The relationship between functionality and erector spinae activity in patients with specific low back pain during dynamic and static movements

The Application of Surface Electromyography Technology in Evaluating Paraspinal Muscle Function

Surface electromyography (sEMG) has emerged as a valuable tool for assessing muscle activity in various clinical and research settings. This review focuses on the application of sEMG specifically in the context of paraspinal muscles. The paraspinal muscles play a critical role in providing stability and facilitating movement of the spine. Dysfunctions or alterations in paraspinal muscle activity can lead to various musculoskeletal disorders and spinal pathologies. Therefore, understanding and quantifying paraspinal muscle activity is crucial for accurate diagnosis, treatment planning, and monitoring therapeutic interventions. This review discusses the clinical applications of sEMG in paraspinal muscles, including the assessment of low back pain, spinal disorders, and rehabilitation interventions. It explores how sEMG can aid in diagnosing the potential causes of low back pain and monitoring the effectiveness of physical therapy, spinal manipulative therapy, and exercise protocols. It also discusses emerging technologies and advancements in sEMG techniques that aim to enhance the accuracy and reliability of paraspinal muscle assessment. In summary, the application of sEMG in paraspinal muscles provides valuable insights into muscle function, dysfunction, and therapeutic interventions. By examining the literature on sEMG in paraspinal muscles, this review offers a comprehensive understanding of the current state of research, identifies knowledge gaps, and suggests future directions for optimizing the use of sEMG in assessing paraspinal muscle activity.

The Observable Movement Quality scale for patients with low back pain (OMQ-LBP): validity and reliability in a primary care setting of physical therapy

BACKGROUND

The Observable Movement Quality scale for patients with low back pain (OMQ-LBP) is a newly developed measurement instrument for use in primary care settings of physical and exercise therapists to assess movement quality (MQ) of patients with low back pain (LBP).

OBJECTIVE

This study aims to determine validity, reliability and feasibility of the OMQ-LBP. The OMQ-LBP consists of a standardized movement circuit (performed twice) consisting of five daily activities problematic for LBP patients, which are scored with an 11-item observation list.

METHODS

Construct validity was determined by testing seven hypotheses on associations between constructs (n = 85 patients with LBP) and four hypotheses on known group differences (n = 85 patients with LBP and n = 63 healthy controls; n = 35 matched participant-patients having VAS-pain ≥ 20 mm during and/or after both circuits and healthy controls). Internal consistency was analyzed with Cronbach's alpha (n = 85 patients with LBP). For inter- and intra-rater reliability Intraclass Correlation Coefficient (ICC) values were examined (n = 14 therapists: seven primary care physical therapists and seven exercise therapists). Additionally, content validity and feasibility were determined using thematic analysis of a brief interview with participants, patients (n = 38) and therapists (n = 14).

RESULTS

After Bonferroni correction 2/7 associations between constructs and 2/4 significant group differences were confirmed. Cronbach's alpha was 0,79. The ICC-values of interrater reliability of the OMQ-LBP total score and the duration score were 0.56 and 0.99 and intra-rater reliability 0.82 and 0,93, respectively. Thematic analysis revealed five themes. Three themes elucidate that both patients and therapists perceived the content of the OMQ-LBP as valid. The fourth theme exhibits that OMQ-LBP provides a clear and unambiguous language for MQ in patients with LBP. Theme 5 depicts that the OMQ-LBP seems feasible, but video recording is time-consuming.

CONCLUSIONS

The OMQ-LBP is a promising standardized observational assessment of MQ during the five most problematic daily activities in patients with LBP. It is expected that uniform and objective description and evaluation of MQ add value to clinical reasoning and facilitate uniform communication with patients and colleagues.

The relationship between spinal alignment and activity of paravertebral muscle during gait in patients with adult spinal deformity: a retrospective study

BACKGROUND

Spinal alignment in patients with adult spinal deformity (ASD) changes between rest and during gait. However, it remains unclear at which point the compensated walking posture breaks down and how muscles respond. This study used time-synchronized electromyography (EMG) to investigate the relationship between dynamic spinal alignment and muscle activity during maximum walking duration to reveal compensation mechanisms.

METHODS

This study collected preoperative three-dimensional gait analysis data from patients who were candidates for corrective surgery for ASD from April 2015 to May 2019. We preoperatively obtained dynamic spinal alignment parameters from initiation to cessation of gait using a motion capture system with time-synchronized surface integrated EMG (iEMG). We compared chronological changes in dynamic spinal alignment parameters and iEMG values 1) immediately after gait initiation (first trial), 2) half of the distance walked (half trial), and 3) immediately before cessation (last trial).

RESULTS

This study included 26 patients (22 women, four men) with ASD. Spinal sagittal vertical axis distance during gait (SpSVA) increased over time (first vs. half vs. last, 172.4 ± 74.8 mm vs. 179.9 ± 76.8 mm vs. 201.6 ± 83.1 mm; P < 0.001). Cervical paravertebral muscle (PVM) and gluteus maximus activity significantly increased (P < 0.01), but thoracic and lumbar PVM activity did not change. Dynamic spinal alignment showed significant correlation with all muscle activity (cervical PVM, r = 0.41-0.54; thoracic PVM, r = 0.49-0.66; gluteus maximus, r = 0.54-0.69; quadriceps, r = 0.46-0.55) except lumbar PVM activity.

CONCLUSION

Spinal balance exacerbation occurred continuously in patients with ASD over maximum walking distance and not at specific points. To maintain horizontal gaze, cervical PVM and gluteus maximus were activated to compensate for a dynamic spinal alignment change. All muscle activities, except lumbar PVM, increased to compensate for the spinal malalignment over time.

Manual handling amongst physiotherapists: Analysis of intra-shift variations in pain, fatigue and movement

BACKGROUND

Manual handling injuries amongst physiotherapists are common and the need to improve our understanding of causal influences is imperative.

OBJECTIVE

The objective was to determine whether intra-shift variations in manual handling task performance occurred in our cohort, which may inform mechanisms underpinning related injuries.

METHODS

We used motion capture, force plate dynamics and electromyography to identify variations in task performance, loading forces and muscle activity, during the performance of one static and one dynamic standardized manual handling task, pre- and post-shift, by 40 physiotherapists. Participants also rated their pain and fatigue on a visual analogue scale (VAS). Statistical analysis utilised paired samples Student's t tests.

RESULTS

Significant differences were seen in the EMG activity in the quadriceps during the static task only. No significant differences were seen for any of the kinematic variables. Significant differences in fatigue (p < 0.005) were seen between the pre- and post-shift sessions. Notably, there were significant differences in pain between the pre- and post-shift sessions in the static (p < 0.01) and dynamic tasks (p < 0.05). This increase in pain was at a level which impacted on function.

CONCLUSION

Whilst significant variations in task performance were not observed, our findings indicate that physiotherapists frequently experience task-related pain towards the end of their shift. Contemporary research indicates that frequent transient low back pain may transition to a chronic disabling condition, as such we posit that the effects of intra-shift pain, and its causative factors, should be more widely considered in a 'whole-of-job' approach to mitigating risk in this demographic.

Neuroendocrine effects of a single bout of functional and core stabilization training in women with chronic nonspecific low back pain: A crossover study

Exercise-induced hypoalgesia (EIH) is characterized as the pain reduction after an exercise session and it seems to be related to the release of plasma β-endorphin. In this sense, the core stabilization training (CT) has been suggested for patients with chronic nonspecific low back pain (CNSLBP), but it is unclear whether it induces EIH. Patients with CNSLBP have neuromotor dysfunctions that can affect the performance of functional tasks, thus, performing functional training (FT) could improve motor control and promote EIH, since functional training uses multi-joint exercises that aim to improve the functionality of actions performed in daily life. EIH is usually assessed using quantitative sensory tests (QST) such as conditioned pain modulation, pressure pain threshold, and temporal summation. Thus, the sum of parameters from quantitative sensory tests and plasma β-endorphin would make it possible to understand what the neuroendocrine effects of FT and CT session are. Our study compared the acute effect of CT and FT on the EIH and plasma β-endorphin release, and correlated plasma β-endorphin with quantitative sensory testing in patients with CNSLBP. Eighteen women performed two training sessions (CT and FT) with an interval of 48 h between sessions. EIH was assessed by QST and plasma β-endorphin levels. Results showed that only FT significantly increased plasma β-endorphin (FT p < 0.01; CT p = 0.45), which correlated with pain pressure threshold (PPT) and conditioned pain modulation (CPM). However, QST values were not different in women with CNSLBP after CT or FT protocols. Plasma β-endorphin correlated with PPT and CPM, however, the same did not occur with a temporal summation.

Do people with low back pain walk differently? A systematic review and meta-analysis

BACKGROUND

The biomechanics of the trunk and lower limbs during walking and running gait are frequently assessed in individuals with low back pain (LBP). Despite substantial research, it is still unclear whether consistent and generalizable changes in walking or running gait occur in association with LBP. The purpose of this systematic review was to identify whether there are differences in biomechanics during walking and running gait in individuals with acute and persistent LBP compared with back-healthy controls.

METHODS

A search was conducted in PubMed, CINAHL, SPORTDiscus, and PsycINFO in June 2019 and was repeated in December 2020. Studies were included if they reported biomechanical characteristics of individuals with and without LBP during steady-state or perturbed walking and running. Biomechanical data included spatiotemporal, kinematic, kinetic, and electromyography variables. The reporting quality and potential for bias of each study was assessed. Data were pooled where possible to compare the standardized mean differences (SMD) between back pain and back-healthy control groups.

RESULTS

Ninety-seven studies were included and reviewed. Two studies investigated acute pain and the rest investigated persistent pain. Nine studies investigated running gait. Of the studies, 20% had high reporting quality/low risk of bias. In comparison with back-healthy controls, individuals with persistent LBP walked slower (SMD = -0.59, 95% confidence interval (95%CI): -0.77 to -0.42)) and with shorter stride length (SMD = -0.38, 95%CI: -0.60 to -0.16). There were no differences in the amplitude of motion in the thoracic or lumbar spine, pelvis, or hips in individuals with LBP. During walking, coordination of motion between the thorax and the lumbar spine/pelvis was significantly more in-phase in the persistent LBP groups (SMD = -0.60, 95%CI: -0.90 to -0.30), and individuals with persistent LBP exhibited greater amplitude of activation in the paraspinal muscles (SMD = 0.52, 95%CI: 0.23-0.80). There were no consistent differences in running biomechanics between groups.

CONCLUSION

There is moderate-to-strong evidence that individuals with persistent LBP demonstrate differences in walking gait compared to back-healthy controls.

Quantifying the stiffness of lumbar erector spinae during different positions among participants with chronic low back pain

Objective

The purposes of this study were to (1) detect the intra- and inter-reliabilities of the lumbar erector spinae stiffness by MyotonPRO among participants with chronic lower back pain (CLBP); (2) compare the muscle stiffness between pain and non-pain sides during different positions; (3) explore the correlation between intensity of pain and muscle stiffness.

Design

Twenty participants with CLBP were recruited and the stiffness measurements were carried out by two experienced physiotherapists (operators Ⅰ and Ⅱ). Each participant was evaluated by the operatorⅠ in different postures (static prone and sitting). After a 5-day interval, the same participant was reassessed by the operatorⅠ in the static prone posture. For the inter-rater reliability test, each participant was quantified by both operators once, with 30 minutes between the measurements on the same day. The intensity of pain was evaluated using a 0–10 visual analog scale (VAS).

Results

The intra- and inter-rater reliabilities were excellent (ICC = 0.88–0.99). The MDC values ranged from 25.03 to 86.26 N/m. Examples of Bland-Altman plots showed good agreement. The erector spinae stiffness on the painful sides was higher with a marked increase in the sitting position (P < .05) when compared with the non-painful side. However, there was no significant difference in the prone position (P > .05). The intensity of pain among adults with CLBP was not associated with muscle stiffness of the lumbar erector spinae muscle.

Conclusions

Our findings indicated that the MyotonPRO is a feasible device in quantifying the stiffness of the lumbar erector spinae muscle in patients with CLBP. Meanwhile, the erector spinae stiffness on the painful sides was higher in the sitting when compared with the non-painful side.

Cerebral mechanism of opposing needling for managing acute pain after unilateral total knee arthroplasty: study protocol for a randomized, sham-controlled clinical trial

Background

Opposing needling is a unique method used in acupuncture therapy to relieve pain, acting on the side contralateral to the pain. Although opposing needling has been used to treat pain in various diseases, it is not clear how opposing needling affects the activity of the central nervous system to relieve acute pain. We herein present the protocol for a randomized sham-controlled clinical trial aiming to explore the cerebral mechanism of opposing needling for managing acute pain after unilateral total knee arthroplasty (TKA).

Methods

This is a randomized sham-controlled single-blind clinical trial. Patients will be allocated randomly to two parallel groups (A: opposing electroacupuncture group; B: sham opposing electroacupuncture group). The Yinlingquan (SP9), Yanglingquan (GB34), Futu (ST32), and Zusanli (ST36) acupoints will be used as the opposing needling sites in both groups. In group A, the healthy lower limbs will receive electroacupuncture, while in group B, the healthy lower limbs will receive sham electroacupuncture. At 72 h after unilateral TKA, patients in both groups will begin treatment once per day for 3 days. Functional magnetic resonance imaging will be performed on all patients before the intervention, after unilateral TKA, and at the end of the intervention to detect changes in brain activity. Changes in pressure pain thresholds will be used as the main outcome for the improvement of knee joint pain. Secondary outcome indicators will include the visual analogue scale (including pain during rest and activity) and a 4-m walking test. Surface electromyography, additional analgesia use, the self-rating anxiety scale, and the self-rating depression scale will be used as additional outcome indices.

Discussion

The results will reveal the influence of opposing needling on cerebral activity in patients with acute pain after unilateral TKA and the possible relationship between cerebral activity changes and improvement of clinical variables, which may indicate the central mechanism of opposing needling in managing acute pain after unilateral TKA.

Trial registration

Study on the brain central mechanism of opposing needling analgesia after total kneearthroplasty based on multimodal MRI ChiCTR2100042429. Registered on January 21, 2021

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06066-6.

Vibrating Exercise Equipment in Middle-Age and Older Women with Chronic Low Back Pain and Effects on Bioelectrical Activity, Range of Motion and Pain Intensity: A Randomized, Single-Blinded Sham Intervention Study

Simple Summary

Physical activity is often recommended as part of the management of chronic low back pain, which is one of the most common musculoskeletal disorders. Vibrating exercise equipment is used despite little scientific evidence to support its effectiveness in the prevention and treatment of musculoskeletal problems. The aim of this study was to evaluate the efficiency of using vibrating exercise equipment in women with chronic low back pain. Here, 92 women aged 49–80 years were assigned to one of two groups: the experimental and the control group. The intervention consisted of aerobic exercises with specific handheld equipment. Both groups performed physical activity twice weekly for 10 weeks. The erector spinae muscles’ bioelectrical activity, the lumbar range of motion and pain intensity were measured in all participants at baseline and after 10 weeks. Compared with baseline measures, there was a significant decrease in the bioelectrical activity of the erector spinae muscles during flexion movement, rest at maximum flexion, extension movement and rest in a prone position; an increase in the lumbar range of motion and a decrease in pain intensity following a program of physical activity with vibrating exercise equipment. No significant changes were found in intergroup comparisons; however, physical activity with vibrating exercise equipment could be a prospective strategy for increasing lumbar range of motion and decreasing pain and erector spinae muscle activity in people with chronic low back pain.

Abstract

Background: Chronic low back pain (CLBP) is one of the most common musculoskeletal disorders. Physical activity (PA) is often recommended as part of the management of CLBP, but to date, no one particular exercise has been shown to be superior. Vibrating exercise equipment (VEE) is widely available and used despite little scientific evidence to support its effectiveness in the prevention and treatment of musculoskeletal problems. The aim of this study was to evaluate the efficiency of using VEE compared with sham-VEE in women with CLBP. Methods: A randomized (1:1 randomization scheme) single-blinded sham-controlled intervention study was conducted. Through simple randomization, 92 women aged 49–80 years were assigned to one of two groups: VEE (the experimental group) and sham-VEE (the control group). The VEE and sham-VEE intervention consisted of aerobic exercises with specific handheld equipment. Both groups performed physical activity twice weekly for 10 weeks. The erector spinae muscles’ bioelectrical activity (using an eight-channel electromyograph MyoSystem 1400L), lumbar range of motion (Schober’s test) and pain intensity (visual analog scale) were measured in all participants at baseline and after 10 weeks. Results: There was a significant decrease in the bioelectrical activity of the erector spinae muscles during flexion movement (left: Me = 18.2 before; Me = 14.1 after; p = 0.045; right: Me = 15.4 before; Me = 12.6 after; p = 0.010), rest at maximum flexion (left: Me = 18.1 before; Me = 12.5 after; p = 0.038), extension movement (right: Me = 21.8 before; Me = 20.2 after; p = 0.031) and rest in a prone position (right: Me = 3.5 before; Me = 3.2 after; 0.049); an increase in lumbar range of motion (Me = 17.0 before; Me = 18.0 after; p = 0.0017) and a decrease in pain intensity (Me = 4.0 before; Me = 1.0 after; p = 0.001) following a program of PA in the VEE group. Conclusions: No significant changes were found in intergroup comparisons. The beneficial changes regarding decreased subjective pain sensation in the VEE and sham-VEE groups may be due to participation in systematic physical activity. However, PA with vibrating exercise equipment could be a prospective strategy for increasing lumbar range of motion and for decreasing pain and erector spinae muscle activity in people with CLBP.

Detection of Typical Compensatory Movements during Autonomously Performed Exercises Preventing Low Back Pain (LBP)

With the growing number of people seeking medical advice due to low back pain (LBP), individualised physiotherapeutic rehabilitation is becoming increasingly relevant. Thirty volunteers were asked to perform three typical LBP rehabilitation exercises (Prone-Rocking, Bird-Dog and Rowing) in two categories: clinically prescribed exercise (CPE) and typical compensatory movement (TCM). Three inertial sensors were used to detect the movement of the back during exercise performance and thus generate a dataset that is used to develop an algorithm that detects typical compensatory movements in autonomously performed LBP exercises. The best feature combinations out of 50 derived features displaying the highest capacity to differentiate between CPE and TCM in each exercise were determined. For classifying exercise movements as CPE or TCM, a binary decision tree was trained with the best performing features. The results showed that the trained classifier is able to distinguish CPE from TCM in Bird-Dog, Prone-Rocking and Rowing with up to 97.7% (Head Sensor, one feature), 98.9% (Upper back Sensor, one feature) and 80.5% (Upper back Sensor, two features) using only one sensor. Thus, as a proof-of-concept, the introduced classification models can be used to detect typical compensatory movements in autonomously performed LBP exercises.

Effect of dry needling on lumbar muscle stiffness in patients with low back pain: A double blind, randomized controlled trial using shear wave elastography

Background: Dry needling treatment focuses on restoring normal muscle function in patients with musculoskeletal pain; however, little research has investigated this assertion. Shear wave elastography (SWE) allows quantification of individual muscle function by estimating both resting and contracted muscle stiffness.Objective: To compare the effects of dry needling to sham dry needling on lumbar muscle stiffness in individuals with low back pain (LBP) using SWE.Methods: Sixty participants with LBP were randomly allocated to receive one session of dry needling or sham dry needling treatment to the lumbar multifidus and erector spinae muscles on the most painful side and spinal level. Stiffness (shear modulus) of the lumbar multifidus and erector spinae muscles was assessed using SWE at rest and during submaximal contraction before treatment, immediately after treatment, and 1 week later. Treatment effects were estimated using linear mixed models.Results: After 1 week, resting erector spinae muscle stiffness was lower in individuals who received dry needling than those that received sham dry needling. All other between-groups differences in muscle stiffness were similar, but non-significant.Conclusion: Dry needling appears to reduce resting erector spinae muscle following treatment of patients with LBP. Therefore, providers should consider the use of dry needling when patients exhibit aberrant stiffness of the lumbar muscles.

"It's All Sort of Cool and Interesting…but What Do I Do With It?" A Qualitative Study of Stroke Survivors' Perceptions of Surface Electromyography

Background: Stroke is one of the most common neurologic injuries worldwide. Over decades, evidence-based neurorehabilitation research and advancements in wireless, wearable sensor design have supported the deployment of technologies to facilitate recovery after stroke. Surface electromyography (sEMG) is one such technology, however, clinical application remains limited. To understand this translational practice gap and improve clinical uptake, it is essential to include stakeholder voices in an analysis of neurorehabilitation practice, the acceptability of current sEMG technologies, and facilitators and barriers to sEMG use in the clinic and the community. The purpose of this study was to foreground the perspectives of stroke survivors to gain a better understanding of their experiences in neurorehabilitation, the technologies they have used during their recovery, and their opinions of lab-designed and commercially-available sEMG systems. Methods: A qualitative, phenomenological study was completed. In-depth, semi-structured interviews were conducted with eight stroke survivors (age range 49-78 years, 6 months to 12 years post-stroke) and two caregivers from a large metropolitan region. A demonstration of four sEMG systems was provided to gather perceptions of sensor design, features and function, and user interface. Interviews were audio-recorded, transcribed verbatim, and coded for analysis using constant comparison until data saturation was reached. Results: Three themes emerged from the data: (1) "Surface EMG has potential….but…" highlights the recognition of sEMG as a valuable tool but reveals a lack of understanding and need for clear meaning from the data; (2) "Tracking incremental progress over days or years is important" highlights the persistence of hope and potential benefit of sEMG in detecting small changes that may inform neurorehabilitation practice and policy; and (3) "Neurorehabilitation technology is cumbersome" highlights the tension between optimizing therapy time and trying new technologies, managing cost, logistics and set-up, and desired technology features. Conclusion: Further translation of sEMG technology for neurorehabilitation holds promise for stroke survivors, but sEMG system design and user interface needs refinement. The process of using sEMG technology and products must be simple and provide meaningful insight to recovery. Including stroke survivors directly in translational efforts is essential to improve uptake in clinical environments.

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.

Sensor Technologies to Manage the Physiological Traits of Chronic Pain: A Review

Non-oncologic chronic pain is a common high-morbidity impairment worldwide and acknowledged as a condition with significant incidence on quality of life. Pain intensity is largely perceived as a subjective experience, what makes challenging its objective measurement. However, the physiological traces of pain make possible its correlation with vital signs, such as heart rate variability, skin conductance, electromyogram, etc., or health performance metrics derived from daily activity monitoring or facial expressions, which can be acquired with diverse sensor technologies and multisensory approaches. As the assessment and management of pain are essential issues for a wide range of clinical disorders and treatments, this paper reviews different sensor-based approaches applied to the objective evaluation of non-oncological chronic pain. The space of available technologies and resources aimed at pain assessment represent a diversified set of alternatives that can be exploited to address the multidimensional nature of pain.