary myoblasts was likely correlated with the inactivation of myogenic transcription factors such as MyoD, myogenin, and MEF2c.

CONCLUSIONS

Myoblasts isolated from human paraspinal muscle preserve myogenic potential that correlates with donor age, providing an in vitro model of sarcopenia.

Reduced volume and altered composition of paraspinal muscles in Marfan syndrome: A retrospective cohort study

Retrospective cohort study. Spinal deformities in patients with Marfan syndrome (MFS) are distinct from those in patients with idiopathic scoliosis (IS). It is more prone to progression and more likely to present with sagittal malalignment than IS. However, the etiology of this characteristic spinal deformity in MFS remains unclear. This study aimed to determine the spinal musculature characteristics in patients with MFS on the hypothesis that the paraspinal muscles of patients with MFS would be qualitatively or quantitatively different from those of patients with IS. Seventeen consecutive patients with MFS aged 25 years or younger undergoing surgery for scoliosis in our hospital were compared with age- and sex-matched patients with IS undergoing surgery for scoliosis. The body size-adjusted relative cross-sectional area (rCSA), fatty infiltration ratio (FI%), and relative functional cross-sectional area (rFCSA) of the psoas muscles (PM) and paravertebral muscles (PVM) at L3/4 and L4/5 were measured using preoperative T2-weighted magnetic resonance imaging. Functional CSA was defined as total CSA minus the fatty infiltration area of each muscle and rFCSA was calculated as the body size-adjusted functional CSA. The rCSA of the PM at L3/4 and L4/5 was significantly smaller in the MFS group than in the IS group (L3/4, P = .021; L4/5, P = .002). The FI% of the PM at L4/5 was significantly higher in the MFS group (P = .044). Consequently, the rFCSA of the PM at L3/4 and L4/5 and the rFCSA of the PVM at L3/4 in the MFS group were significantly smaller than those in the IS group (PM at L3/4, P = .021; PM at L4/5, P = .001; PVM at L3/4, P = .025). Compared with patients with IS, patients with MFS exhibited significantly decreased body-size-adjusted CSA of the PM and reduced body-size-adjusted functional CSA of the PVM and PM. These findings may partially explain the characteristics of distinctive spinal deformities in patients with MFS.

Relationship between body mass index and spinal pathology in community-dwelling older adults

PURPOSE

To clarify the relationship between body mass index (BMI) and spinal pathologies including spinal sagittal balance, back extensor strength (BES), paraspinal muscle mass, prevalent vertebral fracture, disc degeneration, Modic changes, low back pain, and quality of life (QOL) in community-dwelling older adults.

METHODS

This study included 380 participants (age: ≥ 65 years, male/female: 152/228) from the Shiraniwa Study. Multivariate nonlinear regression analysis was used to investigate the relationship between BMI and sagittal vertical axis (SVA), BES, paraspinal muscle mass, visual analog scale (VAS) for low back pain, Oswestry Disability Index (ODI), and EuroQoL-5 Dimension (EQ5D) score after adjusting for sex, age, Hospital Anxiety and Depression Scale score, and Charlson Comorbidity Index. In addition, multiple logistic regression analysis was used to investigate the association between BMI and prevalent vertebral fracture, disc degeneration, and Modic changes.

RESULTS

BMI was significantly correlated with SVA, BES, paraspinal muscle mass, VAS, ODI, and EQ5D score. The increase in BMI was associated with the deterioration of all outcomes, which accelerated when the BMI increased from approximately 22-23 kg/m². Moreover, overweight/obesity was significantly correlated with disc degeneration and Modic changes.

CONCLUSION

Increased BMI is significantly associated with spinal pathologies such as SVA, BES, paraspinal muscle mass, VAS, QOL, disc degeneration, and Modic changes. The findings suggest that measures for controlling overweight and obesity among older adults can play an important role in the prevention and treatment of spinal pathologies.

The Relationship Between Pain-Related Psychological Factors and Maximal Physical Performance in Low Back Pain: A Systematic Review and Meta-Analysis

Theoretical frameworks explain how pain-related psychological factors may influence the physical performance. In this systematic review and meta-analysis, we evaluated the evidence regarding the relationship between the pain-related psychological factors and the maximal physical performance in patients with low back pain (LBP). Pubmed, Embase, CINAHL and Web of Science databases were searched from inception to May 2022. Cross-sectional or longitudinal studies reporting cross-sectional measures of association between at least one pain-related psychological factor and a quantitatively measured outcome of maximal physical performance in patients with LBP were eligible for inclusion. Thirty-eight studies (n = 2,490; 27 cross-sectional studies, n = 1,647 (66%); 11 longitudinal studies, n = 843 (34%)) were included, with 92% of participants (n = 2,284) having chronic LBP. Results showed that pain-related fear, pain catastrophizing, and anticipated pain were consistently and negatively associated with the maximal physical performance in chronic LBP, whereas pain-self efficacy showed positive correlations. Overall, magnitudes of absolute pooled r-values were small (r ≤ 0.25), except for anticipated pain, which was moderately associated with maximal physical performance (r = -0.34 to -0.37). Subanalyses and sensitivity analyses yielded similar pooled correlation coefficients. Certainty of evidence using the GRADE recommendations was very low to moderate for pain-related fear, and very low to low for the other pain-related psychological factors. Prospero registration: CRD42021227486. PERSPECTIVE: Overall, small pooled correlation coefficients were shown between pain-related psychological factors and maximal physical performance in chronic LBP. Certainty of evidence was very low to low for all pain-related psychological factors other than pain-related fear. Future studies taking into account limitations of the current literature may therefore change these conclusions.

Five Times Sit-to-Stand Test in people with non-specific chronic low back pain—a cross-sectional test–retest reliability study

PURPOSE/AIM

The Five Times Sit-to-Stand Test (FTSST) is a method that evaluates lower extremity muscle strength and balance level. The aim of this study is to test the validity and reliability of the FTSST in patients with non-specific chronic low back pain (NSCLBP) whose lower extremity muscle strength and balance levels are adversely affected.

METHODS

The first outcome measure of the study was the FTSST, which was conducted by two different researchers. Secondary outcome measures are Biodex Balance System (BBS), Quadriceps Muscle Strength Test, Oswestry Disability Index (ODI), and Visual Analogue Scale (VAS). Intraclass Correlation Coefficient (ICC) was used for the validity and reliability of the FTSST, which was made by two different researchers, and Pearson's Correlation Analysis was used to determine its relationship with other measurements.

RESULTS

Inter-rater and test-retest reliability for the FTSST were excellent (Intraclass Correlation Coefficient = 0.99). A statistically significant correlation was found between all secondary outcome measures (BBS, quadriceps muscle strength, ODI, VAS) and FTSST (p < 0.05).

CONCLUSION

In line with the findings of our study, we think that FTSST is a simple, easy, and reproducible method for evaluating lower extremity muscle strength, balance level, functional status, and pain in patients with NSCLBP.

Effect of Ultrasound-Guided Hydrorelease of the Multifidus Muscle on Acute Low Back Pain

OBJECTIVES

To examine improvement in acute low back pain (LBP) using ultrasound-guided hydrorelease of the multifidus muscle.

METHODS

This prognostic cohort study was conducted in a private clinic on samples of 75 patients with acute LBP diagnosed based on physical and imaging findings. Hydrorelease of the multifidus muscle was performed at the L4/5 level. The LBP visual analog scale (VAS) scores (cm) before and 5 minutes after hydrorelease were statistically evaluated. We defined improvement rate (%) as {LBP VAS scores (cm) immediately before hydrorelease - LBP VAS scores (cm) 5 minutes after hydrorelease} × 100 / LBP VAS scores (cm) immediately before hydrorelease and examined the correlation of the Heckmatt score and average age with the improvement rate.

RESULTS

LBP VAS scores (cm) before and 5 minutes after hydrorelease were 7.19 ± 1.01 (mean ± SD) and 2.85 ± 1.25, respectively (p < 0.05). No significant correlations were noted between the LBP improvement rate and the Heckmatt score or age. There were no gender variations in the improvement rate.

CONCLUSIONS

Ultrasound-guided hydrorelease of the multifidus muscle led to considerable LBP VAS score improvement at the outpatient level. The improvement rate showed no correlations with the Heckmatt score or age, and there were no significant gender variations in the improvement rate. Therefore, fatty degeneration of muscles and change in muscle echogenicity due to age and gender may not be associated with muscular LBP. These findings suggest that multifidus muscle hydrorelease could be useful in the diagnosis and treatment of acute LBP.

Isokinetic evaluation of the trunk flexors and extensors in women with and without scoliosis: A comparative study

BACKGROUND: Scoliosis affects mainly women and even if its diagnosis relies on clinical evaluation and radiographic assessment, muscular involvement is undeniable impacting possibly on strength and daily activities. OBJECTIVE: To assess the strength of sagitally operating trunk muscles in women with scoliosis (WwS) and apparently healthy women (AH) with a similar mean age. METHODS: The two groups consisted 114 WwS and 42 AH women. The concentric isokinetic evaluation related to the peak moment (PM) of the trunk flexors and extensors at 30 and 90∘/s. Division into subgroups was based on the location of the scoliosis and magnitude of the Cobb angle. RESULTS: The PM of both muscle groups was not correlated with the location of the scoliosis. However, these muscles manifested a highly significant weakness in WwS compared to the AH group, in both test velocities. In terms of the general severity of the weakness, the PM scores in WwS with Cobb angle > 30∘ were significantly lower compared to their healthy counterparts in both ‘muscle’ and ‘velocity’ whereas save the flexors at 90∘/s, there was no difference between the lesser compromised WwS (Cobb ⩽ 30∘) and AH women. The PM-based extension/flexion ratios in WwS were respectively 1.34 ± 0.28 and 1.23 ± 0.27 at 30∘/s and 90∘/s, with no significant difference between subgroups, nor with control values. CONCLUSION: In view of the results, trunk muscles strength should definitely be taken into account when planning therapeutic options for WwS.

Sarcopenia and Back Muscle Degeneration as Risk Factors for Degenerative Adult Spinal Deformity with Sagittal Imbalance and Degenerative Spinal Disease: A Comparative Study

BACKGROUND

Many factors affect spinal alignment in adult spinal deformity with sagittal imbalance. However, although the importance of the paravertebral muscle and ligamentum complex in proper spinal alignment is well recognized, little information is available regarding the role of the paravertebral muscles in maintaining sagittal spinal alignment.

METHODS

A total of 108 patients who had visited our institution from January 2016 to June 2018 were included in the present study. The patients were categorized as follows: degenerative adult spinal deformity with sagittal imbalance group and degenerative spinal disease group. The appendicular skeletal muscle mass index and handgrip strength of each patient were measured to evaluate for sarcopenia. Computed tomography was used to measure the cross-sectional area (CSA) and fat infiltration rate to evaluate paravertebral muscle morphology. The paravertebral muscle function was assessed by measuring the lumbar flexor strength and lumbar extensor strength using a lumbar isokinetic dynamometer.

RESULTS

The degenerative adult spinal deformity with sagittal imbalance group had a lower CSA index and lumbar extensor strength index and higher fat infiltration rate than the degenerative spinal disease group. No statistically significant differences in the appendicular skeletal muscle mass index and handgrip strength were found between the 2 groups. Only the CSA showed a correlation with the radiological parameters, such as pelvic tilt and lumbar lordosis.

CONCLUSIONS

Degeneration of the paravertebral muscle is a risk factor for degenerative adult spinal deformity with sagittal imbalance but not for sarcopenia. Thus, spinal sagittal imbalance is affected by isolated paravertebral muscle degeneration rather than by systemic muscle degeneration.

One versus two-handed lifting and lowering: lumbar spine loads and recommended one-handed limits protecting the lower back

The objectives of this study were to quantify loads imposed upon the lumbar spine while lifting/lowering with one versus two hands and to create guidelines for one-handed lifting/lowering that are protective of the lower back. Thirty subjects (15 male, 15 female) performed one- and two-handed exertions in a laboratory, lifting from/lowering to 18 lift origins/destinations using medicine balls of varying masses. An electromyography-assisted model predicted peak spinal loads, which were related to tissue tolerance limits to create recommended weight limits. Compared to two-handed exertions, one-handed exertions resulted in decreased spinal compression and A/P shear loading (p < 0.001) but increased lateral shear (p < 0.001). Effects were likely driven by altered moment exposures attributable to altered torso kinematics. Differences between spinal loads for one- versus two-handed exertions were influenced by asymmetry (p < 0.001) and amplified at lower lift origin/destination heights, lower object masses and larger horizontal distances between the body and the load (p < 0.001). Practitioner summary: A biomechanical model was utilised to compare spinal loading for one versus two-handed lifting/lowering. Spinal loads in compression and A/P shear were reduced for one-handed relative to two-handed exertions. As current lifting guidelines cannot appropriately be applied to one-handed scenarios, one-handed weight limits protecting the lower back are presented herein. Abbreviations: LBD: low back disorder, EMG: electromyography, A/P: anterior/posterior, MVC: maximum voluntary contraction.

Sarcopenia and Back Muscle Degeneration as Risk Factors for Back Pain: A Comparative Study

Study Design

Case-control study.

Purpose

To investigate the independent associations of back pain with sarcopenia and with back muscle degeneration, and to introduce a new risk index for back muscle degeneration.

Overview of Literature

The Asian Working Group for Sarcopenia recommends diagnosis using handgrip strength, gait speed, and skeletal muscle mass. However, these criteria do not strongly reflect back muscle degeneration.

Methods

Patients who completed a questionnaire on back-pain between October 2016 and October 2017 were enrolled in this study. Appendicular skeletal muscle index (ASMI), cross-sectional area (CSA) index, fatty infiltration (FI) rate of the paraspinal muscles, and lumbar extensor strength index (LESI) were measured and compared between no back-pain and back-pain group. Correlations between LESI and ASMI, CSA index, and FI rate were analyzed. The back-pain group was further divided according to ASMI into sarcopenia and non-sarcopenia subgroups and by our newly developed back muscle degeneration risk index based on correlation coefficients between LESI and CSA index, FI rate. Differences in ASMI, CSA index, FI rate, LESI, and Visual Analog Scale (VAS) score between subgroups were analyzed.

Results

The ASMI, CSA index, FI rate, and LESI differed significantly between back-pain and pain-free groups. The LESI demonstrated the strongest correlation with FI rate. There were no significant differences in VAS score and back muscle degeneration index in the back-pain group when divided according to the presence of sarcopenia. However, there was a significant difference in VAS score between back-pain patients when classified according to high and low back muscle degeneration risk index.

Conclusions

We suggest that the degree of back pain is more strongly associated with back muscle degeneration than with sarcopenia. This back muscle degeneration risk index, reflecting both back muscle morphology and function, could be a useful parameter for evaluation of back pain and muscle degeneration.

Changes in the macroscopic morphology of hip muscles in low back pain

Low back pain is a major health issue affecting the lumbopelvic muscles. Morphological changes in hip muscles, such as alterations in the muscle cross-sectional area and muscle volume, may occur in patients with low back pain. This systematic review was conducted to investigate whether patients with low back pain have macroscopic changes in their hip muscle morphology compared with asymptomatic, healthy individuals, based on current evidence. The electronic databases of PubMed/Medline, Ovid, Scopus, Embase^® , and Google Scholar were searched from the inception to August 31, 2018. We only included full texts of original studies regarding macroscopic morphological alterations, including atrophy and fat infiltration, in hip muscles of patients with low back pain compared with asymptomatic controls. The quality of the included studies was determined using an assessment tool based on the Newcastle-Ottawa Scale. The scale was modified for the purposes of this study. Sixteen comparative observational studies were found eligible to be included in this review. Eleven were classified as high quality and four as moderate quality. The morphological changes in the psoas major, gluteus maximus, gluteus medius, gluteus minimus, and piriformis muscles were assessed in the primary studies. All selected studies were considered B level of evidence studies. The strength of conclusions for the psoas major, gluteal, and piriformis muscles was moderate. The results revealed that there is substantial controversy about the morphological changes in hip muscles in patients with low back pain; however, the majority of high-quality studies concluded that atrophy of hip muscles is evident in patients with low back pain. The psoas major muscle was the most commonly investigated hip muscle for morphological changes. Major methodological limitations of the included studies were identified and discussed. The present systematic review does not include a formal meta-analysis because of very significant differences in the primary studies in terms of study populations and methodologies. Finally, in clinical practice, it is recommended that physical therapists develop exercise programs to improve hip muscle function in patients with low back pain.

Lumbar Extensor Muscle Size and Isometric Muscle Strength in Women with Symptomatic Lumbar Degenerative Diseases

Study Design

A cross-sectional design.

Purpose

To determine the characteristics of lumbar extensor muscle (LEM) size and isometric muscle strength and examine their correlations in women with lumbar degenerative diseases (LDDs).

Overview of Literature

Many studies have evaluated the relationship between muscle size and strength, but the results have been controversial.

Methods

Seventy-four female patients (mean age, 66 years) who consecutively underwent posterior lumbar interbody fusion (L1–S1) were recruited. The cross-sectional area (CSA) of the back extensor muscles was measured between L1–2 to L5–S1, and the total sum of the CSAs at each disc level was calculated. Back extensor muscle strength was evaluated using a MedX lumbar extension machine. The Oswestry Disability Index (ODI, 0–100) and Visual Analog Scale (VAS, 0–10) of lower back pain were determined.

Results

The mean CSAs of the LEM at each level (L1/2–L5/S1) and the total sum were 34.3, 36.3, 35.1, 31.4, 21.9, and 156.2 cm2, respectively. The mean isometric strength at each angle (range, 0°–72°) was 32.5, 50.1, 72.0, 88.7, 100.7, 112.2, and 126.2 ft-lb, respectively. The mean ODI and VAS scores were 54.6 and 6.6, and the mean body weight and body mass index (BMI) were 59.9 kg and 24.9 kg/m₂, respectively. The CSAs of the upper lumbar level (L1–4) and the total sum of the CSAs were associated with isometric strength, which was negatively correlated with patients’ age and ODI and positively associated with body weight and BMI, mainly at higher lumbar flexion angles (48°–72°).

Conclusions

In women with LDD, LEM sizes of the upper lumbar levels (L1–4) were larger than those of the lower levels (L4–S1) and were positively associated with muscle strength. The upper lumbar levels in patients with LDDs appear to play a compensatory role when degenerative lesions are present in the lower lumbar levels.

Criterion Validity of Ultrasound Imaging: Assessment of Multifidi Cross-Sectional Area in Older Adults With and Without Chronic Low Back Pain

BACKGROUND AND PURPOSE

Ultrasound (US) imaging may be a cost-conscious alternative to magnetic resonance imaging (MRI), which is the criterion standard for muscle cross-sectional area (CSA) assessment. Within the trunk, when compared with MRI, US has been shown to be valid for assessing lumbar multifidi CSA in younger, asymptomatic individuals. To date, there are no studies validating US for multifidi CSA assessment in older adults or individuals with low back pain. Given age- and pain-related muscle changes, validation of US is needed in these populations. If valid for multifidi CSA assessment, US may be used to evaluate short-term changes in muscle size in response to exercise-based interventions among older adults. The primary objective of this study was to evaluate the validity of US for multifidi CSA assessment as compared with MRI in older adults with and without chronic low back pain (CLBP). The secondary objective was to determine whether a single US image was valid for assessment of multifidi CSA or whether the average of 3 US images should be recommended.

METHODS

Twenty community-dwelling older adults (ie, 10 with and 10 without CLBP), ages 60 to 85 years, were recruited. US images and MRI slices of multifidi muscle were obtained and L4 multifidi CSAs were measured. Intraclass correlation coefficients (ICCs) were calculated to assess agreement between MRI measures and a single US image and MRI measures and the average of 3 US images.

RESULTS AND DISCUSSION

ICC point estimates were excellent for older adults with CLBP for a single US image (ICCs = 0.90-0.97), but ICC point estimates for participants without CLBP ranged from fair to excellent (ICCs = 0.48-0.86). ICC point estimates for the average of 3 US images for both groups were better than for a single image (ICCs = 0.95-0.99).

CONCLUSIONS

For assessment of L4 multifidi CSA, US is a valid alternative to MRI for older adults with and without CLBP. However, limitations of US, such as the inability to quantify intramuscular fat, which may be increased with aging and CLBP, should be considered. CSA measurement of 3 US images, rather than a single image, is recommended.

Relationships between vitamin D and paraspinal muscle: human data and experimental rat model analysis

BACKGROUND CONTEXT

Vitamin D deficiency (VDD) has been closely linked with skeletal muscle atrophy in many studies, but to date no study has focused on the paraspinal muscle.

PURPOSE

To verify paraspinal muscle changes according to serum vitamin D level.

STUDY DESIGN

A cross-sectional study of patients who visited our hospital and an in vivo animal study.

METHODS

We measured serum vitamin D concentration in 91 elderly women and stratified them according to their vitamin D status in three groups, control, vitamin D insufficiency, and VDD, and obtained magnetic resonance imaging data of the lumbar spine and evaluated the quality and quantity of the paraspinal muscles. Additionally, we designed experimental rat models for VDD and VDD replacement. Then, we analyzed the microcomputed tomography data and histologic data of paraspinal muscles, and the histologic data and reverse transcription-quantitative polymerase chain reaction data of intramyonuclear vitamin D receptor (VDR) in paraspinal muscle through comparison with control rats (n=25, each group). This work was supported by a Biomedical Research Institute grant ($40,000), Kyungpook National University Hospital (2014).

RESULTS

In the human studies, a significant decrease was noted in the overall paraspinal muscularity (p<.05) and increase in fatty infiltration in the VDD group as compared with the other groups (p<.05). In the rat experiment, a decrease was noted in paraspinal muscle fiber size and VDR concentration and VDR gene expression level, and total muscle volume of the VDD rats as compared with the control rats (p<.05). Vitamin D replacement after VDD could partially restore the muscle volume, muscle fiber size, and intramyonuclear VDR concentration levels (p<.05) of the paraspinal muscles.

CONCLUSIONS

VDD induces paraspinal muscle atrophy and decreases the intramyonuclear VDR concentration and VDR gene expression level in these muscles. Vitamin D replacement contributes to the recovery from atrophy and restoration of intramyonuclear VDR concentration in VDD status.

Do Older Adults and Those Recovered from Low Back Injury Share Common Muscle Activation Adaptations?

Theoretical models suggest trunk muscle activation compensates for spinal systems impairments. The purpose of this study was to determine if two populations (older adults and those recovered from a lower back injury (rLBI)) with spinal system impairments have similar muscle activation patterns to each other, but differ from controls. Trunk electromyograms collected from 12 older adults, 16 rLBI, and 19 controls during two dynamic tasks showed that older adults and rLBI had higher activation amplitudes, sustained temporal and more synergistic activation relative to controls. However, differences found between older adults and rLBI suggest that spinal system impairments differed between groups or that recent pain (rLBI) uniquely influenced muscle activation. This sheds light on our understanding of the relationship between spinal system impairments and muscle activation.

Paraspinal muscles density: a marker for degenerative lumbar spinal stenosis?

Background

The condition of paraspinal muscles is known to be associated with some variables such as age, gender, and low back pain. It is generally agreed that these muscles play an important role in the stability and functional movements of the lumbar vertebral column. Although spinal instability has been shown to play an essential role in degenerative lumbar spinal stenosis (DLSS), the role of paraspinal muscles remains elusive. The main purpose of this study was to shed light on the relationship between the condition of paraspinal muscles and symptomatic DLSS.

Methods

Two sample populations were studied. The first included 165 individuals with DLSS (age range: 40–88, sex ratio: 80 M/85 F) and the second 180 individuals without spinal stenosis related symptoms and low back pain (age range: 40–99, sex ratio: 90 M/90 F). Measurements were taken at the middle part of L3 vertebral body, using CT axial images (Philips Brilliance 64). Muscles density was measured in Hounsfield units (HU) using a 50 mm² circle of the muscle mass at three different locations and the mean density was then calculated. The cross-sectional area (CSA) was also measured using the quantitative CT angiography method. Analysis of Covariance (adjusted for body mass index and age) was performed in order to determine the relationship between the condition of paraspinal muscles and symptomatic DLSS.

Results

Individuals in the stenosis group had higher muscle density as compared to the control group. The CSA values for the erector spinae (both sexes) and psoas (males) muscles were significantly greater in the stenosis group as compared to their counterparts in the control group. Additionally, density of multifidus (both sexes) and erector spinae (males) muscles was significantly associated with symptomatic DLSS.

Conclusions

Our results show that individuals with symptomatic DLSS manifest greater paraspinal muscles density and CSA (erector spinae), compared to the control group. Density of multifidus increases the likelihood of symptomatic DLSS.

Effects of a 16-week Pilates exercises training program for isometric trunk extension and flexion strength

OBJECTIVE

To evaluate the effects of Pilates exercises designed to improve isometric trunk extension and flexion strength of muscles in women with chronic low back pain (cLBP).

PARTICIPANTS

Female volunteers with cLBP were divided into an experimental group (EG; n = 27) and a control group (CG; n = 27).

INTERVENTION

Pilates exercises were performed twice per week by the EG; the duration of each session was 60 min. The program lasted for 16 weeks; thus patients underwent a total of 32 exercise sessions.

RESULTS

The maximum isometric waist bending strength of the EG had improved significantly (p = 0.001) after 16 weeks of the Pilates program. The results of trunk flexion muscle endurance tests significantly depended on the trunk extension muscle endurance before the intervention, and at 1 month (r = 0.723, p < 0.001) and 2 months (r = 0.779, p < 0.001) after the Pilates exercise program. At the end of the 16-week exercise program, cLBP intensity decreased by 2.01 ± 0.8 (p < 0.05) in the EG, and this reduction persisted for 1 month after completion of the program.

CONCLUSIONS

At 1 and 2 months after cessation of the Pilates exercise program the pain intensified and the functional state deteriorated much faster than the maximum trunk muscle strength. Therefore, it can be concluded that, to decrease pain and improve functional condition, regular exercise (and not only improved strength and endurance) is required. We established that, although the 16-week lumbar stabilization exercise program increased isometric trunk extension and flexion strength and this increase in strength persisted for 2 months, decreased LBP and improved functional condition endured for only 1 month.

Isokinetic performance, functionality, and pain level before and after lumbar and pelvic estabilization exercise in individuals with chronic low back pain

Introduction Chronic low back pain with a mechanical and degenerative origin is among the most common symptoms experienced by people all over the world. Objective To analyze the effects of a protocol for lumbar and pelvic segmental stabilization with regard to isokinetic variables, functionality, and pain in patients with low back pain. Materials and methods The sample consisted of 21 subjects, 8 female and 13 male, with a mean age of 42.6 ± 12.5 years. We used tests for mobility (modified Schober index), flexibility (finger-floor distance), functionality (Roland-Morris questionnaire), pain (Visual Analog Scale of Pain), and the isokinetic variables torque peak, work, flexors/extensors ratio before and after application of a protocol for segmental stabilization in subjects with chronic low back pain with a mechanical and degenerative origin. This protocol was used for two months, being applied twice a week. The data were statistically tested by means of the software Statistica, version 8.0. Results There were significant improvements for the variables flexibility (p = 0.014), functionality (p < 0.001), pain level (p < 0.001), torque peak flexion (p = 0.008), torque peak range (p < 0.001), torque flexion (p = 0.001), torque range (p < 0.001), and flexors/extensors ratio (p = 0.001). Conclusion Even with the improved levels of trunk muscles strength, both flexors and extensors, it was not possible to rebalance the segment according to data available in the literature. It is believed that there is a need for a protocol with a longer application period, maintaining the recruitment of extensor muscles. Regarding mobility of the lumbar segment, the protocol showed no significant differences in post-treatment (p = 0.520). This may be attributed to improved muscle control, providing the increased passive stiffness required to promote stability.

Psychometric properties of the pain stages of change questionnaire as evaluated by Rasch analysis in patients with chronic musculoskeletal pain

Background

Our objective was to evaluate the measurement properties of the Pain Stages of Change Questionnaire (PSOCQ) and its four subscales Precontemplation, Contemplation, Action and Maintenance.

Methods

A total of 231 patients, median age 42 years, with chronic musculoskeletal pain responded to the 30 items in PSOCQ. Thresholds for item scores, and unidimensionality and invariance of the PSOCQ and its four subscales were evaluated by Rasch analysis, partial credit model.

Results

The items had disordered threshold and needed to be rescored. The 30 items in the PSOCQ did not fit the Rasch model Chi- square item trait statistics. All subscales fitted the Rasch models. The associations to pain (11 point numeric rating scale), emotional distress (Hopkins symptom check list v 25) and self-efficacy (Arthritis Self-Efficacy Scale) were highest for the Precontemplation subscale.

Conclusion

The present analysis revealed that all four subscales in PSOCQ fitted the Rasch model. No common construct for all subscales were identified, but the Action and Maintenance subscales were closely related.

Isokinetic trunk muscle performance in pre-teens and teens with and without back pain

OBJECTIVE

To assess with an isokinetic dynamometer the force and endurance of the spinal flexor and extensor muscles in pre-teens or teens aged 11 to 13 and 14 to 16 years with and without low back pain (LBP).

METHOD

The control group and the LBP group were homogeneous in terms of age, weight, height and Body Mass Index (BMI). Assessment was carried out with the isokinetic dynamometer Cybex Norm®. The spinal flexors and extensors were explored concentrically at speeds of 60°, 90° and 120°/sec. The parameters chosen were: maximal moment of force (MMF), mean power (MP), total work (TW), F/E ratios (between the flexors and the extensors for the aforesaid parameters). In the LBP groups, clinical information (pain, extensibility of the spinal and sub-pelvic muscles, sports practice) and sagittal radiological data were all measured.

RESULTS

While no significant difference in isokinetic performance was found between asymptomatic and LBP children in the 11-to-13-year-old group, the isokinetic performances of the LBP children were influenced positively by BMI value, number of hours of physical activity and radiologic value of the lumbar lordosis. As regards these pre-teens, assessment with an isokinetic dynamometer does not highlight muscle characteristics that might explain LBP occurrence. As regards the 14-to-16-year-old group, muscle strength has been found to be correlated with age. LBP teens were showed to have weaker extensors and stronger flexors than the healthy teens. It is with regard to this age group that assessment with an isokinetic dynamometer clearly yields interesting results. Since we have yet to standardize our evaluation criteria (working speed, number of trials…), it is difficult to compare our results with those reported in the literature.

CONCLUSION

This is a preliminary study involving a relatively low number of patients. That said, given the fact that numerous parameters are connected with the age and height of the subjects, assessment with an isokinetic dynamometer can be constructively carried out from the age of 14. In order to further enhance understanding of this phenomenon, a longitudinal and comparative study of a larger group is needed.

Decline in lumbar extensor muscle strength the older adults: correlation with age, gender and spine morphology

BACKGROUND

Muscle morphology, age and gender may be determinants of muscle strength in older adults. However, very few research studies have directly examined such correlation in the ageing spine. The aim of the study was to examine the correlation between lumbar extensor muscle strength, its muscle fibre angles, thoracolumbar curvature, age and gender in the older and younger adults.

METHODS

Muscle fibre angles of lumbar extensor muscles, thoracolumbar curvature and lumbar extensor muscle strength were examined in 26 young (mean age 27.9, SD 5.2) and 26 older (mean age 72.1, SD 5.9) participants. Pearson's correlation was employed to determine the association among lumbar extensor muscle fibre angle, thoracolumbar curvature, age, gender and lumbar extensor muscle strength. Multiple stepwise linear regression analysis was used to identify significant determinants of lumbar extensor muscle strength.

RESULTS

The results demonstrated a significant correlation between lumbar extensor muscle strength, muscle fibre angle, age and gender. In the step wise regression analysis, both gender and age were identified as the most robust determinant for lumbar extensor muscle strength in older adults. However, gender was the only determinant of muscle strength in the young.

CONCLUSION

These results suggest that the decline in the lumbar extensor muscle strength in older adults was more dependent on age when compared to younger adults.

The Relationship between Cross Sectional Area and Strength of Back Muscles in Patients with Chronic Low Back Pain

Objective

To evaluate the relationship between the cross sectional area (CSA) and isokinetic strength of the back muscles in patients with chronic low back pain.

Method

Data of twenty-eight middle-aged patients with chronic back pain were analyzed retrospectively. CSAs of both paraspinal muscles and the disc at the L4-L5 level were measured in MRI axial images and the relative CSAs (rCSA: CSA ratio of muscle and disc) were calculated. The degree of paraspinal muscle atrophy was rated qualitatively. Isokinetic strengths (peak torque, peak torque per body weight) of back flexor and extensor were measured with the isokinetic testing machine. Multiple regression analysis with backward elimination was used to evaluate relations between isokinetic strength and various factors, such as CSA or rCSA and clinical characteristics in all patients. The same analysis was repeated in the female patients.

Results

In analysis with CSA and clinical characteristics, body mass index (BMI) and CSA were significant influencing factors in the peak torque of the back flexor muscles. CSA was a significant influencing factor in the peak torque of total back muscles. In analysis with rCSA and clinical characteristics, BMI was significant in influencing the peak torque of the back flexors. In female patients, rCSA was a significant influencing factor in the peak torque per body weight of the back flexors, and age and BMI were influencing factors in the peak torque of back flexors and total back muscles.

Conclusion

In middle-aged patients with chronic low back pain, CSA and rCSA were influencing factors in the strength of total back muscles and back flexors. Also, gender and BMI were influencing factors.

Evidence for a direct relationship between cognitive and physical change during an education intervention in people with chronic low back pain

BACKGROUND

Unhelpful pain cognitions of patients with chronic low back pain (LBP) may limit physical performance and undermine physical assessment. It is not known whether a direct relationship exists between pain cognitions and physical performance.

AIMS

To determine if a relationship exists between change in pain cognitions and change in physical performance when chronic LBP patients participate in a single one-to-one education intervention during which they have no opportunity to be active.

METHODS

In a quasi-experiment using a convenience sample, moderately disabled chronic LBP patients (n=121) participated in a one-to-one education session about either lumbar spine physiology or pain physiology. Multiple regression analysis evaluated the relationship between change in pain cognitions measured by the survey of pain attitudes (SOPA) and the pain catastrophising scale (PCS) and change in physical performance, measured by the straight leg raise (SLR) and standing forward bending range.

RESULTS

There was a strong relationship between cognitive change and change in straight leg raise (SLR) and forward bending (r=0.88 and 0.79, respectively, P<0.01), mostly explained by change in the conviction that pain means tissue damage and catastrophising.

CONCLUSIONS

Change in pain cognitions is associated with change in physical performance, even when there is no opportunity to be physically active. Unhelpful pain cognitions should be considered when interpreting physical assessments.

No difference in long-term trunk muscle strength, cross-sectional area, and density in patients with chronic low back pain 7 to 11 years after lumbar fusion versus cognitive intervention and exercises

BACKGROUND CONTEXT

Reduced muscle strength and density observed at 1 year after lumbar fusion may deteriorate more in the long term.

PURPOSE

To compare the long-term effect of lumbar fusion and cognitive intervention and exercises on muscle strength, cross-sectional area, density, and self-rated function in patients with chronic low back pain (CLBP) and disc degeneration.

STUDY DESIGN

Randomized controlled study with a follow-up examination at 8.5 years (range, 7-11 years).

PATIENTS AND METHODS

Patients with CLBP and disc degeneration randomized to either instrumented posterolateral fusion of one or both of the two lower lumbar levels or a 3-week cognitive intervention and exercise program were included. Isokinetic muscle strength was measured by a Cybex 6000 (Cybex-Lumex, Inc., Ronkonkoma, NY, USA). All patients had previous experience with the test procedure. The back extension (E) flexion (F) muscles were tested, and the E/F ratios were calculated. Cross-sectional area and density of the back muscles were measured at the L3-L4 segment by computed tomography. Patients rated their function by the General Function Score.

OUTCOME MEASURES

Trunk muscle strength, cross-sectional area, density, and self-rated function.

RESULTS

Fifty-five patients (90%) were included at long-term follow-up. There were no significant differences in cross-sectional area, density, muscle strength, or self-rated function between the two groups. The cognitive intervention and exercise group increased trunk muscle extension significantly (p<.05), and both groups performed significantly better on trunk muscle flexion tests (p<.01) at long-term follow-up. On average, self-rated function improved by 56%, cross-sectional area was reduced by 8.5%, and muscle density was reduced by 27%.

CONCLUSION

Although this study did not assess the morphology of muscles likely damaged by surgery, trunk muscle strength and cross-sectional area above the surgical levels are not different between those who had lumbar fusion or cognitive intervention and exercises at 7- to 11-year follow-up.

The association of nutritional status and gender with cross-sectional area of the multifidus muscle in establishing normative data

Despite recognized evidence for the importance of the multifidus muscle in stabilizing the lumbar spine, identifying subjects at risk for injury and subsequent loss of intrinsic spinal stabilization remains difficult. Previous research has failed to associate multifidus muscle size and height, weight, or body mass index (BMI). The purpose of this study was to begin to establish normative data for the multifidus muscle cross-sectional area (CSA) at the L5 level and to identify factors associated with size. Twenty-five participants (17 female), with a mean age of 32.5 (SD 11.6) years without history of LBP were considered for inclusion. Participants' height and weight were recorded and BMI calculated. Ultrasound imaging was used to obtain a CSA in cm(2) of the subjects' multifidus muscles at the L5 level bilaterally; testing was done by two trained testers. Prior to testing, intra- and inter-tester reliability were determined. Percent body fat was determined using a three-site skinfold caliper measurement, also using two trained testers. Mean BMI was 24.18 and mean body fat (%) was 22.88 for all participants. As expected, age and BMI were moderately correlated. Left and right multifidus muscle CSA were highly correlated (r = 0.92, p < 0.001). The mixed model ANOVA indicated a significant main effect for gender as males exhibited larger CSA than females. Participants without history of low back pain present with symmetrical multifidus muscle CSA at the L5 level. Clear gender differences in CSA show that males tend to have larger multifidus muscles at the L5 level, indicating a need to establish gender-specific norms for clinicians examining the L5 multifidus muscle.

Reliability of magnetic resonance imaging measurements of the cross-sectional area of the muscle contractile and non-contractile components

BACKGROUND/PURPOSE

Magnetic resonance imaging (MRI) is increasingly used to study skeletal muscles patients with muscular disorders. We report an MRI technique for evaluating the trunk muscles. This technique takes both the component surface area (CSA) and the density of the muscles on MRI axial slices into account . Using a computer-based image analysis system, we combined MRI data measuring the muscle CSA, which was separated into the contractile component (CCSA) and the non-contractile component (NCCSA). The purpose of this study was to analyze the reliability of this method of measuring the CSA, CCSA and NCCSA in trunk muscles on MRI axial slices through L4 and T12.

METHODS

Thirty volunteer subjects were enrolled in this study. Two acquisitions were performed. For the reliability analyses, each of the two slices (T12 and L4) from 30 subjects was measured by three raters trained in this technique, on two occasions 2 weeks apart. Each muscle was surrounded and its CSA, NCCSA and CCSA were recorded. For each muscle, the agreement between the two sets of 30 measurements performed by three observers was evaluated by calculating an intra-class correlation coefficient (ICC).

RESULTS

Regarding the slice through L4 and T12, the reliabilities of the measurement of CSA, CCSA were very good for all the muscles except the parietal muscles.

CONCLUSION

MRI measurements of the trunk muscle cross-sectional areas and of the CCSA and NCCSA are reliable.

Changes in paraspinal muscles and their association with low back pain and spinal degeneration: CT study

The objectives of the study were to evaluate the association between lumbar paraspinal muscle density, evaluated on computed tomography (CT) and age, sex and BMI; and to evaluate the association of those changes with low back pain (LBP) and spinal degeneration features in a community-based sample. This study was an ancillary project to the Framingham Study. A sample of 3,529 participants aged 40-80 years had a CT scan performed to assess aortic calcification. 187 individuals were randomly enrolled in this study. LBP in the last 12 months was evaluated using self-report questionnaire. Density (in Hounsfield units) of multifidus and erector spinae was evaluated on CT. The prevalence of intervertebral disc narrowing, facet joint osteoarthritis (FJOA), spondylolysis, spondylolisthesis and spinal stenosis were also evaluated. We used linear regression models to examine the association of paraspinal muscles density with age, sex, BMI, LBP, and spinal degeneration features. The results show that in our study, men have higher density of paraspinal muscles than women, younger individuals have higher density than older ones and individuals with lower weight have higher muscle density than overweight. No differences between individuals with and without LBP were found. Significant association was found between L4 multifidus/erector spinae density and FJOA at L4-L5; between multifidus at L4 and spondylolisthesis at L4-5; and between erector spinae at L4 and L5 with disc narrowing at L4-5 and L5-S1, respectively. We conclude that the paraspinal muscle density decreases with age, and increases BMI. It is associated with at some levels FJOA, spondylolisthesis and disc narrowing at the same level, but not associated with occurrence of LBP.

The association of physical deconditioning and chronic low back pain: A hypothesis-oriented systematic review

PURPOSE

Does physical deconditioning (loss of cardiovascular capacity and strength/endurance of paraspinal muscles) exist in patients with chronic low back pain (CLBP) and are treatments specifically aimed to reduce these signs effective?

METHOD

Systematic literature search in PUBMED, MEDLINE, EMBASE and PsycINFO until December 2004 to identify observational studies regarding deconditioning signs and high quality RCTs regarding the effectiveness of cardiovascular and/or muscle strengthening exercises. Internal validity of the RCTs was assessed by using a checklist of nine methodology criteria in accordance with the Cochrane Collaboration.

RESULTS

There is conflicting evidence that cardiovascular deconditioning is present in CLBP and limited evidence for wasting of the multifidus muscle. No study examined the effectiveness of cardiovascular training specifically. General and lumbar muscle strengthening are equally effective as other active treatments. Only moderate evidence is available for the effectiveness of intensive low back extensor muscle strengthening compared to less intensive strengthening.

CONCLUSION

Probably reactivation caused by active treatment and not the reconditioning itself is the important factor in the reduction of disability. Further prospective and evaluative research into the role of physical deconditioning is necessary. It seems more promising to further explore the interplay between biological, social and psychological factors.

Comparison of isokinetic exercise versus standard exercise training in patients with chronic low back pain: a randomized controlled study

OBJECTIVE

To compare the effectiveness of an isokinetic exercise programme and a standard exercise programme in patients with chronic low back pain in terms of pain, mobility, disability, psychological status and muscle strength.

DESIGN

A randomized controlled trial.

SETTING

An outpatient rehabilitation clinic.

SUBJECTS

A total of 40 patients with low back pain were included in the study.

INTERVENTIONS

Patients with low back pain were randomly allocated into group 1 (n=20, isokinetic exercises) and group 2 (n=20, standard exercise).

MAIN MEASURES

Outcome measures included a visual analogue scale (VAS) for pain, fingertip-to-floor test for spinal mobility, Modified Oswestry Low Back Disability Questionnaire (MOLBDQ), Beck Depression Inventory and isokinetic muscle testing.

RESULTS

The isokinetic and standard exercise groups demonstrated significant improvement in the VAS, fingertip-to-floor test, MOLBDQ, Beck Depression Inventory scores, and muscle strength compared with the baseline that persisted until the end of the first month (P<0.05). Comparison of both exercise groups in terms of these parameters obtained at the end of the treatment and at the first month after treatment showed no significant difference (P>0.05).

CONCLUSION

Isokinetic and standard exercise programmes have an equal effect in the treatment of low back pain, with no statistically significant difference found between the two programmes. The standard exercise programme was easily performed and had a low cost, making it the preferred option for exercise.

Systematic review of back schools, brief education, and fear-avoidance training for chronic low back pain

BACKGROUND

Seven previous systematic reviews (SRs) have evaluated back schools, and one has evaluated brief education, with the latest SR including studies until November 2004. The effectiveness of fear-avoidance training has not been assessed.

PURPOSE

To assess the effectiveness of back schools, brief education, and fear-avoidance training for chronic low back pain (CLBP).

STUDY DESIGN

A SR.

METHODS

We searched the MEDLINE database of randomized controlled trials (RCT) until August 2006 for relevant trials reported in English. Assessment of effectiveness was based on pain, disability, and sick leave. RCTs that reported back schools, or brief education as the main intervention, were included. For fear-avoidance training, evaluation of domain-specific outcome was required. Two reviewers independently reviewed the studies.

RESULTS

Eight RCTs including 1,002 patients evaluated back schools, three studies were of high quality. We found conflicting evidence for back schools compared with waiting list, placebo, usual care, and exercises, and a cognitive behavioral back school. Twelve trials including 3,583 patients evaluated brief education. Seven trials, six of high quality, evaluated brief education in the clinical setting. We found strong evidence of effectiveness on sick leave and short-term disability compared with usual care. We found conflicting or limited evidence for back book or Internet discussion (five trials, two of high quality) compared with waiting list, no intervention, massage, yoga, or exercises. Three RCTs of high quality, including 364 patients, evaluated fear-avoidance training. We found moderate evidence that there is no difference between rehabilitation including fear-avoidance training and spinal fusion.

CONCLUSIONS

Consistent recommendations are given for brief education in the clinical setting, and fear-avoidance training should be considered as an alternative to spinal fusion, and back schools may be considered in the occupational setting. The discordance between reviews can be attributed differences in inclusion criteria and application of evidence rules.

The reliability of paraspinal muscles composition measurements using routine spine MRI and their association with back function

This study examines the reliability of quantitative and qualitative muscle composition measurements of paraspinal muscle cross-sectional areas (CSAs) from routine lumbar spine magnetic resonance images and their association with maximal isokinetic lifting performance. The extent of paraspinal muscle composition reflects back function is currently not known. Measurements were repeated 4-8 weeks apart and different measurements of related constructs were compared. Participants were a population-based sample of 169 males, 35-67 years old, without considering the presence or absence of a history of low back pain or related problems in the selection of subjects. The quantitative and qualitative muscle composition measurements for axial magnetic resonance (MR) images of paraspinal muscles at the L3-L4 lumbar spine level, isokinetic lifting force and work, and body fat percentage were the main outcome measures. Results showed that the reproducibility of different paraspinal muscle composition measurements at the L3-L4 level was excellent for CSAs (ICC=0.95-0.99) and quantitative muscle composition measurements using cerebrospinal fluid adjusted signal intensity (ICC=0.96-0.99), and moderate for qualitative muscle composition ratings (Kappa=0.54-0.76). The correlations of the quantitative and qualitative muscle composition measurements with isokinetic lifting force and work were generally low (r=0.02-0.41), and favoured the qualitative assessments. In conclusion, quantitative and qualitative muscle composition measurements of paraspinal muscles are highly reproducible tissue measures, have low associations with body fat and isokinetic lifting performance, and show that paraspinal muscle morphology using routine spine magnetic resonance imaging (MRI) is poorly related to back function.

Evidence-informed management of chronic low back pain with back schools, brief education, and fear-avoidance training

The management of chronic low back pain (CLBP) has proven very challenging in North America, as evidenced by its mounting socioeconomic burden. Choosing among available nonsurgical therapies can be overwhelming for many stakeholders, including patients, health providers, policy makers, and third-party payers. Although all parties share a common goal and wish to use limited health-care resources to support interventions most likely to result in clinically meaningful improvements, there is often uncertainty about the most appropriate intervention for a particular patient. To help understand and evaluate the various commonly used nonsurgical approaches to CLBP, the North American Spine Society has sponsored this special focus issue of The Spine Journal, titled Evidence-Informed Management of Chronic Low Back Pain Without Surgery. Articles in this special focus issue were contributed by leading spine practitioners and researchers, who were invited to summarize the best available evidence for a particular intervention and encouraged to make this information accessible to nonexperts. Each of the articles contains five sections (description, theory, evidence of efficacy, harms, and summary) with common subheadings to facilitate comparison across the 24 different interventions profiled in this special focus issue, blending narrative and systematic review methodology as deemed appropriate by the authors. It is hoped that articles in this special focus issue will be informative and aid in decision making for the many stakeholders evaluating nonsurgical interventions for CLBP.

Rehabilitative ultrasound imaging of the abdominal muscles

Rehabilitative ultrasound imaging (RUSI) of the abdominal muscles is increasingly being used in the management of conditions involving musculoskeletal dysfunctions associated with the abdominal muscles, including certain types of low back and pelvic pain. This commentary provides an overview of current concepts and evidence related to RUSI of the abdominal musculature, including issues addressing the potential role of ultrasound imaging in the assessment and training of these muscles. Both quantitative and qualitative aspects associated with clinical and research applications are considered, as are the possible limitations related to the interpretation of measurements made with RUSI. Research to date has utilized a range of methodological approaches, including different transducer placements and imaging techniques. The pros and cons of the various methods are discussed, and guidelines for future investigations are presented. Potential implications and opportunities for clinical use of RUSI to enhance evidence-based practice are outlined, as are suggestions for future research to further clarify the possible role of RUSI in the evaluation and treatment of abdominal muscular morphology and function.

Spinal muscle evaluation in healthy individuals and low-back-pain patients: a literature review

This article reviews available techniques for spinal muscle investigation, as well as data on spinal muscles in healthy individuals and in patients with low back pain. In patients with chronic low back pain, medical imaging studies show paraspinal muscle wasting with reductions in cross-sectional surface area and fiber density. In healthy individuals, the paraspinal muscles contain a high proportion of slow-twitch fibers (Type I), reflecting their role in maintaining posture. The proportion of Type I fibers is higher in females, leading to better adaptation to aerobic exertion compared to males. Abnormalities seen in paraspinal muscles from patients with chronic low back pain include marked Type II fiber atrophy, conversion of Type I to Type II fibers, and an increased number of nonspecific abnormalities. Limited data are available from magnetic resonance spectroscopy used to investigate muscle metabolism and from near infrared spectroscopy used to measure oxygen uptake by the paraspinal muscles. Surface electromyography in patients with chronic low back pain shows increased paraspinal muscle fatigability, often with abolition of the flexion-relaxation phenomenon.

Relationships among lateral abdominal muscles, gender, body mass index, and hand dominance

STUDY DESIGN

Exploratory.

OBJECTIVES

To explore whether hand dominance, gender, and body mass index (BMI) influence the thickness of the lateral abdominal muscles as measured by ultrasound imaging. To document the extent of improvement in response stability when an average of multiple measures was utilized.

BACKGROUND

Ultrasound imaging is a relatively new tool used to assess the lateral abdominal muscles. A better understanding of how these muscles contract in a healthy population can provide a reference for comparison to patients with low back pain (LBP).

METHODS AND MEASURES

Thirty-two healthy participants (17 males, 15 females) aged 18 to 45 years (mean +/- SD, 31.9 +/- 7.8 years) were studied. Measurements of muscular thickness of the lateral abdominal muscles were obtained bilaterally while the subjects were at rest, and while they performed the abdominal drawing-in maneuver. To determine the possible influence of hand dominance and gender on muscle thickness, t tests were used. Correlation coefficients were used to assess the relationship between BMI and muscle thickness. Standard error of the measurement was used to assess response stability of the ultrasound imaging technique.

RESULTS

No differences in the thicknesses of the transversus abdominis (TrA) muscle were measured during rest or while contracted, based on hand dominance (P > or = .73). Men had greater muscular thickness (P<.01), while the TrA in women represented a greater proportion of the total lateral abdominal muscles (P<.01). BMI was positively associated with muscle thickness (r> or =.66). Compared to a singular measurement, response stability improved by greater than 50% when an average of 3 measurements was used.

CONCLUSIONS

Future researchers should assess the need to control for gender and BMI as potential covariates in ultrasound imaging studies of the lateral abdominal muscles. Asymmetry in the lateral abdominal muscles in those with LBP would be in direct contrast to the bilateral symmetry measured in those without LBP.

Prediction of back strength using anthropometric and strength measurements in healthy females

OBJECTIVES

The purpose of this study was to develop a regression equation to predict back extensor maximal voluntary contraction (back strength) for females based on several anthropometric and strength measurements using a multiple regression technique.

BACKGROUND

Back strength is an important parameter in low back pain studies. However, the measurement of back strength is problematic in certain populations such as low back pain patients and pregnant women.

METHODS

Back strength was measured as both moment at L4/L5 and force. Ten anthropometric or strength measurements were chosen to develop the prediction equation. The data used for developing the models were from eighty non-pregnant female subjects, age 18-42 and with no history of back pain in the past year. Backwards stepwise analysis was performed in order to choose the best fit predictors. The predictive ability of each of the models was checked using the cross-validation technique on 20 other subjects.

FINDINGS

Two prediction models were developed for moment and force, respectively. The models explained 46.9% and 48.2% of the variance in back strength. No multicollinearity problem was found. The validation study showed that the observed back strength was highly correlated with the predicted back strength.

INTERPRETATION

Mass, height, trunk length, grip strength and quadriceps strength are the best predictors of back strength in this study. The models developed in this study can be used for both general female low back pain patients and the pregnancy population.

Minimum 20-year follow-up results of Harrington rod fusion for idiopathic scoliosis

We evaluated the outcome of spinal fusion with a single Harrington distraction rod in patients with idiopathic scoliosis. At follow-up visits a minimum of 20 years post-surgery, we studied 24 patients who had been operated on by the same surgeon. The Scoliosis Research Society (SRS) Instrument and an additional questionnaire of our own, along with an invitation for a follow-up visit, were originally mailed to 28 consecutive patients of the surgeon. The SRS Instrument has seven domains dealing with back pain, general self-image, self-image after surgery, general function, function in terms of level of activity, function after surgery, and degree of satisfaction with the surgery. The length of time between surgery and the follow-up visit averaged 22.9 years (20.2-27.3). The mean age at surgery and follow-up were 15.8 (13-22) and 38.8 (35-48) years, respectively. Twenty-four patients sent back the completed questionnaires and 16 of them participated in the clinic and radiographic follow-up. To assess the meaning of the questionnaires' results, a control group of the same sex, age and geographic provenance was selected from our outpatients without scoliosis. The average follow-up score on the SRS Instrument for the patients was 100.8 (78-110). When we compared the study and control groups, no significant differences in the single SRS domain scores were observed. The mean Cobb angle and rib cage deformity before surgery were 70.46 degrees (40-120) and 36.4 mm (20-60 mm), respectively, whereas on follow-up they were 41.23 degrees (16-75) and 22.3 mm (5-50 mm), respectively. These long-term results lead us to consider Harrington fusion a procedure that produces a long-lasting high degree of self-reported post-operative satisfaction.

Surface electromyography of the paravertebral muscles in patients with chronic low back pain

OBJECTIVE

To investigate the differences in the electromyographic signals of patients with chronic low back pain (CLBP) and healthy subjects.

DESIGN

Cross-sectional study with a matched-pair design.

SETTING

University hospital.

PARTICIPANTS

Thirty-one patients with CLBP and 31 healthy, matched-pair controls.

INTERVENTIONS

The mean rectified surface electromyographic amplitude and muscle strength were measured during maximal voluntary contraction (MVC). During an endurance test at 60% of MVC, the electromyographic parameters of the 2 groups were compared.Main outcome measure Electromyographic measuring of local fatigue, which can be described with changes in the median frequency or by a different parameter of the power spectrum called frequency banding.

RESULTS

The strength measurement revealed a deficiency of 40% in the patients and a deficit in the electromyographic amplitude of approximately 60%, compared with the control group. By pairwise comparison, the decrease in the median frequency during the endurance test was greater in the control group. In the frequency banding of the power spectrum, local fatigue was less pronounced in the CLBP patients in pairwise comparison.

CONCLUSIONS

The back muscles of CLBP patients appear to be less fatigable than those of controls. The results can be explained by morphologic changes, but influences such as pain, avoidance of pain, and deconditioning, need to be considered when the results are assessed.

Étude comparative entre technique isocinétique et kinésithérapie classique chez le lombalgique chronique. Résultats préliminaires

OBJECTIVE

To determine if the use of an isokinetic device for trunk exercise is more effective than standard physiotherapy in promoting motor disinhibition for patients with chronic low back pain.

POPULATION

chronic low back pain outpatients who are treated in a Rheumatology or PM & R unit within an academic hospital.

METHODOLOGY

This is a prospective, controlled, randomized study, with two groups of treatment: one treated with isokinetic techniques and the other with standard physiotherapy, six sessions for each treatment during 2 weeks. Outcome measures include pain (VSA), trunk mobility (Schöber index, distance from fingers to floor), muscle extensibility and muscle strength (Biering-Sorensen and Shirado-Ito test), and functional capacity (Quebec scale).

RESULTS

Seventeen subjects were enrolled. The results suggest that both isokinetic exercise and physiotherapy result in improved range of motion, extensibility, muscle strength, and pain, without any significant superiority of one technique over the other. However, each technique has specific advantage.

DISCUSSION

Despite methodologic limitations, this study shows that isokinetic exercise is not better than physiotherapy in reversing motor inhibition in chronic low back pain. Our results are consistent with those of other studies in the literature, with regard to the absence of established overall superiority of one exercise technique or program over the other in this population, and with regard to partial benefits of specific exercise techniques.

CONCLUSION

The non-specific benefit of one technique indicates that further studies are needed to evaluate the benefit of combining exercise techniques in chronic low back pain, in order to address the multiple factors involved in this pathology.

Back strength cannot be predicted accurately from anthropometric measures in subjects with and without chronic low back pain

OBJECTIVES

(1) To develop a multiple regression equation using anthropometric measurements to predict back strength and (2) to estimate the effect of practice on the back strength results and back strength predictions.

DESIGN

Comparative study with repeated measures performed on three days.

BACKGROUND

The assessment of back muscle relative endurance (% maximal strength) requires the measurement of maximal back strength which is problematic with low back pain patients.

METHODS

The back strength (L5/S1 static extension moment), age and 26 anthropometric parameters were obtained from 83 male volunteers [42 healthy subjects and 41 chronic low back pain patients] aged between 20 and 60 years. A subsample of 20 healthy subjects and 20 patients were assessed through three days of testing to evaluate the variations of back strength with practice.

RESULTS

The final regression model (n=42 healthy subjects) explained 39% of the variance in back strength. Back strength increased with practice (Day1<Day2 & 3) for both healthy and patients groups. However, the error of prediction of back strength derived from the regression model showed a significant improvement with practice for the patients only.

CONCLUSIONS

Back strength cannot be predicted from simple anthropometric measures without important errors. The decrease of the error of prediction obtained for the patient group is indicative of a decreasing influence of psychological factors that are independent of motor learning because the effect of motor learning would have occurred on both groups if present.

RELEVANCE

The prediction of back strength would be useful to determine (1) the relative force level of a given exercise or (2) the preinjury back strength. Unfortunately, anthropometric measurements are not enough good predictors of back strength.