Reliability of Surface Electromyography in the Assessment of Paraspinal Muscle Fatigue: An Updated Systematic Review

Reliability, validity and normative data of the timed water swallow test accompanied by sEMG

PURPOSE

Swallowing disorders are highly interrelated with increased morbidity and mortality rates; therefore, early detection is crucial. Most screening tools rely on subjective observation, thus making objective assessment tools more vital. Timed Water Swallowing Test (TWST) is a screening tool used in the field providing quantitative data. This study aimed to investigate the swallowing parameters in a wide age range by using TWST and to expand the already existing normative data pool accordingly. It is also aimed to examine the reliability of the TWST and assess its validity in stroke survivors.

MATERIALS AND METHODS

This study had a cross-sectional design. TWST carried out simultaneously along with surface EMG and laryngeal sensor on 196 healthy subjects aged 10 to 80 for normative data. Also, TWST carried out 30 patients having a history of recent stroke. Test-retest and inter-rater scoring analysis were used for reliability purposes, while Gugging Swallowing Screen (GUSS) test was used for validity purposes. Additionally, the correlations between the participants' TWST scores and GUSS scores were examined using the Spearman correlation coefficient.

RESULTS

The normative TWST data of healthy participants are tabulated and presented and their average swallowing capacity was found 13.73 ml/s. Furthermore, the mean swallowing capacity of stroke survivors was found 4.61 ml/s. As a result of validity analyses, a statistically strong and significant relationship was found between GUSS and TWST parameters (r = 0.775, p < 0.001). Intraclass correlation coefficient (ICC) and correlation values were found between moderate to good agreement between test-retest measurement (ICC = 0.563 to 0.891, p < 0.05). Also, the agreement between the raters was found to be significant (ICC = 0.949 to 0.995, p < 0.05).

CONCLUSION

TWST is a valid and reliable screening tool to evaluate dysphagia on given population. Although the test's performance on healthy individuals is adequate, more research is still needed to confirm that it can be used as a screening tool for stroke.

The clinical utility and reliability of surface electromyography in individuals with chronic low back pain: A systematic review

Chronic low back pain (CLBP) is a common disorder worldwide, affecting young and old adults alike. Kinematic studies of lumbar-pelvic mobility allied with surface electromyogram (sEMG) can assist in the assessment and management of CLBP. This systematic review aimed to synthesise the evidence relating to the diagnostic accuracy and reliability of the surface electromyogram in chronic low back pain patients during flexion-extension-relaxation tasks. Five databases (PubMed, Scopus, Web of Science, Embase and CINAHL) were searched for eligible studies from inception to March 2024. The risk of bias assessment for the included studies was conducted using the QUADAS-2 tool. Studies included adults (≥18 years) with CLBP > 3 months, reported diagnostic accuracy or reliability measures for sEMG during flexion-extension-relaxation tasks. Eleven studies were included in our systematic review. The risk of bias was found to be high for patient selection, reference standard and flow and timing domains with low risk of bias for the index test domain in most of the included studies. For diagnostic accuracy, six studies reported values ranging between 56-99 % indicating poor to excellent accuracy levels. Four studies reported values between 76-100 % for sensitivity and 65-100 % for specificity indicating sufficient to excellent accuracy levels. Seven studies reported moderate to excellent reliability levels, ranging between 0.66-0.99. This systematic review found the diagnostic accuracy and reliability of sEMG in CLBP patients to range from poor to excellent levels. This systematic review adds knowledge for practitioners and clinicians regarding the use of sEMG during forward, flexion and relaxation tasks/movements.

Erector Spinae Muscle Activation During Forward Movement in Individuals With or Without Chronic Lower Back Pain: A Systematic Review and Meta-analysis

Objective

To investigate the differences between erector spinae muscle activation in healthy individuals and patients with Chronic Lower Back Pain (CLBP) by conducting (a) systematic review and (b) meta-analysis.

Data Sources

PubMed, ScienceDirect, SPORTDiscus, and Google Scholar were used to conduct the searches, which included studies up to the 31st of March 2023 with no start date specified.

Study Selection

Any study otherwise meeting eligibility criteria was included if it reported either (1) a standard mean difference effect size; or (2) the means, SDs, and sample sizes for both the patient group and the comparator group.

Data Extraction

A total of 7 case control trials were used for the systematic review and meta-analysis.

Data Synthesis

The systematic review and meta-analysis revealed that total standardized mean difference in erector spinae muscle activation between healthy individuals vs patients with CLBP expressed in % maximum voluntary isometric contraction was 0.48 (95% confidence interval=0.21-0.74; P<.001) with the heterogeneity being I2=0% (P=.890). The electromyography (EMG) outputs showed significant differences in activation levels between the healthy and CLBP cohorts (P<.001).

Conclusions

A small effect size was found in the meta-analysis. The muscle activation levels of the erector spinae during forward propulsion were higher in CLBP individuals compared with healthy cohorts. The findings provide more clarity about the muscles that were the focus of previous research, what procedures were used to evaluate muscular contributions and what speeds the participants were moving at during the test sessions. Given the limited methodological quality of the included studies, the findings should be interpreted with caution. Future research should evaluate the effect of other factors such as walking distance and any changes in walking surfaces and gradients (ie, non-flat surfaces).

[Motion analysis systems in research and for practicing orthopedists]

BACKGROUND

Complex biomechanical motion analysis can provide relevant information for a variety of orthopedic problems. When purchasing motion analysis systems, in addition to the classical measurement quality criteria (validity, reliability, objectivity), spatial and temporal conditions, as well as the requirements for the qualification of the measuring personnel should be considered.

APPLICATION

In complex movement analysis, systems are used to determine kinematics, kinetics and muscle activity (electromyography). This article gives an overview of methods of complex biomechanical motion analysis for use in orthopaedic research or for individual patient care. In addition to the use for pure movement analysis, the use of movement analysis methods in the field of biofeedback training is discussed.

ACQUISITION

For the specific acquisition of motion analysis systems, it is recommended to contact professional societies (e.g., the German Society for Biomechanics),universities with existing motion analysis facilities or distributors in the field of biomechanics.

Effect of intervertebral disc degeneration on the stomatognathic system function in adults

OBJECTIVE

To analyze the electromyographic activity (EMG) and thermographic patterns of the masseter and temporalis muscles and pressure of the orofacial tissues in individuals with intervertebral disc degeneration (IDD).

METHODS

This study had two distinct groups: with IDD (n = 16) and controls (n = 16). EMG at rest, protrusion, right and left laterality, and maximum voluntary contraction were evaluated. Tongue, orbicularis oris, and buccinator muscles pressures were measured by Iowa Oral Performance Instrument. The thermographic patterns were analyzed using infrared thermography.

RESULTS

Comparisons between groups showed significant differences regarding at rest [right (p = 0.05) and left (p = 0.05) masseter and right temporal (p = 0.05)], orofacial tissue pressure [tongue (p = 0.001), orbicularis oris (p = 0.01), and buccinator (p = 0.0001)], but no significant differences for the thermographic patterns.

CONCLUSION

IDD modifies the functionality of the craniomandibular complex, influencing the performance of the stomatognathic system.

Associations between Deformation of the Thoracolumbar Fascia and Activation of the Erector Spinae and Multifidus Muscle in Patients with Acute Low Back Pain and Healthy Controls: A Matched Pair Case-Control Study

Background: The thoracolumbar fascia (TLF) is thought to play a role in the development of LBP, but it is not yet clear which factor of TLF changes is a cause and which is an effect. Therefore, some studies used the cross-correlation function (CCR) to reveal time-dependent relationships between biomechanical and neuromotor factors. Methods: Ten patients with acute low back pain (aLBP) were matched to healthy controls. Simultaneous recording of surface electromyography (sEMG) of the erector spinae and multifidus muscle (ESM) and dynamic ultrasound (US) images of TLF deformation were performed during trunk extension. CCR functions and Granger causality (GC) were used to describe the relationship between the two measures. Results: CCR time lags were significant higher in the aLBP group (p = 0.04). GC showed a direct effect of TLF deformation on ESM activation only in the aLBP group (p < 0.03). Conclusions: The results suggest that in aLBP, ESM activity is significantly affected by TLF, whereas this relationship is completely random in healthy subjects studied with CCR and GC comparisons of dynamic US imaging and sEMG data signals. Fascia-related disturbances in neuromotor control, particularly due to altered muscle spindle functions, are suspected as a possible mechanism behind this.

Between/within-session reliability of spinal kinematic and lumbar muscle activity measures in patients with chronic low back pain and asymptomatic individuals

BACKGROUND

Longitudinal research is required to better understand the role of spinal movement alterations in chronic low back pain (CLBP). To this end, it is critical to assess the between-session reliability of spinal movement measures.

RESEARCH QUESTION

What is the within/between-session reliability of spinal movement measures in patients with CLBP and asymptomatic controls?

METHODS

Spinal movement was recorded prospectively during two sessions, a week apart, for 20 patients with CLBP (60% male; 40.0 ± 12.3 years old) and 20 asymptomatic individuals (55% male; 38.2 ± 10.9 years old). Sagittal-plane angular amplitude and angular velocity at the lower lumbar, upper lumbar, lower thoracic and upper thoracic joints, as well as maximal erector spinae activity were measured during five daily-activity tasks. In addition, task-independent measures were obtained by averaging the measures across tasks. The Intraclass Correlation Coefficient (ICC 2,1) and the minimal detectable change (MDC) were calculated. Pearson correlation was used to compare task-independent and task-specific measures.

RESULTS

Between-session ICCs in patients with CLBP were mostly moderate to good for maximal angular amplitude and erector spinae activity measures. Lower ICCs were observed for range of angular motion and angular velocity measures (42% of ICCs < 0.5). Median MDCs were 9.6°, 18.3°/s and 1.0% for angular amplitude, angular velocity and erector spinae activity measures, respectively. The reliability of task-independent and task-specific measures was strongly correlated (r = 0.91, p < 0.001).

SIGNIFICANCE

Sagittal-plane maximal angular amplitude and erector spinae activity measures during various daily-activity tasks demonstrated mostly moderate to good between-session ICCs. However, relatively large MDCs suggested that important changes are needed to be detectable. Task-independent measures reported similarly acceptable ICCs than task-specific measures, supporting their use to describe spinal movement.

No alteration of back muscle oxygenation during isometric exercise in individuals with non-specific low back pain

The aim of our study was (I) To compare back muscle oxygenation and perfusion as well as Biering–Sorensen muscle endurance (BSME) test holding times between chronic non-specific low back pain (CNSLBP) patients and asymptomatic controls matched for age, body mass index (BMI), sex and physical activity, and (II) to investigate factors associated with BSME holding times. Muscle perfusion (tHb) and oxygenation (SmO₂) were measured by near-infrared spectroscopy (NIRS) based oximetry in three back muscles during the BSME. Reliability of tHb and SmO₂ was assessed in a separate sample. BSME holding time and SmO₂ were compared between patients (n = 45) and controls (n = 45) and factors associated with BSME holding time were assessed using multiple linear regression. Reliability for SmO₂ was excellent (ICC = 0.87–0.99). THb showed poor to moderate reliability and was not further used. Groups differed for BSME holding time (P = 0.03), pain intensity (P ≤ 0.0005) and subcutaneous tissue thickness (P = 0.01) but not for NIRS measures. Physical activity and BMI were associated with BSME holding times. Insufficient muscle oxygenation does not seem to be a major factor contributing to CNSLBP. Future investigation should evaluate other determinants of BSME holding times, such as motivation and recruitment of auxiliary muscles.

Clinical utility and reproducibility of surface electromyography in individuals with chronic low back pain: a protocol for a systematic review and meta-analysis

INTRODUCTION

Chronic low back pain (CLBP) is one of the most common disorders presenting in primary healthcare. Kinematic studies of low lumbar pelvic mobility allied with surface electromyography (sEMG) may assist in the assessment and management of CLBP. However, the applicability in the use of sEMG in the clinical setting remains uncertain. In this protocol, we aim to review the clinical utility and reproducibility of the sEMG component of these kinematic studies in patients with CLBP.

METHODS AND ANALYSIS

This protocol was informed by the Preferred Reporting Items for Systematic review and Meta-Analysis Protocols (PRISMA-P) and results will be reported in line with the PRISMA. Searches will be conducted on PubMed, Scopus, Web of Science, Embase, CINAHL and Google Scholar databases, along with a comprehensive review of grey literature. Two reviewers will conduct the searches and independently screen them, according to title and abstract. Two independent reviewers will then assess the full-text versions of those selected articles and assess the risk of bias using the defined protocol inclusion criteria. The risk of bias within the studies included will be assessed via the Quality Assessment of Diagnostic Accuracy Studies tool, V.2 and the Grading of Recommendations Assessment, Development and Evaluation guidelines will be used to assess certainty of evidence for recommendations based on the risk of bias findings. Meta-analysis will be conducted where appropriate on groups of studies with low heterogeneity. In instances of higher heterogeneity, meta-synthesis will instead be completed, comparing results in terms of increased or decreased clinical utility and/or reproducibility of sEMG.

ETHICS AND DISSEMINATION

Ethics approval was not required for this research. It is anticipated that the results will influence the use, interpretation and further development of sEMG in management and assessment of these patients.

PROSPERO REGISTRATION NUMBER

CRD42021273936.

EFFECT OF FATIGUE ON EXPLOSIVE STRENGTH AND MUSCLE ARCHITECTURE OF THE VASTUS LATERALIS

ABSTRACT Introduction: There has been little research on changes in rate of torque development (RTD) and muscle architecture. This study evaluated the effect of fatigue on RTD and muscle architecture of the vastus lateralis (VL). Methods: Seventeen volunteers (25.5 ± 6.2 years; 177.2 ± 12.9 cm; 76.4 ± 13.1 kg) underwent isokinetic knee extension assessment at 30°/s to obtain the peak torque (PT-ISK), before and after a set of intermittent maximal voluntary isometric contractions (MVIC) (15 reps – 3 s contraction, 3 s rest) used to promote muscle fatigue, monitored by the median frequency (MDF) of the electromyography from the VL, rectus femoris and vastus medialis muscles. Before and after the fatigue protocol, ultrasound images of the VL were obtained to measure muscle thickness (MT), fascicle length (FL), and fascicle angle (FA). The peak isometric torque (PT-ISM) and the RTDs in 50 ms windows were calculated for each MVIC. The RTDs were reported as absolute values and normalized by the PT-ISM. Results: Fatigue was confirmed due to significant reductions in MDF in all three muscles. After the fatigue protocol, the PT-ISK was reduced from 239.0±47.91 to 177.3±34.96 Nm, and the PT-MVIC was reduced from 269.5±45.63 to 220.49±46.94 Nm. All the RTD absolute values presented significant change after the fatigue protocol. However, the normalized RTD did not demonstrate any significant differences. No significant differences were found in the muscle architecture of the VL. Conclusions: The reduction in explosive strength occurred concomitantly with the reduction in maximum strength, as evidenced by the lack of changes in normalized TDT. Level of Evidence III.

Paraspinal strength and electromyographic fatigue in patients with sub-acute back pain and controls: Reliability, clinical applicability and between-group differences

BACKGROUND

Paraspinal muscle strength and fatigue are considered important in low back pain (LBP) prevention and rehabilitation. High reliability of paraspinal strength and electromyographic (EMG)-fatigue parameters has not been universally reported. Moreover, the discriminative validity of these parameters requires further exploration, under the threat of potentially poor reliability of the methods examined.

AIM

To investigate the reliability and discriminative validity of paraspinal strength and EMG-related fatigue in subjects with recurrent LBP and healthy participants.

METHODS

Test-retest measurements were performed in 26 healthy and 66 LBP volunteers, for reliability. Paraspinal isometric maximal and mean strength were determined with a maximum voluntary isometric contraction (MVIC) protocol, performed in a custom-made device. For the fatigue test, participants performed a 60% MIVC level continuous isometric contraction of the paraspinals, in conjunction with EMG analysis from 4 muscle sites of the lumbar spine. Initial median frequency (IMF), the median frequency slope (MFslope), as well as the root mean square (RMS) slope EMG parameters were used as fatigue measures. Data were analysed with repeated measures ANOVA for test-retest differences. For reliability, the intraclass correlation coefficient (ICC_3,1), standard error of the measurement (SEM) and the smallest detectable difference (SDD) were reported. Group-related differences for fatigue measures were analysed with a Multivariate Analysis of Covariance, with age, weight and strength as covariates.

RESULTS

Isometric strength presented statistically significant between-day differences (P < 0.01), however these did not exceed 10% (healthy: 7.2%/LBP-patients: 9.7%) and ICC reliability values were excellent, yet test-retest error was increased for the patient group (healthy: ICC_3,1: 0.92-0.96, SEM: 5.72-5.94 Hz, SDD: 18.51%-18.57%/LBP-patients: ICC_3,1: 0.91-0.96, SEM: 6.49-6.96, SDD: 30.75%-31.61%). For the frequency data, IMF reliability was excellent (healthy: ICC_3,1: 0.91-0.94, SEM: 3.45-7.27 Hz, SDD: 9.56%-20.14%/patients: ICC_3,1: 0.90-0.94, SEM: 6.41-7.59 Hz, SDD: 17.75%-21.02%) and of MF raw and normalised slopes was good (healthy: ICC_3,1: 0.78-0.82, SEM: 4.93-6.02 Hz, SDD: 13.66-16.67%/LBP-patients: ICC_3,1: 0.83-0.85, SEM: 6.75-7.47 Hz, SDD: 18.69%-20.69%). However, the reliability for RMS data presented unacceptably high SDD values and were not considered further. For discriminative validity, less MVIC and less steep MFslopes were registered for the patient group (P < 0.01).

CONCLUSION

Reliability and discriminative ability of paraspinal strength and EMG-related frequency parameters were demonstrated in healthy participants and patients with LBP.

Changes in synchronization of the motor unit in muscle fatigue condition during the dynamic and isometric contraction in the Biceps Brachii muscle

The fatigue-induced neuromuscular mechanism remains to be fully elucidated. So far, the macroscopic mechanism using global surface electromyogram (sEMG) has been widely investigated. However, the microscopic mechanism using high-level neural information based on motor unit (MU) spike train from the spinal cord lacks attention, especially for the conditions under dynamic contraction task. The synchronization of the MU spike train is generally assumed to be an excellent indicator to represent the activities of spinal nerves. Accordingly, this study employed synchronization of MU spike train decomposed from high-density sEMG (HD-sEMG) to investigate the fatigue condition in muscular contractions within the Biceps Brachii muscle under both isometric and dynamic contraction tasks, giving a complete picture of the microscopic fatigue mechanism. We compared the synchronization of MU in Delta (1-4 Hz), alpha (8-12 Hz), Beta (15-30 Hz), and Gamma (30-60 Hz) frequency bands during the fatigue condition induced by different contractions. Our results showed that MU synchronization increased significantly (p<0.05) in all frequency bands across the two contraction tasks. The results indicate that the microscopic fatigue mechanism of Biceps Brachii muscle does not vary due to different contraction tasks.

Trunk muscle endurance, strength and flexibility in rural subsistence farmers and urban industrialized adults in western Kenya

OBJECTIVES

High trunk muscle endurance, strength, and moderate flexibility reportedly help maintain musculoskeletal health, but there is evidence for tradeoffs among these variables as well as sex differences in trunk muscle endurance and strength. To test if these observations extend similarly to both men and women in nonindustrial and industrial environments, we investigated intra-individual associations and group and sex differences in trunk muscle endurance, strength, and flexibility among 74 (35 F, 39 M; age range: 18-61 years) adults from the same Kalenjin-speaking population in western Kenya. We specifically compared men and women from an urban community with professions that do not involve manual labor with rural subsistence farmers, including women who frequently carry heavy loads.

METHODS

Trunk muscle endurance, strength, and flexibility were measured with exercise tests and electromyography (EMG).

RESULTS

We found a positive correlation between trunk extensor strength and endurance (R = .271, p ≤ .05) and no associations between strength or endurance and flexibility. Rural women had higher trunk extensor and flexor endurance, EMG-determined longissimus lumborum endurance, and trunk extensor strength than urban women (all p ≤ .05). Rural women had higher trunk extensor and flexor endurance than rural men (both p ≤ .05). Urban women had lower trunk flexor and extensor endurance than urban men (both p ≤ .01).

CONCLUSIONS

High levels of physical activity among nonindustrial subsistence farmers, particularly head carrying among women, appear to be associated with high trunk muscle endurance and strength, which may have important benefits for helping maintain musculoskeletal health.

Patients with Axial Spondyloarthritis Show an Altered Flexion/Relaxation Phenomenon

Axial spondyloarthritis (axSpA) is a chronic rheumatic disease characterized by the presence of inflammatory back pain. In patients with chronic low back pain, the lumbar flexion relaxation phenomenon measured by surface electromyography (sEMG) differs from that in healthy individuals. However, sEMG activity in axSpA patients has not been studied. The purpose of this study was to analyze the flexion relaxation phenomenon in axSpA patients. A study evaluating 39 axSpA patients and 35 healthy controls was conducted. sEMG activity at the erector spinae muscles was measured during lumbar full flexion movements. sEMG activity was compared between axSpA patients and the controls, as well as between active (BASDAI ≥ 4) and non-active (BASDAI < 4) patients. The reliability (using intraclass correlation coefficients (ICC)), criterion validity and discriminant validity using the area Under the curve (AUC) for the inverse flexion/relaxation ratio (1/FRR) were evaluated. Significant differences (p < 0.05) were observed between axSpA patients and the control group in lumbar electric activity, especially during flexion, relaxation, and extension and in FRR and 1/FRR (0.66 ± 0.39 vs. 0.25 ± 0.19, respectively). In addition, significant differences were found between active and non-active but also between non-active and healthy subjects. The sEMG showed good reliability (ICC > 0.8 for 1/FRR) and criterion validity. ROC analysis showed good discriminant validity for axSpA patients (AUC = 0.835) vs. the control group using 1/FRR. An abnormal flexion/relaxation phenomenon exists in axSpA patients compared with controls. sEMG could be an additional objective tool in the evaluation of patient function and disease activity status.

An International Continence Society (ICS) report on the terminology for pelvic floor muscle assessment

INTRODUCTION

The terminology for female and male pelvic floor muscle (PFM) assessment has expanded considerably since the first PFM function and dysfunction standardization of terminology document in 2005. New terms have entered assessment reports, and new investigations to measure PFM function and dysfunction have been developed. An update of this terminology was required to comprehensively document the terms and their definitions, and to describe the assessment method and interpretation of the finding, to standardize assessment procedures and aid diagnostic decision making.

METHODS

This report combines the input of members of the Standardisation Committee of the International Continence Society (ICS) Working Group 16, with contributions from recognized experts in the field and external referees. A logical, sequential, clinically directed assessment framework was created against which the assessment process was mapped. Within categories and subclassifications, each term was assigned a numeric coding. A transparent process of 12 rounds of full working group and external review was undertaken to exhaustively examine each definition, plus additional extensive internal development, with decision making by collective opinion (consensus).

RESULTS

A Terminology Report for the symptoms, signs, investigations, and diagnoses associated with PFM function and dysfunction, encompassing 185 separate definitions/descriptors, has been developed. It is clinically based with the most common assessment processes defined. Clarity and user-friendliness have been key aims to make it interpretable by clinicians and researchers of different disciplines.

CONCLUSION

A consensus-based Terminology Report for assessment of PFM function and dysfunction has been produced to aid clinical practice and be a stimulus for research.

Overuse-Related Injuries of the Musculoskeletal System: Systematic Review and Quantitative Synthesis of Injuries, Locations, Risk Factors and Assessment Techniques

Overuse-related musculoskeletal injuries mostly affect athletes, especially if involved in preseason conditioning, and military populations; they may also occur, however, when pathological or biological conditions render the musculoskeletal system inadequate to cope with a mechanical load, even if moderate. Within the MOVIDA (Motor function and Vitamin D: toolkit for risk Assessment and prediction) Project, funded by the Italian Ministry of Defence, a systematic review of the literature was conducted to support the development of a transportable toolkit (instrumentation, protocols and reference/risk thresholds) to help characterize the risk of overuse-related musculoskeletal injury. The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) approach was used to analyze Review papers indexed in PubMed and published in the period 2010 to 2020. The search focused on stress (overuse) fracture or injuries, and muscle fatigue in the lower limbs in association with functional (biomechanical) or biological biomarkers. A total of 225 Review papers were retrieved: 115 were found eligible for full text analysis and led to another 141 research papers derived from a second-level search. A total of 183 papers were finally chosen for analysis: 74 were classified as introductory to the topics, 109 were analyzed in depth. Qualitative and, wherever possible, quantitative syntheses were carried out with respect to the literature review process and quality, injury epidemiology (type and location of injuries, and investigated populations), risk factors, assessment techniques and assessment protocols.

Effects of kinesio taping on neck-shoulder discomfort and EMG responses during smartphone texting in healthy young adults

BACKGROUND

While kinesio taping (KT) is used in several clinical settings to correct posture and reduce pain, KT effects during smartphone texting are unknown.

OBJECTIVE

To investigate the effects among healthy young adults of KT on neck-shoulder discomfort and electromyographic (EMG) responses of neck and upper trunk muscles during smartphone texting.

METHODS

Twenty-four participants performed a 30-minute texting task on a smartphone using both hands at two separate times under one of two conditions: KT on the right shoulder and no taping. Neck-shoulder discomfort was assessed, along with the normalized root mean square (NRMS) and normalized median frequency (NMF) of the right cervical erector spinae (CES), lower trapezius (LT), and serratus anterior (SA).

RESULTS

Compared to baseline, both groups had significantly greater neck-shoulder discomfort, and NRMS and NMF of all muscles (p < 0.001) after performing a 30-minute texting task. Comparing between groups, the KT group experienced significantly less neck-shoulder discomfort, and demonstrated delayed deterioration of NRMS and NMF of right CES and LT muscles (p < 0.05).

CONCLUSIONS

During smartphone texting, KT on the shoulder decreased neck-shoulder discomfort and delayed reduction of activation and fatigue of neck and upper trunk muscles among healthy young adults.

Electromyography activities in patients with lower lumbar disc herniation

BACKGROUND

Lumbar disc herniation (LDH) can affect lower limb muscle function resulting in an abnormal gait. This study aims to use surface electromyography (SEMG) to evaluate patients with L4/L5 and L5/S1 LDH throughout muscle movement.

METHODS

Twenty L4/L5 LDH patients (L5 Group), twenty L5/S1 LDH patients (S1 Group), and twenty healthy controls (Healthy) were recruited for the study. SEMG of bilateral tibialis anterior (TA) and lateral gastrocnemius (LG) muscles of patients were recorded using the DELSYS Wireless EMG System (TrignoTM Wireless Systems, Delsys Inc., USA). Root-mean-square (RMS), mean power frequency (MPF), and median frequency (MF) were compared between bilateral limbs in each participant.

RESULTS

Reduced MPF and MF was found in TA measurements of the L5 Group and LG measurements of the S1 Group. The MPF and MF of the TA of symptomatic limbs of the L5 Group were reduced when compared to asymptomatic limbs (p= 0.006, p= 0.012, p< 0.05), and there were no significant differences in LG measurements (p> 0.05). The LG MPF and MF of the S1 Group in symptomatic limbs were reduced when compared to asymptomatic limbs (p= 0.006, p= 0.017, p< 0.05), and there were no significant differences in TA measurements (p> 0.05). Although there were no significant differences in RMS between bilateral limbs of the L5 and S1 Groups, we found some changes in RMS curves. First, compared to asymptomatic limbs of L4/L5LDH patients, β-peaks in the TA of symptomatic limbs appeared earlier. Second, two peaks in the LG of symptomatic limbs were found in L5/S1 LDH patients.

CONCLUSION

TA is affected in patients with LDH of L4/L5, and LG is affected in patients with LDH of L5/S1. As demonstrated, SEMG can identify LDH-related muscle dysfunction.

Surface EMG in Clinical Assessment and Neurorehabilitation: Barriers Limiting Its Use

This article addresses the potential clinical value of techniques based on surface electromyography (sEMG) in rehabilitation medicine with specific focus on neurorehabilitation. Applications in exercise and sport pathophysiology, in movement analysis, in ergonomics and occupational medicine, and in a number of related fields are also considered. The contrast between the extensive scientific literature in these fields and the limited clinical applications is discussed. The "barriers" between research findings and their application are very broad, and are longstanding, cultural, educational, and technical. Cultural barriers relate to the general acceptance and use of the concept of objective measurement in a clinical setting and its role in promoting Evidence Based Medicine. Wide differences between countries exist in appropriate training in the use of such quantitative measurements in general, and in electrical measurements in particular. These differences are manifest in training programs, in degrees granted, and in academic/research career opportunities. Educational barriers are related to the background in mathematics and physics for rehabilitation clinicians, leading to insufficient basic concepts of signal interpretation, as well as to the lack of a common language with rehabilitation engineers. Technical barriers are being overcome progressively, but progress is still impacted by the lack of user-friendly equipment, insufficient market demand, gadget-like devices, relatively high equipment price and a pervasive lack of interest by manufacturers. Despite the recommendations provided by the 20-year old EU project on "Surface EMG for Non-Invasive Assessment of Muscles (SENIAM)," real international standards are still missing and there is minimal international pressure for developing and applying such standards. The need for change in training and teaching is increasingly felt in the academic world, but is much less perceived in the health delivery system and clinical environments. The rapid technological progress in the fields of sensor and measurement technology (including sEMG), assistive devices, and robotic rehabilitation, has not been driven by clinical demands. Our assertion is that the most important and urgent interventions concern enhanced education, more effective technology transfer, and increased academic opportunities for physiotherapists, occupational therapists, and kinesiologists.

Reliability of surface electromyography for the gluteus medius muscle during gait in people with and without chronic nonspecific low back pain

The purpose of this study was to determine the intratester reliability of surface electromyography (EMG) assessment of the gluteus medius muscle in healthy people and people with chronic nonspecific low back pain (CNLBP) during barefoot walking. Gluteus medius muscle activity was measured twice in 40 people without and 30 people with CNLBP approximately 7 days apart. Walking gluteus medius muscle activity was normalised to maximal voluntary isometric contractions during side-lying hip abduction with manual resistance. Good intratester reliability (ICC > 0.75) was found for mean, peak, and peak to peak amplitude for healthy people. Only mean amplitude demonstrated good intratester reliability in those with CNLBP. Peak amplitude and peak to peak amplitude of the gluteus medius muscle of those with CNLBP, and the time of peak amplitude in both groups, demonstrated moderate reliability (ICC ranged from 0.50 to 0.58). Moderate to large standard error of measurement and minimal detectable change values were reported for outcome measurements. These results suggest that potentially large levels of random error can occur between sessions. Future research can build on this study for those with pathology and attempt to establish change values for EMG that are clinically meaningful.

Effects of Dry Needling Technique Into Trigger Points of the Sternocleidomastoid Muscle in Migraine Headache: A Randomized Controlled Trial

OBJECTIVE

The study aimed to investigate the effect of dry needling into trigger points of the sternocleidomastoid muscle in migraine headache patients.

DESIGN

Forty subjects with a migraine headache, originating from myofacial trigger points into the sternocleidomastoid muscle (20 subjects in dry needling group and 20 subjects in control group) volunteered to participate in this study. The subjects in the treatment group received three sessions of dry needling in the myofascial trigger point region. Headache frequency, headache intensity, headache duration, drug consumption, muscle thickness, pressure pain threshold, and cervical range of motion were assessed before, immediately after intervention, and at 1-mo follow-up period. In addition, this article was extracted from Iranian Register of Clinical Trials Number IRCT20171219037956N1.

RESULTS

The experimental group showed significant reduction in the headache parameters immediately after the intervention and at 1-mo follow-up, as compared with the control group. The pressure pain threshold of sternocleidomastoid muscle, cervical range of motion, and muscle thickness significantly increased in the dry needling group in comparison with the control group (P < 0.001).

CONCLUSIONS

The application of dry needling technique caused an improvement in symptoms of migraine patients. Therefore, this technique may be prescribed for treating migraine patients with myofacial trigger points in the sternocleidomastoid muscle.

Investigating differences in trunk muscle activity in non-specific chronic low back pain subgroups and no-low back pain controls during functional tasks: a case-control study

BACKGROUND

Trunk muscle dysfunction is often regarded as a key feature of non-specific chronic low back pain (NSCLBP) despite being poorly understood and variable with increases, decreases and no change in muscle activity reported. Differences in thoraco-lumbar kinematics have been observed in motor control impairment NSCLBP subgroups (Flexion Pattern, Active Extension Pattern) during static postures and dynamic activities. However, potential differences in muscle activity during functional tasks has not been established in these subgroups to date.

METHODS

A case-control study design recruited 50 NSCLBP subjects (27 Flexion Pattern, 23 Active Extension Pattern) and 28 healthy individuals. Surface electromyography determined muscle activity during functional tasks: reaching upwards, step-down, step-up, lifting and replacing a box, stand-to-sit, sit-to-stand, bending to retrieve (and returning from retrieving) a pen from the floor. Normalised (% sub-maximal voluntary contraction) mean amplitude electromyography of bilateral musculature (transversus abdominis/internal oblique, external oblique, superficial lumbar multifidus and longissimus thoracis) was analysed using Kruskal-Wallis and post-hoc Mann-Whitney U tests.

RESULTS

Transversus abdominis/internal oblique activity was significantly increased in the Flexion Pattern group compared to controls during stand-to-sit (p = 0.009) on the left side only. External oblique activity was significantly greater in the Active Extension Pattern group compared to controls during box lift (p = 0.016) on the right side only. Significantly greater activity was identified in the right Superficial lumbar multifidus during step up (p = 0.029), reach up (p = 0.013) and box replace (p = 0.007) in the Active Extension Pattern group compared to controls. However left-sided superficial lumbar multifidus activity was significantly greater in the Flexion Pattern group (compared to controls) only during stand-to-sit (p = 0.009). No significant differences were observed in longissimus thoracis activity bilaterally during any task. No significant differences between NSCLBP subgroups were observed.

CONCLUSIONS

Muscle activity in these NSCLBP subgroups appears to be highly variable during functional tasks with no clear pattern of activity identified. The findings reflect inconsistencies and variability in trunk muscle activity previously observed in these NSCLBP subgroups. Further work evaluating ratios of muscle activity and changes in muscle activity throughout task duration is warranted.

Reliability of Real-time Ultrasound Imaging for the Assessment of Trunk Stabilizer Muscles: A Systematic Review of the Literature

Rehabilitative ultrasound (US) imaging is one of the popular methods for investigating muscle morphologic characteristics and dimensions in recent years. The reliability of this method has been investigated in different studies. As studies have been performed with different designs and quality, reported values of rehabilitative US have a wide range. The objective of this study was to systematically review the literature conducted on the reliability of rehabilitative US imaging for the assessment of deep abdominal and lumbar trunk muscle dimensions. The PubMed/MEDLINE, Scopus, Google Scholar, Science Direct, Embase, Physiotherapy Evidence, Ovid, and CINAHL databases were searched to identify original research articles conducted on the reliability of rehabilitative US imaging published from June 2007 to August 2017. The articles were qualitatively assessed; reliability data were extracted; and the methodological quality was evaluated by 2 independent reviewers. Of the 26 included studies, 16 were considered of high methodological quality. Except for 2 studies, all high-quality studies reported intraclass correlation coefficients (ICCs) for intra-rater reliability of 0.70 or greater. Also, ICCs reported for inter-rater reliability in high-quality studies were generally greater than 0.70. Among low-quality studies, reported ICCs ranged from 0.26 to 0.99 and 0.68 to 0.97 for intra- and inter-rater reliability, respectively. Also, the reported standard error of measurement and minimal detectable change for rehabilitative US were generally in an acceptable range. Generally, the results of the reviewed studies indicate that rehabilitative US imaging has good levels of both inter- and intra-rater reliability.

A Comparison of the Abdominal and Lumbar Multifidus Muscle Size in Patients With Lumbar Spondylolisthesis and Healthy Patients at Rest and During Contraction Using Ultrasonography

OBJECTIVE

Using ultrasonography, this study investigated the abdominal and lumbar multifidus muscle size in patients with lumbar spondylolisthesis compared with healthy patients at rest and during contraction.

METHODS

This research was a nonexperimental, analytic case-control study. Ultrasound imaging was used to assess the thickness of the abdominal and lumbar multifidus muscles in 25 healthy patients and 25 patients with spondylolisthesis. For the purpose of this study, both men and women, aged 30 to 70 years, were recruited from physiotherapy clinics affiliated with the University of Social Welfare and Rehabilitation Sciences, Tehran, Iran. Measurements were taken at rest and during contraction.

RESULTS

There was a significant difference in abdominal and lumbar multifidus muscle size between the healthy and spondylolisthesic groups, both at rest and contraction (P < .05 in all instances). No significant difference was found between the right and left for all measurements (P > .05).

CONCLUSION

Patients with spondylolisthesis had smaller stabilizer muscle thickness at rest and during contraction compared with the healthy group.

Upper extremity surface electromyography signal changes after laparoscopic training

Introduction

Objective measures of laparoscopic skill in training are lacking.

Aim

To evaluate the changes in the surface electromyography (sEMG) signal during laparoscopic training, and to link them to intracorporeal knot tying.

Material and methods

Ten right-handed medical students (6 female), aged 25 ±0.98, without training in laparoscopy, were enrolled in the study. With no additional training, they tied intracorporeal single knots for 15 min. Then underwent laparoscopic training and redid the knot tying exercise. During both events, sEMG was recorded from 8 measurement points on the upper extremities and neck bilaterally. We analyzed changes in sEMG resulting from training and tried to find sEMG predictive parameters for higher technical competence defined by the number of knots tied after the training.

Results

The average number of knots increased after the training. Significant decreases in activity after the training were visible for the non-dominant hand deltoid and trapezius muscles. Dominant and non-dominant hands had different activation patterns. Differences largely disappeared after the training. All muscles, except for the dominant forearm and non-dominant thenar, produced a negative correlation between their activities and the number of tied knots. The strongest anticorrelation occurred for the non-dominant deltoid (r = –0.863, p < 0.05). Relatively strong relationships were identified in the case of the non-dominant trapezius and forearm muscles (r = –0.587, r = –0.504).

Conclusions

At least for some muscle groups there is a change in activation patterns after laparoscopic training. Proximal muscle groups tend to become more relaxed and the distal ones become more active. Changes in the non-dominant hand are more pronounced than in the dominant hand.

Feasibility of Muscle Activity Assessment With Surface Electromyography During Bed Cycling Exercise In Intensive Care Unit Patients

Introduction: Intensive care unit (ICU) patients often develop weakness. Rehabilitation is initiated early to prevent physical deterioration, but knowledge of optimal training schedules is lacking. A reliable method to assess muscle activity during exercise is needed. In this study we explored the feasibility of electrical activity measurement by surface electromyography (sEMG) during bed cycling in ICU patients. Methods: SEMG was performed in 9 ICU patients and 6 healthy controls. A standardized 1‐minute incremental resistance bedside cycle ergometer protocol was used. Results: The median cycle time was 5.3 minutes in patients and 12.0 minutes in controls. The maximum sEMG increased in both groups; the minimal sEMG activity remained the same in patients, whereas an increase in the control group was found. Discussion: sEMG is feasible and can detect muscle activity during bed cycling in ICU patients. It may be a useful monitoring tool. Repeated measurements could possibly provide information on the effects of training. Muscle Nerve58: 688–693, 2018

Flexion-Relaxation Phenomenon in Children and Adolescents With and Without Nonspecific Chronic Low Back Pain: An Electromyographic and Kinematic Cross-Sectional Comparative Study

STUDY DESIGN

A cross-sectional comparative study.

OBJECTIVE

This study aimed to investigate the flexion-relaxation phenomenon (FRP), in standing trunk flexion and slumped sitting tasks, by comparing children and adolescents suffering from nonspecific chronic low back pain (NSCLBP) with controls (CTRL).

SUMMARY OF BACKGROUND DATA

The absence of the FRP can accurately discriminate adults with NSCLBP from those without during standing trunk flexion and slumped sitting tasks. Even if the FRP has been extensively studied in adults with NSCLBP, only one study has evaluated the FRP in adolescents, during a slumped sitting task, and this suggested that the FRP was also present in adolescents with NSCLBP.

METHODS

Thirty-seven children and adolescents with NSCLBP and 23 CTRL performed standing trunk flexion and slumped sitting tasks. All participants were equipped with surface electromyography (EMG) electrodes on the erector spinae longissimus (ESL) and multifidus (M) muscles and reflective markers on the spinous processes of C7, L1, and S1. Global (C7-S1), thoracic (C7-L1), and lumbar (L1-S1) trunk flexion absolute angle were measured. The FRP was reported using visual inspection and a flexion-relaxation ratio (FRR). A self-reference threshold was used to identify the time of FRP onset. Repeated-measures analysis of variance (ANOVA) was used to determine the main and interaction effects of task, group and muscle on FRR, and the relative maximal angle at FRP onset of the global trunk (C7-S1).

RESULTS

Results showed three main findings: (1) the FRP's low sensitivity in discriminating between NSCLBP and CTRL participants in groups, tasks, or muscles; (2) similar observed maximal flexion angles in both groups during flexion tasks; and (3) similar observed relative maximal global trunk flexion angles at FRP onset in groups, tasks, and muscles.

CONCLUSION

These results are not consistent with the literature on adults and could lead to modified therapeutic management of NSCLBP in children and adolescents.

LEVEL OF EVIDENCE

3.

Identifying Subgroups of Patients With Chronic Nonspecific Low Back Pain Based on a Multifactorial Approach: Protocol For a Prospective Study

Background

Low back pain, especially nonspecific chronic low back pain (LBP), the leading cause of disability worldwide, represents both social and economic problems. Different therapeutic management techniques can be used, but their effects vary. Clinicians and researchers attribute the variation in the efficacy of therapeutic and management techniques to the heterogeneity of the nonspecific chronic low back pain population, and they agree that nonspecific chronic LBP must be subgrouped.

Objective

This study aims to identify nonspecific chronic LBP subgroups based on a multifactorial approach, including biomechanical, physical, and psychosocial data.

Methods

A total of 100 nonspecific chronic LBP patients and 30 healthy participants aged between 18 and 60 years will be recruited for this prospective study. A psychosocial profile will be established using questionnaires on anxiety, depression, functional disability, pain, fear of pain, avoidance belief, and physical activity. A physical capacity evaluation will be conducted. It will evaluate flexibility of the hips, lumbar spine, and lateral thoracolumbar segment, as well as trunk (extensor and flexor) muscle endurance. The subjects will perform functional daily life activities, such as walking, object lifting, forward bending, sit-to-stand, stand-to-sit, balance, and usual postures. Full body kinematics, kinetics, and surface electromyography of the trunk and hip muscles will be assessed during these tasks. The clustering classification methods for the statistical analysis will be determined according to the data and will be used to identify the subgroups of nonspecific chronic LBP patients.

Results

Data collection started in September 2017 and will be completed with the inclusion of all the participants (100 nonspecific chronic LBP and 30 control). The study results will be published in peer-reviewed journals and presented at relevant international conferences.

Conclusions

Numerous studies have showed that the therapeutic management of nonspecific chronic LBP is difficult and has inconstant effects caused by the complexity and heterogeneity of nonspecific chronic LBP. Identifying subgroups with a multifactorial approach is more comprehensive and closer to the pathophysiology of nonspecific chronic LBP. It also represents benefit interests and a challenge both clinically and socially. The perspective of this study is expected to support clinicians for a more adapted therapeutic management for each subgroup.

Normal values of abdominal muscles thickness in healthy children using ultrasonography

Abdominal muscles are one of the important elements to support the lumbar spine. Evaluation of muscle thickness using ultrasonography (US) is considered to be a source of information from muscles characteristics. The purpose of this study was to demonstrate normal reference data of abdominal muscles thickness and subcutaneous fat in adolescents using US. A random sample of 160 healthy adolescents (80 boys and 80 girls) at the age range of 15-18 years was recruited. Three abdominal muscles including Transversus Abdominis (TA), Internal Oblique (IO), External Oblique (EO) and subcutaneous fat (SF) were bilaterally measured using US. The range of normal values for TA muscle thickness was between 2.31 and 2.57 mm, for IO muscle thickness was between 4.02 and 5.15 mm and for EO muscle thickness was between 2.81 and 3.17 mm. The normal patterns of abdominal muscles were found as IO > EO > TA at both sides. Boys were taller, heavier with greater body mass index (BMI) and had larger abdominal muscles thickness than girls. A weak negative correlation was found between age and muscles size [r = (-0.06) - (-0.23), p < .05], but a significant positive correlation was found between BMI and muscle size (r = 0.21-0.68, p < .05). It seems that abdominal muscles thickness in adolescents followed the same pattern of muscle size in adults. BMI appeared to be the best predictor of muscle thickness. However, further studies are recommended to support the findings of the present study.

Is the timed loaded standing test a valid measure of back muscle endurance in people with vertebral osteoporosis?

Timed loaded standing (TLS) is a suggested measure of back muscle endurance for people with vertebral osteoporosis. Surface electromyography revealed back muscles work harder and fatigue during TLS. The test end-point and total time were associated with back fatigue. The findings help demonstrate the concurrent validity of the TLS test.

INTRODUCTION

The TLS test is suggested as a measure of back muscle endurance for patients with vertebral osteoporosis. However, to date, no study has demonstrated that TLS does measure back extensor or erector spinae (ES) muscle endurance. We used surface electromyography (sEMG) to investigate the performance of the thoracic ES muscles during TLS.

METHODS

Thirty-six people with vertebral osteoporosis with a mean age of 71.6 (range 45-86) years participated. sEMG recordings were made of the ES at T3 and T12 bilaterally during quiet standing (QS) and TLS. The relative (%) change in sEMG amplitude between conditions was compared. Fatigue was evaluated by analysing the change in median frequency (MF) of the sEMG signal during TLS, and the correlation between maximal TLS time and rate of MF decline was examined.

RESULTS

Activity in the ES increased significantly during TLS at all electrode locations. During TLS, the MF declined at a mean rate of -24.2% per minute (95% C.I. -26.5 to -21.9%). The MF slope and test time were strongly correlated (r² = 0.71), and at test end, the final MF dropped to an average 89% (95% C.I. 85 to 93%) of initial MF. Twenty-eight participants (78%) reported fatigue was the main reason for stopping, and for eight (22%), it was pain.

CONCLUSIONS

This study demonstrates that TLS challenges the ES muscles in the thoracic region and results in ES fatigue. Endurance time and the point at which the TLS test ends are strongly related to ES fatigue.

Comparative Study of Abdominal Muscle Thickness on Ultrasonography in Healthy Adolescents and Patients With Low Back Pain

OBJECTIVES

Low back pain (LBP) is a common musculoskeletal disorder among different age groups, including adolescents. The purpose of this study was to compare the abdominal muscle thickness between healthy adolescents and those with LBP.

METHODS

One hundred sixty healthy high school adolescents and 80 high school adolescents with LBP participated in the study. All participants were asked to complete a demographic questionnaire and also a visual analog scale and the Oswestry Disability Questionnaire to evaluate the pain intensity and functional disability. Then abdominal muscle thickness was examined with ultrasonography.

RESULTS

The healthy high adolescents included 80 boys and 80 girls, and the adolescents with LBP included 40 boys and 40 girls. The results showed a significant difference between healthy adolescents and those with LBP in terms of abdominal muscle thickness (P < .05). Patients with LBP had smaller abdominal muscles compared with healthy adolescents. No significant difference was found between the groups in terms of the subcutaneous fat dimension (P > .05).

CONCLUSIONS

The thickness of abdominal muscles was lower in adolescents with LBP. Future studies with a larger sample and a wider age range are recommended to support the results of this study.

The Effect of Different Exercise Programs on Size and Function of Deep Cervical Flexor Muscles in Patients With Chronic Nonspecific Neck Pain: A Systematic Review of Randomized Controlled Trials

BACKGROUND

Neck pain is one of the major public health problems, which has a great impact on people's lives.

OBJECTIVES

The purpose of this study was to systematically review published studies conducted on the effect of different exercise programs on activity, size, endurance, and strength of deep cervical flexor (DCF) muscles in patients with chronic neck pain.

METHODS

The PubMed, Science Direct, OVID, Google scholar, Cochrane Library, and Physiotherapy Evidence Databases were searched to determine relevant articles published from 1990 to March 2016. The articles were qualitatively assessed based on the Physiotherapy Evidence Databases scale for randomized controlled trials studies.

RESULTS

Nine articles were identified and evaluated in the final analysis. Four studies had moderate quality, and five studies had good quality. From those nine studies, eight studies gave support to the effectiveness of specific low-load exercise training on DCF muscles parameters, while one study reported no significant difference between this exercise and other cervical exercise programs.

CONCLUSION

The results of reviewed studies are in favor of specific low-load craniocervical flexion exercise, which seems to be a highly effective exercise regimen compared to other types of exercises in improving DCF muscles impairments in patients with chronic neck pain.

The Effect of 2 Different Exercise Programs on Pain Intensity and Muscle Dimensions in Patients With Chronic Low Back Pain: A Randomized Controlled Trial

OBJECTIVES

The purpose of this study was to compare the effect of 2 exercise programs combined with electrotherapy on pain intensity and lumbar stabilizer muscles dimensions in patients with nonspecific chronic low back pain.

METHODS

A randomized controlled clinical trial was performed with 41 patients with chronic LBP. Participants were randomly allocated into 2 groups: an experimental group (n = 20) received stabilization exercises plus electrotherapy, and a control group (n = 21) received routine exercises plus electrotherapy. Pain intensity, using a visual analog scale, and muscle dimensions of both right and left transverse abdominis and lumbar multifidus muscles, using rehabilitative ultrasonography, were assessed before and immediately after 4 weeks of intervention.

RESULTS

Significant improvement was identified after interventions on pain intensity and muscle size measurements in both groups (P < .01 in all instances). The only exception was the right-side lumbar multifidus cross-sectional area of the control group, which was not statistically significant (P = .081). No significant differences were found between the 2 exercise groups on pain intensity and muscle dimensions (P > .05 in all instances).

CONCLUSIONS

The results of this study suggest that a combination of electrotherapy with either routine or stabilization exercise programs may improve pain intensity and muscle dimensions in patients with nonspecific chronic low back pain.

Multifidus muscle size in adolescents with and without back pain using ultrasonography

OBJECTIVE

The purposes of this study were; a) to compare multifidus muscle cross sectional area (CSA) in male adolescents suffering from low back pain (LBP) with healthy male adolescents using ultrasonography (US), and b) to assess the correlation between multifidus muscle size and demographic variables.

METHODS

A random sample of 40 healthy boys (as a control group) and 40 boys with LBP (as an experimental group) at the age range of 15-18 years was recruited in the present cohort study. Multifidus muscle dimensions including CSA, antero-posterior and medio-lateral dimensions were measured at level of L5 in both groups using US.

RESULTS

The results of an independent t-test to compare multifidus muscle size between the experimental and control groups showed a significant difference between the two groups in terms of CSA, antro-posterior and medio-lateral dimensions so that the experimental group had smaller muscle size than the control group. A significant correlation was found between height, weight and body mass index (BMI) and multifidus muscle size, but no significant correlation was observed between age and muscle size. Pain intensity and functional disability index was significantly correlated with muscle size in the experimental group.

CONCLUSIONS

According to the results, multifidus muscle size was decreased in 15-18 years old male adolescents suffering from LBP compared with their healthy counterparts. Further studies are needed to support the findings of the present study.

Uterine and Abdominal Muscle Electromyographic Activities in Control and PCEA-Treated Nulliparous Women During the Second Stage of Labor

OBJECTIVE

Patient-controlled epidural analgesia (PCEA), used to relieve pain during delivery, delays labor but the mechanism is unknown. The aim was to investigate the effects of PCEA on uterine and abdominal muscles electromyographic (EMG) activity during the second stage of labor.

METHODS

This study included 45 nulliparous pregnant women without PCEA, 42 women with standard PCEA treatment given during the first stage of labor and stopped near the end of the first stage, and 22 women with standard PCEA treatment with continued use throughout the first and second stages of labor. The EMG signals were recorded from the abdominal surface using PowerLab hardware and LabChart software (ADInstruments, New South Wales, Australia) and filtered to separate uterine and abdominal EMG. Various EMG burst parameters were obtained.

RESULTS

There are no differences ( P > .05) in the age, body mass index, fetal weight, and Apgar scores between the patients from the various groups. PCEA (both stopped and continued) inhibits ( P < .05) duration, number of bursts, and root mean square of uterine EMG. PCEA also produces statistically significant ( P < .001) reductions in abdominal EMG. The decrease in EMG activity is accompanied by a significant ( P < .001) prolongation of the second stage duration (PCEA continued = 95.08 ± 8.60 minutes, PCEA stopped = 79.39 ± 6.25 minutes, no PCEA = 61.00 ± 7.23 minutes).

CONCLUSION

PCEA suppresses uterine and abdominal muscle EMG during the second stage of labor but inhibition depends upon the treatment schedule. PCEA prolongs the duration of labor by inhibition of uterine and abdominal muscle and neural activity.

Spinal sagittal imbalance in patients with lumbar disc herniation: its spinopelvic characteristics, strength changes of the spinal musculature and natural history after lumbar discectomy

Background

Spinal sagittal imbalance is a widely acknowledged problem, but there is insufficient knowledge regarding its occurrence. In some patients with lumbar disc herniation (LDH), their symptom is similar to spinal sagittal imbalance. The aim of this study is to illustrate the spinopelvic sagittal characteristics and identity the role of spinal musculature in the mechanism of sagittal imbalance in patients with LDH.

Methods

Twenty-five adults with spinal sagittal imbalance who initially came to our clinic for treatment of LDH, followed by posterior discectomy were reviewed. The horizontal distance between C7 plumb line-sagittal vertical axis (C7PL-SVA) greater than 5 cm anteriorly with forward bending posture is considered as spinal sagittal imbalance. Radiographic parameters including thoracic kyphotic angle (TK), lumbar lordotic angle (LL), pelvic tilting angle (PT), sacral slope angle (SS) and an electromyography(EMG) index ‘the largest recruitment order’ were recorded and compared.

Results

All patients restored coronal and sagittal balance immediately after lumbar discectomy. The mean C7PL-SVA and trunk shift value decreased from (11.6 ± 6.6 cm, and 2.9 ± 6.1 cm) preoperatively to (−0.5 ± 2.6 cm and 0.2 ± 0.5 cm) postoperatively, while preoperative LL and SS increased from (25.3° ± 14.0° and 25.6° ± 9.5°) to (42.4° ± 10.2° and 30.4° ± 8.7°) after surgery (P < 0.05). The preoperative mean TK and PT (24.7° ± 11.3° and 20.7° ± 7.8°) decreased to (22.0° ± 9.8° and 15.8 ± 5.5°) postoperatively (P < 0.05). The largest recruitment order on the level of T7-T8, T12-L1 and the herniated level all improved compared with before and after surgery (P < 0.05). All patients have been followed up for more than 2 years. The mean ODI was 77.8 % before surgery to 4.2 % at the final follow-up.

Conclusions

Spinal sagittal imbalance caused by LDH is one type of compensatory sagittal imbalance. Compensatory mechanism of spinal sagittal imbalance mainly includes a loss of lumbar lordosis, an increase of thoracic kyphosis and pelvis tilt. Spinal musculature plays an important role in spinal sagittal imbalance in patients with LDH.

The effectiveness of powered, active lower limb exoskeletons in neurorehabilitation: A systematic review

OBJECTIVE

This review examines the utility of current active, powered, wearable lower limb exoskeletons as aids to rehabilitation in paraplegic patients with gait disorders resulting from central nervous system lesions.

METHODS

The PRISMA guidelines were used to review literature on the use of powered and active lower limb exoskeletons for neurorehabilitative training in paraplegic subjects retrieved in a search of the electronic databases PubMed, EBSCO, Web of Science, Scopus, ProQuest, and Google Scholar.

RESULTS

We reviewed 27 studies published between 2001 and 2014, involving a total of 144 participants from the USA, Japan, Germany, Sweden, Israel, Italy, and Spain. Seventy percent of the studies were experimental tests of safety or efficacy and 29% evaluated rehabilitative effectiveness through uncontrolled (22%) or controlled (7%) clinical trials.

CONCLUSIONS

Exoskeletons provide a safe and practical method of neurorehabilitation which is not physically exhausting and makes minimal demands on working memory. It is easy to learn to use an exoskeleton and they increase mobility, improve functioning and reduce the risk of secondary injury by reinstating a more normal gait pattern. A limitation of the field is the lack of experimental methods for demonstrating the relative effectiveness of the exoskeleton in comparison with other rehabilitative techniques and technologies.

Validity and everyday clinical applicability of lumbar muscle fatigue assessment methods in patients with chronic non-specific low back pain: a systematic review

PURPOSE

This systematic literature review aimed at examining the validity and applicability in everyday clinical rehabilitation practise of methods for the assessment of back muscle fatiguability in patients with chronic non-specific low back pain (CNSLBP).

METHODS

Extensive research was performed in MEDLINE, Cumulative Index of Nursing and Allied Health Literature (CINAHL), Embase, Physiotherapy Evidence Database (PEDro) and Cochrane Central Register of Controlled Trials (CENTRAL) databases from their inception to September 2014. Potentially relevant articles were also manually looked for in the reference lists of the identified publications. Studies examining lumbar muscle fatigue in people with CNSLBP were selected. Two reviewers independently selected the articles, carried out the study quality assessment and extracted the results. A modified Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) scale was used to evaluate the scientific rigour of the selected works.

RESULTS

Twenty-four studies fulfilled the selection criteria and were included in the systematic review. We found conflicting data regarding the validity of methods used to examine back muscle fatigue. The Biering-Sorensen test, performed in conjunction with surface electromyography spectral analysis, turned out to be the most widely used and comparatively, the most optimal modality currently available to assess objective back muscle fatigue in daily clinical practise, even though critical limitations are discussed.

CONCLUSIONS

Future research should address the identification of an advanced method for lower back fatigue assessment in patients with CNSLBP which, eventually, might provide physical therapists with an objective and reliable test usable in everyday clinical practise. Implications for Rehabilitation Despite its limitations, the Biering-Sorensen test is currently the most used, convenient and easily available fatiguing test for lumbar muscles. To increase validity and reliability of the Biering-Sorensen test, concomitant activation of synergistic muscles should be taken into account. Pooled mean frequency and half-width of the spectrum are currently the most valid electromyographic parameters to assess fatigue in chronic non-specific low back pain. Body mass index, grading of pain and level of disability of the study population should be reported to enhance research quality.

Influence of low-level laser therapy on vertical jump in sedentary individuals

Objective

To investigate the effects of low intensity laser (660nm), on the surae triceps muscle fatigue and power, during vertical jump in sedentary individuals, in addition to delayed onset muscle soreness.

Methods

We included 22 sedentary volunteers in the study, who were divided into three groups: G1 (n=8) without performing low intensity laser (control); G2 (n=7) subjected to 6 days of low intensity laser applications; and G3 (n=7) subjected to 10 days of low intensity laser applications. All subjects were evaluated by means of six evaluations of vertical jumps lasting 60 seconds each. In G2 and G3, laser applications in eight points, uniformly distributed directly to the skin in the region of the triceps surae were performed. Another variable analyzed was the delayed onset muscle soreness using the Visual Analog Scale of Pain.

Results

There was no significant difference in fatigue and mechanical power. In the evaluation of delayed onset muscle soreness, there was significant difference, being the first evaluation higher than the others.

Conclusion

The low intensity laser on the triceps surae, in sedentary individuals, had no significant effects on the variables evaluated.

Application of ultrasonography in the assessment of skeletal muscles in children with and without neuromuscular disorders: a systematic review

The purpose of this study was to systematically review published studies (2000-2014) carried out on the application of ultrasonography (US) to evaluation of skeletal muscle size in children with and without neuromuscular disorders. Different databases including PubMed, Science Direct, OVID, MEDLINE, CINAHL, EMBASE, ProQuest and Google Scholar were searched. The key words used were: "children," "ultrasound," "skeletal muscles," "neuromuscular disease," "neurogenic disorders," "spina bifida," "myelomeningocele" and "reliability." Eighteen articles were found to be relevant. Eight studies applied US in combination with additional methods of assessment. Four of the 18 studies did not have a control group. Ten studies applied only US in the assessment of skeletal muscles in children with and without neuromuscular diseases. In 9 studies, there were children ranging widely in age, and in 3 studies US was used to determine normal values for skeletal muscles. According to the results of these 18 reviewed articles, US is an appropriate, reliable and highly predictive method for assessment of skeletal muscles in children.

Test-retest reliability of trunk motor variability measured by large-array surface electromyography

OBJECTIVE

The objective of this study was to evaluate the test-retest reliability of the trunk muscle activity distribution in asymptomatic participants during muscle fatigue using large-array surface electromyography (EMG).

METHODS

Trunk muscle activity distribution was evaluated twice, with 3 to 4 days between them, in 27 asymptomatic volunteers using large-array surface EMG. Motor variability, assessed with 2 different variables (the centroid coordinates of the root mean square map and the dispersion variable), was evaluated during a low back muscle fatigue task. Test-retest reliability of muscle activity distribution was obtained using Pearson correlation coefficients.

RESULTS

A shift in the distribution of EMG amplitude toward the lateral-caudal region of the lumbar erector spinae induced by muscle fatigue was observed. Moderate to very strong correlations were found between both sessions in the last 3 phases of the fatigue task for both motor variability variables, whereas weak to moderate correlations were found in the first phases of the fatigue task only for the dispersion variable.

CONCLUSION

These findings show that, in asymptomatic participants, patterns of EMG activity are less reliable in initial stages of muscle fatigue, whereas later stages are characterized by highly reliable patterns of EMG activity.