Postural Cueing to Increase Lumbar Lordosis Increases Lumbar Multifidus Activation During Trunk Stabilization Exercises: Electromyographic Assessment Using Intramuscular Electrodes

The effect of trunk position and pain location on lumbar extensor muscle recruitment strategies

The aim of this study was to investigate the effect of trunk position and experimental lumbar pain location on lumbar extensor muscle recruitment strategies. Nineteen healthy participants (10 men and 9 women), aged 25.3 ± 4.7 yr, performed isometric back extension contractions in three positions (neutral, 45°, and 90° trunk flexion) and under three conditions (no pain, caudal pain, and cranial pain). Lumbar muscle activation strategies were recorded using high-density surface electromyography. The effect of position and pain condition on muscle activity amplitude and spatial redistributions was assessed. Muscle activity amplitude was 43% higher in 45° trunk flexion than in neutral position on both sides (P < 0.05). In the 90° trunk flexion, participants showed a more lateral spatial distribution than in the 45° trunk flexion on the left side (P < 0.01, 5.4 mm difference) and the neutral position on both sides (P < 0.05, 8.2 mm difference). In the 45° trunk flexion, participants exhibited a more lateral spatial distribution compared with the neutral position on the right side (P < 0.05, 3.7 mm difference). A lateral spatial redistribution of muscle activity was observed in the caudal pain condition compared with the no pain condition on the right side (P < 0.05, 3.0 mm difference). Individual responses to pain varied across all variables. Different trunk positions result in different distributions of activation within the lumbar extensor muscles, possibly based on regional mechanical advantage. No clear indication of location-specific pain adaptation and no effect of task-dependent pain adaptation were found, whereas individual-specific adaptations were observed.NEW & NOTEWORTHY Changes in muscle activity amplitude and spatial redistribution of lumbar extensor muscles were observed in different trunk positions, potentially due to changes in their mechanical advantage. The results complement the current pain-adaptation theory by illustrating individual spatial redistributions of activation within lumbar extensor muscles during pain. The study found no clear indication of location-specific pain adaptation and no effect of task-dependent pain adaptation.

Treatment of Chronic Neck Pain in Patients with Forward Head Posture: A Systematic Narrative Review

(1) Background: Forward head posture (FHP) is one of the most common cervical postural deviations and is characterized by head protrusion or forward head placement in relation to the shoulder in the sagittal plane. Patients with FHP often experience neck pain and disability. The aim of this study was to investigate whether treatment programs are effective in the management of neck pain in patients with FHP. (2) Methods: A MEDLINE (PubMed), Embase, Cochrane Library, and Scopus database search was conducted for English language articles on patients with chronic neck pain and FHP published until 12 April 2023. To identify potentially relevant articles, the following key search phrases were combined: 'forward head posture' and 'pain'. After searching, 2516 potentially relevant articles were identified. After reading the titles and abstracts and assessing their eligibility based on full-text articles, 16 articles were included in this review. (3) Results: Among the 16 studies that investigated the efficacy of treatment programs for managing chronic pain in patients with FHP, 11 investigated the effect of exercise programs, and 5 investigated the effect of manual therapy. Patients reported significant improvement in pain and disability after receiving treatment programs such as corrective postural exercises and special manual therapy techniques. (4) Conclusions: Various treatment programs, including postural corrective exercises and manual therapy, are beneficial for improving pain and disability in patients with FHP.

The relationship between clinical examination measures and ultrasound measures of fascia thickness surrounding trunk muscles or lumbar multifidus fatty infiltrations: An exploratory study

Patients with chronic low back pain (CLBP) exhibit remodelling of the lumbar soft tissues such as muscle fatty infiltrations (MFI) and fibrosis of the lumbar multifidus (LuM) muscles, thickness changes of the thoracolumbar fascia (TLF) and perimuscular connective tissues (PMCT) surrounding the abdominal lateral wall muscles. Rehabilitative ultrasound imaging (RUSI) parameters such as thickness and echogenicity are sensitive to this remodelling. This experimental laboratory study aimed to explore whether these RUSI parameters (LuM echogenicity and fascia thicknesses), hereafter called dependent variables (DV) were linked to independent variables (IV) such as (1) other RUSI parameters (trunk muscle thickness and activation) and (2) physical and psychological measures. RUSI measures, as well as a clinical examination comprising physical tests and psychological questionnaires, were collected from 70 participants with LBP. The following RUSI dependent variables (RUSI-DV), measures of passive tissues were performed bilaterally: (1) LuM echogenicity (MFI/fibrosis) at three vertebral levels (L3/L4, L4/L5 and L5/S1); (2) TLF posterior layer thickness, and (3) PMCT thickness of the fasciae between subcutaneous tissue thickness (STT) and external oblique (PMCT_STT/EO ), between external and internal oblique (PMCT_EO/IO ), between IO and transversus abdominis (PMCT_IO/TrA ) and between TrA and intra-abdominal content (PMCT_TrA/IA ). RUSI measures of trunk muscle's function (thickness and activation), also called measures of active muscle tissues, were considered as independent variables (RUSI-IV), along with physical tests related to lumbar stability (n = 6), motor control deficits (n = 7), trunk muscle endurance (n = 4), physical performance (n = 4), lumbar posture (n = 2), and range of motion (ROM) tests (n = 6). Psychosocial measures included pain catastrophizing, fear-avoidance beliefs, psychological distress, illness perceptions and concepts related to adherence to a home-based exercise programme (physical activity level, self-efficacy, social support, outcome expectations). Six multivariate regression models (forward stepwise selection) were generated, using RUSI-DV measures as dependent variables and RUSI-IV/physical/psychosocial measures as independent variables (predictors). The six multivariate models included three to five predictors, explaining 63% of total LuM echogenicity variance, between 41% and 46% of trunk superficial fasciae variance (TLF, PMCT_STT/EO ) and between 28% and 37% of deeper abdominal wall fasciae variance (PMCT_EO/IO , PMCT_IO/TrA and PMCT_TrA/IA ). These variables were from RUSI-IV (LuM thickness at rest, activation of IO and TrA), body composition (percent fat) and clinical physical examination (lumbar and pelvis flexion ROM, aberrant movements, passive and active straight-leg raise, loaded-reach test) from the biological domain, as well as from the lifestyle (physical activity level during sports), psychological (psychological distress-cognitive subscale, fear-avoidance beliefs during physical activities, self-efficacy to exercise) and social (family support to exercise) domains. Biological, psychological, social and lifestyle factors each accounted for substantial variance in RUSI-passive parameters. These findings are in keeping with a conceptual link between tissue remodelling and factors such as local and systemic inflammation. Possible explanations are discussed, in keeping with the hypothesis-generating nature of this study (exploratory). However, to impact clinical practice, further research is needed to determine if the most plausible predictors of trunk fasciae thickness and LuM fatty infiltrations have an effect on these parameters.

Mawangdui-Guidance Qigong Exercise for patients with chronic non-specific low back pain: Study protocol of a randomized controlled trial

Introduction

Worldwide, there is a high frequency of chronic non-specific low back pain (CNLBP), which is a significant public health concern. The etiology is complicated and diverse, and it includes a number of risk factors such as diminished stability and weak core muscles. Mawangdui-Guidance Qigong has been employed extensively to bolster the body in China for countless years. However, the effectiveness of treating CNLBP has not been assessed by a randomized controlled trial (RCT). In order to verify the results of the Mawangdui-Guidance Qigong Exercise and examine its biomechanical mechanism, we intend to perform a randomized controlled trial.

Methods and analysis

Over the course of 4 weeks, 84 individuals with CNLBP will be randomly assigned to receive either Mawangdui-Guidance Qigong Exercise, motor control exercise, or medication (celecoxib). Electromyographic data, including muscle activation time, iEMGs, root mean square value (RMS) and median frequency (MF), will be the main outcomes. The Japanese Orthopedic Association (JOA) Score, the Mcgill Pain Questionnaire (MPQ), beta-endorphin, and substance P are examples of secondary outcomes. At the start of treatment and 4 weeks later, all outcomes will be evaluated. SPSS version 20.0 (SPSS Inc., Chicago, IL, USA) will be used for all of the analysis.

Discussion

The prospective findings are anticipated to offer an alternative treatment for CNLBP and provide a possible explanation of the mechanism of Mawangdui-Guidance Qigong Exercise on CNLBP.

Ethics and dissemination

The Sichuan Regional Ethics Review Committee on Traditional Chinese Medicine has given the study approval (Approval No. 2020KL-067). It has also registered at the website of China Clinical Trial Center Registration. The application adheres to the Declaration of Helsinki’s tenets (Version Edinburgh 2000). Peer-reviewed papers will be used to publicize the trial’s findings.

Trial registration number

ClinicalTrials.gov, identifier ChiCTR2000041080.

A Comparative Electromyographic Analysis of Flying Squirrel and 3-Point Quadripod Exercise for Lumbar Multifidus Muscle Activations among Healthy Female Subjects

Physical therapists employ several exercises to alleviate low back pain (LBP). Electromyography (EMG) examination of exercises can monitor muscle activation to help clinicians determine the exercise’s effect on stabilisation, endurance, or strength. This study evaluated surface EMG activity comparison for Flying Squirrel Exercise (FSE) and the novel 3-Point Quadripod Exercise (3-PQE) to find the most effective exercise for stimulating the lumbar multifidus (LM) muscle. The study recruited 64 healthy young females (19–24 years). Raw data were normalized and are expressed as the percentage of maximum voluntary isometric contraction (%MVIC). The test–retest reliability of the EMG recordings was estimated using intraclass correlation coefficient (ICC3,1). One-way ANOVA was used to statistically analyse and compare the EMG amplitudes during the two exercises. The ICCs for 3-PQE and FSE were 0.94 (SEM, 21.7% MVIC) and 0.87 (SEM, 19.05% MVIC), respectively. The 3-PQE (69 ± 26% MVIC) demonstrated significantly higher activity than did FSE (30 ± 18% MVIC) (F = 15.573, p = 0.001). Thus, 3-PQE might be a feasible strategy for the prevention and rehabilitation of LBP in females.

The Role of Exercise in Treating Low Back Pain

ABSTRACT

The purpose of this review is to highlight the role of exercise in preventing and managing acute and chronic axial low back pain (LBP). LBP is one of the leading contributors to years lived with disability as well as health care expenditures in the United States. With an expected increase in prevalence due to an aging population, sports medicine providers have a unique opportunity to provide effective treatment strategies incorporating exercise advice and prescription. Although the majority of individuals with acute LBP will have their symptoms resolve spontaneously, almost 40% will have recurrence or develop chronic LBP within 1 year. No single exercise method has been shown to be more effective than another. The evidence for walking programs, aerobic exercise, yoga, Pilates, and tai chi for LBP is discussed. Our review summarizes the beneficial role of a personalized exercise program and related counseling strategies in the prevention and management of LBP.

Effects of arm and leg positions on lumbar multifidus muscle activity while on hands and knees or while standing

BACKGROUND

The lumbar multifidus (LMF) muscle, which is involved in the mechanical stability of the lumbar spine, reportedly undergoes atrophy in patients with low back pain. Preventing or mitigating low back pain requires strengthening the LMF muscle; however, methods for triggering selective and significant contraction of this muscle have not been fully studied. This study aims to clarify how, in the hands-and-knees or standing position, the position of the arm and leg on one side affects the activity of the lumbar erector spinae (LES) and LMF muscles.

METHODS

We recruited nine adult men with no prior history of low back pain. Measurements were taken in four different postures under varying conditions (that is, one arm and one leg were lifted in either the hands-and-knees or standing position,) as follows: (1) shoulder joint flexion and hip joint extension in the hands-and-knees position; (2) 90° shoulder joint abduction and hip joint abduction in the hands-and-knees position; (3) shoulder joint flexion and hip joint extension in the standing position; and (4) 90° shoulder joint abduction and hip joint abduction in the standing position. The 90° shoulder joint abduction involved simultaneous horizontal abduction, while the hip joint abduction involved simultaneous extension. Muscle activity of the LES and LMF in each posture was measured using a surface electromyograph.

RESULTS

Muscle activity of the LMF was significantly higher in 90° shoulder joint abduction and hip joint abduction than in shoulder joint flexion and hip joint extension in both the hands-and-knees and standing positions. The LES muscle showed no significant differences in activity between each posture.

CONCLUSIONS

The results suggest that unilateral 90° shoulder joint abduction and contralateral hip joint abduction in the hands-and-knees and standing positions may produce selective and significant contraction of the LMF muscle.

Electromyographic Analysis of Hip and Trunk Muscle Activity During Side Bridge Exercises in Subjects With Gluteus Medius Weakness

CONTEXT

Side bridge exercises strengthen the hip, trunk, and abdominal muscles and challenge the trunk muscles without the high lumbar compression associated with trunk extension or curls. Previous research using electromyography (EMG) reports that performance of the side bridge exercise highly activates the gluteus medius (Gmed). However, to the best of our knowledge, no previous research has investigated EMG amplitude in the hip and trunk muscles during side bridge exercise in subjects with Gmed weakness.

OBJECTIVE

The purpose of this study was to examine the EMG activity of the hip and trunk muscles during 3 variations of the side bridge exercise (side bridge, side bridge with knee flexion, and side bridge with knee flexion and hip abduction of the top leg) in subjects with Gmed weakness.

DESIGN

Repeated-measures experimental design.

SETTING

Research laboratory.

PATIENTS

Thirty subjects (15 females and 15 males) with Gmed weakness participated in this study.

INTERVENTION

Each subject performed 3 variations of the side bridge exercise in random order.

MAIN OUTCOME MEASURES

Surface EMG was used to measure the muscle activities of the rectus abdominis, external oblique, longissimus thoracis, multifidus, Gmed, gluteus maximus, and tensor fasciae latae (TFL), and Gmed/TFL muscle activity ratio during 3 variations of the side bridge exercise.

RESULTS

There were significant differences in Gmed (F2,56 = 110.054, P < .001), gluteus maximus (F2,56 = 36.416, P < .001), and TFL (F2,56 = 108.342, P < .001) muscles among the 3 side bridge exercises. There were significant differences in the Gmed/TFL muscle ratio (F2,56 = 20.738, P < .001).

CONCLUSION

Among 3 side bridge exercises, the side bridge with knee flexion may be effective for the individuals with Gmed weakness among 3 side bridge exercises to strengthen the gluteal muscles, considering the difficulty of the exercise and relative contribution of Gmed and TFL.

Muscle activation in pelvic anteversion and retroversion

Abstract Introduction: The inability to maintain good pelvic stability has been attributed to inefficient muscle coordination and deconditioning of the stabilizing muscles. Despite this, little is known about the role of the pelvic muscles in anteversion and retroversion movements. Objective: To compare the neuromuscular activity of the tensor fascia lata, gluteus medius, upper and lower portions of the gluteus maximus, and multifidus in pelvic anteversion and retroversion. Methods: The neuromuscular activity of 17 healthy young adults (aged 25.3 ± 4.6 years) was assessed during five repetitions of the pelvic anteversion and retroversion movements. The Vicon-Nexus system (10 cameras) was used for the kinematic analysis of the pelvis in the sagittal plane (anteversion and retroversion), and the TeleMyo DTS Desk Receiver electromyograph and the Myomuscle v. 3.8 software to measure neuromuscular activity. The paired samples t-test was used to compare muscle activity between pelvic anteversion and retroversion movements using the Statistica v.8 software with a significance level of p < 0.05. Results: The comparison of the movements showed greater muscle activity in the inferior gluteus maximus in retroversion and greater activity in the multifidus in pelvic anteversion. The upper portion of the gluteus maximus showed relevant activation in both movements. Conclusion: There was more pronounced activity of the lower portion of the gluteus maximus in retroversion, while the upper gluteus maximus showed relevant activation level in both movements. The multifidi were more active in retroversion.

Effect of Increased Lumbar Lordosis on Lumbar Multifidus and Longissimus Thoracis Activation During Quadruped Exercise in Patients With Chronic Low Back Pain: An EMG Study

The objective was to investigate the electromyographic activity of the lumbar multifidus (MF) muscle and longissimus thoracis muscle, along with their activity ratio (MF longissimus thoracis ratio), during quadruped stabilization exercise performed with neutral posture and with increased lumbar lordosis in patients with chronic low back pain (CLBP). A total of 23 patients with CLBP (12 females and 11 males) were recruited based on inclusion and exclusion criterion. Each patient performed 4 exercises in random order, with surface electromyography electrodes and an electrogoniometer attached. A cross-sectional study design was used to measure the amplitude of muscle activation (as a percentage of maximum voluntary contraction) in each patient across the 2 muscles (MF and longissimus thoracis) during quadruped stabilization exercise with neutral posture and with increased lumbar lordosis. A 2-way analysis of variance was conducted, which demonstrated a statistically significant increase in the recruitment of MF with increased lumbar lordosis in patients with CLBP during quadruped exercise. An increase of 9.7% and 16.9% maximum voluntary contraction in MF electromyographic activity was observed in lumbar lordosis posture during the quadruped leg raise and quadruped leg-arm raise exercise, respectively (P < .01), when compared to the neutral posture. The increased recruitment of MF with lumbar lordosis in the quadruped position has strong implications in the assessment and management of patients with CLBP.

One session of motor control exercise improves joint position sense assessed by an iPhone application: a randomized controlled trial

[Purpose] To establish the test-retest reliability of an iPhone application and determine the immediate effect of motor control exercise (MCE) on lumbar position sense. [Participants and Methods] This study used a two-arm, randomized controlled trial design with a blinded assessor. Sixty healthy participants were randomized into the exercise or control group. The exercise group underwent 30-min MCE, whereas the control group rested for 15 min. Lumbar motion measured by two iPhones with goniometer application was used to determine the test-retest reliability. Absolute repositioning errors (pre- and post-test) from the control and exercise groups were used to determine the immediate effect of MCE on lumbar position sense. [Results] The test-retest reliability was 0.67–0.95. A significant interaction effect was found for Angle*Time, main effect of Angle, and main effect of Time. Post-hoc comparison showed a significant improvement in position sense at 45° and 60° in the exercise group. [Conclusion] The findings suggest that a mobile phone application has the ability to detect changes in lumbar position sense between sessions that exceed measurement error following MCE. One session of specific MCE can improve lumbar position sense at high lumbar flexion.

Postural cueing increases multifidus activation during stabilization exercise in participants with chronic and recurrent low back pain: An electromyographic study

Persons with low back pain (LBP) have demonstrated altered morphology and function of the deep multifidus (DM). This study examined the effects of postural cueing for increased lumbar lordosis on DM and longissimus thoracis (LT) activation during lumbar stabilization exercises (LSE) performed by persons with LBP. Nine adults with a history of chronic or recurrent LBP were recruited. Fine-wire EMG data was collected while participants performed 10 LSE's in neutral posture and with postural cueing. Percent maximum voluntary isometric contraction of L5 DM and T12 LT, and ratios of activation (DM/LT) were analyzed. There was a significant main effect for posture on DM activation (p < 0.001), indicating greater activation levels during exercises performed with postural cueing vs. neutral posture. LT activation did not increase significantly with postural cueing. Following a significant 1-way repeated measures ANOVA (p = 0.034) for the postural cueing condition, pairwise comparisons demonstrated significantly higher DM/LT activation ratios for prone leg lift, variable-angle Roman chair at 15°, bridging, and bilateral arm and leg lift. These results suggest postural cueing can be used across a range of LSE intensities to increase DM activation without a significant increase in LT activation in patients with chronic or recurrent LBP.

From the international space station to the clinic: how prolonged unloading may disrupt lumbar spine stability

BACKGROUND CONTEXT

Prolonged microgravity exposure is associated with localized low back pain and an elevated risk of post-flight disc herniation. Although the mechanisms by which microgravity impairs the spine are unclear, they should be foundational for developing in-flight countermeasures for maintaining astronaut spine health. Because human spine anatomy has adapted to upright posture on Earth, observations of how spaceflight affects the spine should also provide new and potentially important information on spine biomechanics that benefit the general population.

PURPOSE

This study compares quantitative measures of lumbar spine anatomy, health, and biomechanics in astronauts before and after 6 months of microgravity exposure on board the International Space Station (ISS).

STUDY DESIGN

This is a prospective longitudinal study.

SAMPLE

Six astronaut crewmember volunteers from the National Aeronautics and Space Administration (NASA) with 6-month missions aboard the ISS comprised our study sample.

OUTCOME MEASURES

For multifidus and erector spinae at L3-L4, measures include cross-sectional area (CSA), functional cross-sectional area (FCSA), and FCSA/CSA. Other measures include supine lumbar lordosis (L1-S1), active (standing) and passive (lying) flexion-extension range of motion (FE ROM) for each lumbar disc segment, disc water content from T2-weighted intensity, Pfirrmann grade, vertebral end plate pathology, and subject-reported incidence of chronic low back pain or disc injuries at 1-year follow-up.

METHODS

3T magnetic resonance imaging and dynamic fluoroscopy of the lumbar spine were collected for each subject at two time points: approximately 30 days before launch (pre-flight) and 1 day following 6 months spaceflight on the ISS (post-flight). Outcome measures were compared between time points using paired t tests and regression analyses.

RESULTS

Supine lumbar lordosis decreased (flattened) by an average of 11% (p=.019). Active FE ROM decreased for the middle three lumbar discs (L2-L3: -22.1%, p=.049; L3-L4: -17.3%, p=.016; L4-L5: -30.3%, p=.004). By contrast, no significant passive FE ROM changes in these discs were observed (p>.05). Disc water content did not differ systematically from pre- to post-flight. Multifidus and erector spinae changed variably between subjects, with five of six subjects experiencing an average decrease 20% for FCSA and 8%-9% for CSA in both muscles. For all subjects, changes in multifidus FCSA strongly correlated with changes in lordosis (r²=0.86, p=.008) and active FE ROM at L4-L5 (r²=0.94, p=.007). Additionally, changes in multifidus FCSA/CSA correlated with changes in lordosis (r²=0.69, p=.03). Although multifidus-associated changes in lordosis and ROM were present among all subjects, only those with severe, pre-flight end plate irregularities (two of six subjects) had post-flight lumbar symptoms (including chronic low back pain or disc herniation).

CONCLUSIONS

We observed that multifidus atrophy, rather than intervertebral disc swelling, associated strongly with lumbar flattening and increased stiffness. Because these changes have been previously linked with detrimental spine biomechanics and pain in terrestrial populations, when combined with evidence of pre-flight vertebral end plate insufficiency, they may elevate injury risk for astronauts upon return to gravity loading. Our results also have implications for deconditioned spines on Earth. We anticipate that our results will inform new astronaut countermeasures that target the multifidus muscles, and research on the role of muscular stability in relation to chronic low back pain and disc injury.

Upper thoracic spine mobilization and mobility exercise versus upper cervical spine mobilization and stabilization exercise in individuals with forward head posture: a randomized clinical trial

Background

Although upper cervical and upper thoracic spine mobilization plus therapeutic exercises are common interventions for the management of forward head posture (FHP), no study has directly compared the effectiveness of cervical spine mobilization and stabilization exercise with that of thoracic spine mobilization and mobility exercise in individuals with FHP.

Methods

Thirty-two participants with FHP were randomized into the cervical group or the thoracic group. The treatment period was 4 weeks, with follow-up assessment at 4 and 6 weeks after the initial examination. Outcome measures including the craniovertebral angle (CVA), cervical range of motion, numeric pain rating scale (NPRS), pressure pain threshold, neck disability index (NDI), and global rating of change (GRC) were collected. Data were examined with a two-way repeated-measures analysis of variance (group × time).

Results

Participants in the thoracic group demonstrated significant improvements (p < .05) in CVA, cervical extension, NPRS, and NDI at the 6-week follow-up compared with those in the cervical group. In addition, 11 of 15 (68.8%) participants in the thoracic group compared with 8 of 16 participants (50%) in the cervical group showed a GRC score of +4 or higher at the 4-week follow-up.

Conclusions

The combination of upper thoracic spine mobilization and mobility exercise demonstrated better overall short-term outcomes in CVA (standing position), cervical extension, NPRS, NDI, and GRC compared with upper cervical spine mobilization and stabilization exercise in individuals with FHP.

Trial registration

KCT0002307, April 11, 2017 (retrospectively registered).