Muscle Atrophy Measurement as Assessment Method for Low Back Pain Patients

Comparison of concentric and eccentric resistance training in terms of changes in the muscle contractile properties

The habitual use of resistance exercises involving concentric and eccentric contractions can increase muscle strength, speed and endurance. However, current knowledge has limited potential to fully understand the application of such resistance training and the muscle changes that occur to differentiate these two types of training. The aim of this study was to compare the effects of concentric contraction (CON) and eccentric contraction (ECC) during an acute bout of resistance training on the hamstring contractile properties. A group of 20 female recreational athletes were divided into two equal groups, CON training and ECC training. The contractile properties of the muscles on both sides of the body were assessed using tensiomyography (TMG): biceps femoris (BF) and semitendinosus (ST). The muscles were assessed twice, before and after 10 maximal repetitions of either concentric or eccentric isotonic contractions. The results indicate a greater change in TMG parameters with ECC training, with p < 0.001 (Td and Tc). An acute bout of resistance training induces changes in the muscle hamstrings contractile properties in both CON and ECC training. Eccentric training causes greater changes than concentric training, shortening contraction time (Td, Tc), increase radial displacement velocity (Vrd) and affecting changes in muscle belly displacement (Dm), so may be more effective in training.

Bioinformatics analysis of paravertebral muscles atrophy in adult degenerative scoliosis

Paravertebral muscles (PVM) act as one of the major dynamic factors to maintain human upright activities and play a remarkable role in maintaining the balance of the trunk. Adult degenerative scoliosis (ADS) has become one of the important causes of disability in the elderly population owing to the changes in spinal biomechanics, atrophy and degeneration of PVM, and imbalance of the spine. Previously, many studies focused on the physical evaluation of PVM degeneration. However, the molecular biological changes are still not completely known. In this study, we established a rat model of scoliosis and performed the proteomic analysis of the PVM of ADS. The results showed that the degree of atrophy, muscle fat deposition, and fibrosis of the PVM of rats positively correlated with the angle of scoliosis. The proteomic results showed that 177 differentially expressed proteins were present in the ADS group, which included 105 upregulated proteins and 72 downregulated proteins compared with the PVM in individuals without spinal deformities. Through the construction of a protein-protein interaction network, 18 core differentially expressed proteins were obtained, which included fibrinogen beta chain, apolipoprotein E, fibrinogen gamma chain, thrombospondin-1, integrin alpha-6, fibronectin-1, platelet factor 4, coagulation factor XIII A chain, ras-related protein Rap-1b, platelet endothelial cell adhesion molecule 1, complement C1q subcomponent subunit A, cathepsin G, myeloperoxidase, von Willebrand factor, integrin beta-1, integrin alpha-1, leukocyte surface antigen CD47, and complement C1q subcomponent subunit B. Further analysis of the Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) and immunofluorescence showed that the neutrophil extracellular traps (NETs) formation signaling pathway plays a major role in the pathogenesis of PVM degeneration in ADS. The results of the present study preliminarily laid the molecular biological foundation of PVM atrophy in ADS, which will provide a new therapeutic target for alleviating PVM atrophy and decreasing the occurrence of scoliosis.

Machine Learning Prediction Model and Risk Factor Analysis of Reoperation in Recurrent Lumbar Disc Herniation Patients After Percutaneous Endoscopic Lumbar Discectomy

OBJECTIVE

To investigate the risk factors of reoperation after percutaneous endoscopic lumbar discectomy (PELD) due to recurrent lumbar disc herniation (rLDH) and to establish a set of individualized prediction models.

METHODS

Patients who underwent PELD successfully from January 2016 to February 2022 in a single institution were enrolled in this study. Six methods of machine learning (ML) were used to establish an individualized prediction model for reoperation in rLDH patients after PELD, and these models were compared with logistics regression model to select optimal model.

RESULTS

A total of 2603 patients were enrolled in this study. 57 patients had repeated operation due to rLDH and 114 patients were selected from the remaining 2546 nonrecurrent patients as matched controls. Multivariate logistic regression analysis showed that disc herniation type (P < .001), Modic changes (type II) (P = .003), sagittal range of motion (sROM) (P = .022), facet orientation (FO) (P = .028) and fat infiltration (FI) (P = .001) were independent risk factors for reoperation in rLDH patients after PELD. The XGBoost AUC was of 90.71%, accuracy was approximately 88.87%, sensitivity was 70.81%, specificity was 97.19%. The traditional logistic regression AUC was 77.4%, accuracy was about 77.73%, sensitivity was 47.15%, specificity was 92.12%.

CONCLUSION

This study showed that disc herniation type (extrusion, sequestration), Modic changes (type II), a large sROM, a large FO and high FI were independent risk factors for reoperation in LDH patients after PELD. The prediction efficiency of XGBoost model was higher than traditional Logistic regression analysis model.

The inflammatory response, a mixed blessing for muscle homeostasis and plasticity

Skeletal muscle makes up almost half the body weight of heathy individuals and is involved in several vital functions, including breathing, thermogenesis, metabolism, and locomotion. Skeletal muscle exhibits enormous plasticity with its capacity to adapt to stimuli such as changes in mechanical loading, nutritional interventions, or environmental factors (oxidative stress, inflammation, and endocrine changes). Satellite cells and timely recruited inflammatory cells are key actors in muscle homeostasis, injury, and repair processes. Conversely, uncontrolled recruitment of inflammatory cells or chronic inflammatory processes leads to muscle atrophy, fibrosis and, ultimately, impairment of muscle function. Muscle atrophy and loss of function are reported to occur either in physiological situations such as aging, cast immobilization, and prolonged bed rest, as well as in many pathological situations, including cancers, muscular dystrophies, and several other chronic illnesses. In this review, we highlight recent discoveries with respect to the molecular mechanisms leading to muscle atrophy caused by modified mechanical loading, aging, and diseases. We also summarize current perspectives suggesting that the inflammatory process in muscle homeostasis and repair is a double-edged sword. Lastly, we review recent therapeutic approaches for treating muscle wasting disorders, with a focus on the RANK/RANKL/OPG pathway and its involvement in muscle inflammation, protection and regeneration processes.

Age-Related Differences in Intermuscular Coherence EMG-EMG of Ankle Joint Antagonist Muscle Activity during Maximal Leaning

BACKGROUND

Intermuscular synchronization is one of the fundamental aspects of maintaining a stable posture and is of great importance in the aging process. This study aimed to assess muscle synchronization and postural stabilizer asymmetry during quiet standing and the limits of stability using wavelet analysis. Intermuscular synchrony and antagonistic sEMG-sEMG (surface electromyography) coherence asymmetry were evaluated in the tibialis anterior and soleus muscles.

METHODS

The study involved 20 elderly (aged 65 ± 3.6) and 20 young (aged 21 ± 1.3) subjects. The task was to perform a maximum forward bend in a standing position. The prone test was divided into three phases: quiet standing (10 s), dynamic learning, and maintenance of maximum leaning (20 s). Wavelet analysis of coherence was performed in the delta and beta bands.

RESULTS

Young subjects modulated interface coherences to a greater extent in the beta band. Analysis of postural stability during standing tasks showed that only the parameter R2b (the distance between the maximal and minimal position central of pressure), as an indicator for assessing the practical limits of stability, was found to be significantly associated with differences in aging.

CONCLUSION

The results showed differences in the beta and delta band oscillations between young and older subjects in a postural task involving standing quietly and leaning forward.

Assessment of selected muscles reactivity in the lower spinal segment

Background: Lumbar spine pain is now a common affliction. In 90% of cases, the pain is of ambiguous and multicausal etiology, described as non-specific lower back pain (NLBP). Various models of this dysfunction were examined. The most popular model presents the pain as a result of an insult and secondary to changes in tension and lumbar muscles degeneration. There is no unequivocal solution concerning the cause of lumbar spine pain in the literature. Aim of the study: To examine the differences in muscles reactivity in the lumbar region in cases who suffer from lumbar spine pain in comparison to otherwise healthy controls. Material and methods: In total, 50 participants (24 men and 26 women) aged 18–45, including 24 people with pain, and 26 without ailments were included in the study. The visual analogue scale was used to measure pain intensity. The participants were assessed to determine the reactivity of the soft tissues of the lumbar part of the body. Selected muscles of this area were examined using a myotonometer, which shows five parameters relevant to viscoelastic tissues. Results: There were significant differences in the level of the pain (p<0.001), hypokinesia of the left abdominal rectus (p<0.05), asymmetry indicators for the creep parameter of the erector spinalis and abdominal external oblique muscle, and the stiffness of abdominal rectus (p<0.05). No significant differences for the remaining parameters were found. Conclusions: Tissue reactivity of selected muscles of the lumbar spine shows slight differences because of pain afflictions occurring in this area.

Reliability and validity of manual palpation for the assessment of patients with low back pain: a systematic and critical review

BACKGROUND

Static or motion manual palpation of the low back is commonly used to assess pain location and reproduction in low back pain (LBP) patients. The purpose of this study is to review the reliability and validity of manual palpation used for the assessment of LBP in adults.

METHOD

We systematically searched five databases from 2000 to 2019. We critically appraised internal validity of studies using QAREL and QUADAS-2 instruments. We stratified results using best-evidence synthesis. Validity studies were classified according to Sackett and Haynes.

RESULTS

We identified 2023 eligible articles, of which 14 were low risk of bias. Evidence suggests that reliability of soft tissue structures palpation is inconsistent, and reliability of bony structures and joint mobility palpation is poor. We found preliminary evidence that gluteal muscle palpation for tenderness may be valid in differentiating LBP patients with and without radiculopathy.

CONCLUSION

Reliability of manual palpation tests in the assessment of LBP patients varies greatly. This is problematic because these tests are commonly used by manual therapists and clinicians. Little is known about the validity of these tests; therefore, their clinical utility is uncertain. High quality validity studies are needed to inform the clinical use of manual palpation tests.

Perception of musculoskeletal pain in the state of confinement: associated factors

OBJECTIVE

to describe the perception of musculoskeletal pain in the population and how the state of confinement (adopted as a measure to control contagion by COVID-19) has interfered with it, as well as identifying the sociodemographic, occupational, physical, and psychosocial factors involved.

METHOD

an observational, cross-sectional and analytical study, with simple random probabilistic sampling, aimed at residents in Spain over 18 years old during the confinement period. An ad hoc survey was conducted, consisting in 59 items.

RESULTS

a total of 3,247 surveys were answered. Persistent musculoskeletal pain or significant episodes thereof increased 22.2% during confinement. The main location was the spine (49.5%). The related factors were decreased physical activity, increased seated position, and use of electronic devices. The psychological impact of confinement was also related to the perception of musculoskeletal pain.

CONCLUSION

the state of confinement causes an increase in the perception of musculoskeletal pain. The identification of a particularly sensitive population profile, as well as that of the related factors, allows establishing multidisciplinary approaches in health promotion.

Trunk muscle activity during pressure feedback monitoring among individuals with and without chronic low Back pain

BACKGROUND

Pressure biofeedback unit (PBU) is a widely used non-invasive device to assist core muscle training by providing pressure feedback. The aim this study was to compare the muscle activities of transverse abdominis (TA) and multifidus (MF) at different target pressures (50, 60 and 70 mmHg) of PBU between individuals with and without cLBP.

METHODS

Twenty-two patients with chronic LBP (cLBP) and 24 age matched healthy individuals were recruited. Electromyography (EMG) signals were recorded from the TA and MF muscles while the TA and MF were contracted to achieve PBU pressure value of 50, 60 and 70 mmHg in random order. The average EMG amplitude (AEMG) of 3 replicate trials was used in the analysis after normalization to %MVIC. %MVIC is defined as the mean of the three AEMG divided by the AEMG of MVIC. Two-way ANOVA was performed to assess the effects of groups (healthy and cLBP) and the three different target pressures of PBU. Independent sample t-test was conducted to compare between the two groups. Spearman's correlation analysis was performed in the cLBP group to determine potential correlations between EMG activity, NPRS and ODI.

RESULTS

The %MVIC of the TA and MF in the cLBP group were higher than the control group at each pressure value (P<0.05). During maximal voluntary isometric contraction (MVIC) of TA and MF, compared with healthy groups, cLBP subjects showed a decrease (TA mean = 47.61 μV; MF mean = 42.40 μV) in EMG amplitudes (P ≤ 0.001). The MVIC of MF was negatively correlated with Numerical Pain Rating Scale (r = - 0.48, P = 0.024) and Oswestry Disability Index (r = - 0.59, P = 0.004).

CONCLUSIONS

We measured the trunk muscles activities at different PBU pressure values, which allows the individual to estimate trunk muscle contraction via PBU. Clinicians may be able to confer the data obtained through EMG recordings to adjust the exercise intensity of PBU training accordingly.

Longitudinal Analysis of Paraspinal Muscle Cross-Sectional Area During Early Adulthood - A 10-Year Follow-Up MRI Study

Only a few previous studies have investigated paraspinal musculature (i.e., multifidus (MF), psoas major (PSM), erector spinae (ES)) in longitudinal, population-based settings. This study aimed to evaluate changes in the cross-sectional area (CSA) of the paraspinal muscles between the ages of 20 and 30 years. The study population consisted of a sub-cohort from the Northern Finland Birth Cohort 1986 (n = 298; 156 men, 142 women). Baseline magnetic resonance imaging was performed at a mean age of 21.3 years and follow-up imaging at 30.6 years. The CSA measurements were performed by tracing the paraspinal muscle outlines individually (MF, ES, PM) and all combined (total muscle area (TMA)) at the L4 cranial endplate level. The longitudinal data analysis was performed using generalized estimating equations modelling. The CSA of MF and ES increased during the follow-up among both sexes (men: MF + 5.7%, p < 0.001; ES + 2.7%, p = 0.001; and women: MF + 10.5%, p < 0.001; ES 9.2%, p = 0.001). The CSA of PM decreased among men (PM −4.0%, p < 0.001) but not among women (PM + 0.5%, p = 0.553). TMA increased significantly only among women (men: +0.5%, p = 0.425; women: +6.5%, p < 0.001). The increases in ES and TMA were more distinct among women than men (p < 0.001). Our study demonstrated clear age- and sex-related changes in paraspinal muscle size in early adulthood.