EMG activities of the quadratus lumborum and erector spinae muscles during flexion-relaxation and other motor tasks

OBJECTIVE: The aim of this study was to provide new information on the myoelectrical activation of the quadratus lumborum, the deep lateral and the superficial medial lumbar erector spinae, the psoas, and the iliacus muscles in various motor tasks. DESIGN: An intramuscular electromyographic study was performed. BACKGROUND: The contribution of individual deep trunk muscles to the stability of the lumbar spine is relatively unknown in different tasks, including the flexion-relaxation phenomenon. METHODS: Seven healthy subjects participated. Fine-wire electrodes were inserted with a needle guided by ultrasound. RESULTS: The highest activity observed for quadratus lumborum and deep lateral erector spinae occurred in ipsilateral trunk flexion in a side-lying position and for superficial medial erector spinae during bilateral leg lift in a prone position. Quadratus lumborum and deep lateral erector spinae were activated when the flexion-relaxation phenomenon was present for superficial medial erector spinae, i.e. when its activity ceased in the latter part of full forward flexion of the trunk, held relaxed and kyphotic. CONCLUSIONS: In general, the activation of the investigated muscles showed a high degree of task specificity, where activation of a certain muscle was not always predictable from its anatomical arrangement and mechanical advantage.     

Myoglobin and enzyme adaptations in erector spinae muscles in thoracal scoliosis

Summary. Bilateral biopsies from the erector spinae muscles were taken during surgery from 10 females and two males (mean age 14, range 13–17 years) with thoracal scoliosis for 6 years (range 2–11 years). The biopsies were analysed for myoglobin (MYO), citrate synthase (CS) and creatine kinase MB (CK-MB). The severity of scioliosis was estimavoted by Cobb's angle, the greater the angle the more severe the disease. The convex/concave side ratio (CVX/CCV) was for CS l·3±0·4 (P<0·01), CK 0·9 ± 01 (P<0·05), CK-MB 1·6±0·4 (P<0·01) and for MYO 1·1±0·2 (P>0·05). No significant correlations were found between the CVX/CCV for CS, CK or CK-MB on the one hand and the Cobb's angle on the other. The CVX/CCV for MYO was, however, directly related to the angle (r= 0·80, P<0·01). For the lower range of angles (≤59°) the CVX/CCV for MYO was below unity (0·88, P>0·05) and for the larger angles (>59°) above unity (1·23, P<0·05). In conclusion, a dissociation in the adaptive response of m. erector spinae in scoliosis between mitochondrial enzyme and myoglobin content was demonstrated.     

Effects of myofascial release on flexibility and electromyographic activity of the lumbar erector spinae muscles in healthy individuals

ObjectiveTo investigate the effects of myofascial release on the flexibility and electromyographic activity of the lumbar erector spinae muscle in healthy individuals.MethodsTen healthy subjects were recruited to an intervention protocol of myofascial release techniques: (1) superficial myofascial release; (2) deep myofascial release apply along 10 sessions, twice a week, with 40 min per sessions. The outcomes evaluated were flexibility (Toe-Touch Test) and electromyography activity (EMG) of the lumbar erector spinae muscle (Iliocostalis and Longissimus bilaterally) during the movement of extension-flexion of the trunk. Paired t-test was used to compare the electromyographic outcomes, while the Wilcoxon test was used to compare the flexibility outcomes.ResultsThe myofascial release techniques increased the flexibility (p = 0.005; r = 0.88) and have no influence over the electromyographic activity of the right iliocostalis (p = 0.179; r = 0.43), right longissimus (p = 0.877; r = 0.05), left iliocostalis (p = 0.386; r = 0.29) and left longissimus (p = 0.418; r = 0.27).ConclusionsThe application of myofascial release techniques increase flexibility and did not influence over the electromyographic activity of the lumbar erector spinae muscles in healthy individuals. Further studies should include a larger sample with a sham group and/or compare EMG activity of the lumbar erector spinae muscles with patients with low back pain during the movement of extension-flexion of the trunk.     

Relationship between the thickness and hemodynamics of the erector spinae muscles in various lumbar curvatures

BACKGROUND: There is little information about the relationship between the changes of hemodynamics and the morphologic changes of the erector spinae muscle. METHODS: Fifty healthy male volunteers participated. Ultrasonography was used to measure muscle thickness, and near-infrared spectroscopy was used to measure tissue blood volume and its oxygenation in the erector spinae muscle at L3 in six different relaxed trunk postures (flexed 20 degrees , flexed 40 degrees, flexed maximum, neutral posture, extended 20 degrees, and extended maximum of the lumbar spine). We also evaluated the reproducibility of the near-infrared spectroscopy measurements. FINDINGS: Near-infrared spectroscopy gave highly reproducible measurements. The thickness of the erector spinae muscle and the total and oxygenated hemoglobin were simultaneously increased during relaxed extension and decreased during relaxed flexion. Changes in the thickness of the erector spinae muscle with various lumbar curvature were similar in pattern to the changes in tissue blood volume and its oxygenation. INTERPRETATION: The erector spinae muscles' thickness, tissue blood volume, and its oxygenation are simultaneously increased during relaxed extension and decreased during relaxed flexion, as demonstrated by non-invasive near-infrared spectroscopy and ultrasonography. These findings might afford a better understanding of the pathomechanics of posture-related back symptoms. RELEVANCE: The erector spinae muscles' thickness, tissue blood volume, and its oxygenation are simultaneously increased during relaxed extension and decreased during relaxed flexion, as shown by non-invasive near-infrared spectroscopy and ultrasonography. Changes in hemodynamics and morphology of the erector spinae muscles in asymptomatic subjects are given for further research on the pathomechanism of back pain.     

Effects of abdominal drawing-in during prone hip extension on the muscle activities of the hamstring,gluteus maximus,and lumbar erector spinae in subjects with lumbar hyperlordosis

[Purpose] The purpose of this study was to compare the effects of an abdominal drawing-in maneuver (ADIM), measured using a pressure bio-feedback unit, on the activities of the hamstring, gluteus maximus, and erector spinae muscles during prone hip extension. [Subjects and Methods] Thirty healthy adult subjects (14 male, 16 female), were recruited. Subjects’ lumbar lordosis and pelvic tilt angles were measured, and based on the results, the subjects were divided into two groups: a hyperlordotic lumbar angle (HLLA) group (n=15) and a normal lordotic lumbar angle (NLLA) group (n=15). The muscle activities of the hamstring and gluteus maximus, and of the erector spinae on the right side of the body, were recorded using surface electromyography. [Results] When performing ADIM with prone hip extension, the muscle activity of the gluteus maximus of the HLLA group significantly improved compared with that the NLLA group. [Conclusion] This study demonstrated that ADIM with prone hip extension was more effective at eliciting gluteus maximus activity in the HLLA group than in the NLLA group. Therefore, ADIM with prone hip extension may be useful for increasing the gluteus maximus activity of individuals with lumbar hyperlordosis.Key words: Abdominal drawing-in maneuver, Hyperlordotic lumbar angle, Prone hip extension     

Examination of the flexion relaxation phenomenon in erector spinae muscles during short duration slumped sitting

OBJECTIVE: The purpose of this study was to examine the myoelectric activity of the erector spinae muscles of the back in order to determine if the flexion relaxation phenomenon occurs in seated forward flexion or slumped postures. BACKGROUND: The flexion relaxation phenomenon during standing forward flexion is well documented. However, flexion relaxation in seated forward flexion has not been studied. It is possible that flexion relaxation could be linked with low back pain that some individuals experience during seated work. METHODS: Twenty-two healthy subjects (11 males, 11 females) participated in the study. Surface electromyography was used to measure the level of muscle activity at the thoracic and lumbar levels of the erector spinae muscles. An electromagnetic tracking device measured the three-dimensional movement of the lumbar spine. Five trials each of standing and seated forward flexion were performed. RESULTS: A slumped sitting posture yielded flexion relaxation of the thoracic erector spinae muscles, whereas the lumbar erector spinae muscle group remained at relatively constant activation levels regardless of seated posture. Thoracic erector spinae silence occurred at a smaller angle of lumbar flexion during sitting than the flexion relaxation angle observed during standing flexion relaxation. CONCLUSIONS: Since the myoelectric activity of the lumbar erector spinae did not increase, it is likely that the passive tissues of the vertebral column were loaded to support the moment at L4/L5. Ligaments contain a large number of free nerve endings which act as pain receptors and therefore could be a potential source of low back pain during seated work. RELEVANCE: Examination of flexion relaxation during seated postures may provide insight into the association between low back pain and seated work.     

Intramuscular hemodynamics in bilateral erector spinae muscles in symmetrical and asymmetrical postures with and without loading

BACKGROUND: Although attention has been paid to the relationship between the changes in blood circulation in erector spinae muscles and back pain, little is known about their hemodynamics in several various comparable postures with and without loading. Studies on hemodynamics of erector spinae muscles using near-infrared spectroscopy have been performed on subjects and patients mainly in forward flexion positions. METHODS: Two near-infrared spectroscopes were used to measure oxygenated hemoglobin, deoxygenated hemoglobin, and total hemoglobin in bilateral erector spinae muscles at L2-3 in subjects in 9 postures, and holding no load, 10 kg or 20 kg in maximum flexed and lateral bending. Those three values in each posture and loading condition were expressed as a percentage of their corresponding values obtained in the standing upright position, and designated and statistically analyzed as %Oxy-Hb, %Deoxy-Hb and %Total-Hb, respectively. FINDINGS: %Total-Hb and %Oxy-Hb in maximum flexion were the most decreased. In maximum lateral bending, %Oxy-Hb only in the contralateral erector spinae muscles was decreased. When the load was 20 kg, the decreases in %Oxy-Hb were the largest in maximum flexion and lateral bendings. INTERPRETATION: Using two near-infrared spectroscopes allowed us to measure simultaneously the hemodynamics of bilateral muscles. They demonstrated different responses in each side. Asymmetrical posture and loading were accompanied by asymmetrical changes of the bilateral erector spinae muscles. Stretched muscle had less blood volume and oxygenation, both of which decreased with increasing load. These results showed that these postures and conditions might lead to fatigue of the ES muscles.     

Effects of low-frequency electrical stimulation on cumulative fatigue and muscle tone of the erector spinae

[Purpose] The aim of this study was to determine the effect of low-frequency electrical stimulation on fatigue recovery of the erector spinae with cumulative fatigue induced by repeated lifting and lowering work. [Subjects] Thirty-two healthy men volunteered to participate in this study and they were randomly divided into three groups: a MC group of 12 persons who underwent microcurrent, a TENS group of 10 persons who underwent Transcutaneous electrical nerve stimulation, and a control group of 10 persons who only rested. [Methods] Cumulative fatigue was induced and then, EMG, muscle tone, CK and LDH serum levels of the erector spinae were measured. Each group then underwent the assigned intervention and was re-measured. To analyze the differences in fatigue between before and after the intervention, the paired t-test was conducted, while groups were compared using analysis of covariance with a control group. [Results] The MC groups showed a significant reduction in muscle fatigue and decreased muscle tone when compared to the control group. However, no significant differences were found between the TENS and control groups. [Conclusion] These results suggest that microcurrent stimulation was effective for recovery from cumulative muscle fatigue while TENS had no effect.Key words: Fatigue, Microcurrent, Transcutaneous electrical nerve stimulation     

超声引导下竖脊肌平面阻滞在围术期镇痛中的研究进展

超声引导下竖脊肌平面阻滞(ESPB)是一种新型的躯干神经阻滞技术,其结合了超声可视化技术的优点,能实时显示针尖的穿刺路径,准确地将局麻药注射到竖脊肌深面,从而有效阻滞竖脊肌平面及周围神经,获得良好的镇痛效果.ESPB不仅可以减少围术期阿片类药物的用量,而且为开放性手术提供了良好的术后镇痛效果.本文对ESPB的解剖基础、...     

Effects of integrating hip movements into bridge exercises on electromyographic activities of selected trunk muscles in healthy individuals

This study aimed to identify the electromyographic (EMG) effects in selected trunk muscles after incorporating hip movement into bridging exercise. Twenty-six healthy adults (13 men and 13 women) volunteered for this experiment. EMG data (% maximum voluntary isometric contraction) were recorded from the rectus abdominis (RA), obliquus internus (OI), erector spinae (ES), and multifidus (MF) muscles of the dominant side while the subjects performed 3 types of bridging exercise, including bridging alone (Bridging 1), bridging with unilateral hip movements (Bridging 2), and bridging with bilateral hip movements (Bridging 3) in a sling suspension system. The RA and OI showed greater EMG activity during Bridging 2 and 3 compared to Bridging 1, with the greatest OI activity during Bridging 3 (p < 0.05), and the activity of the MF appeared to be greater during Bridging 3 than during Bridging 1 and 2 (p < 0.05). Furthermore, the OI/RA and MF/ES ratios were significantly higher for Bridging 2 (OI/RA = 1.89 ± 1.41; MF/ES = 1.03 ± 0.19) and Bridging 3 (OI/RA = 2.34 ± 1.86; MF/ES = 1.03 ± 0.15) than Bridging 1 (IO/RA = 1.35 ± 0.92; MF/ES = 0.98 ± 0.16). The OI/RA ratio was significantly higher for Bridging 3 than for Bridging 2. Based on these results, adding hip abduction and adduction, particularly bilateral movements, could be a useful method to enhance OI and MF EMG activity and their activities relative to global muscles during bridging exercise.     

不同腹内压水平对腹腔间隔室综合征患者预后的影响

目的:探讨不同腹内压(IAP)水平对腹腔间隔室综合征(ACS)患者临床预后的影响.方法:通过检索Cochrane、Embase、Medline临床试验数据库、CNKI和CBM等文献数据库,收集国内外不同IAP水平ACS患者的随机对照实验(RCT),提取资料并评估方法学质量.结果:共纳入9个RCT,756例ACS患者,高IAP组病死率为21.63%,低IAP组病死率为6.18%,两组比较差异有统计学意义(P<0.01).结论:降低IAP可以降低ACS患者病死率.     

腹腔内压力监测与腹腔内积血量相关性的探讨

[目的]探讨腹腔内压力与腹腔积血量的关系.[方法]通过膀胱内压力测定间接了解腹部闭合性损伤病人手术前的腹腔内压力,在手术过程中测定腹腔内积血量,并采用直线回归分析腹腔内压力与腹腔积血量的关系.[结果]腹腔内压力与腹腔积血量呈直线正相关.[结论]通过腹腔内压力的测定可以粗略推断腹腔内积血量,便于病情评估.     

Lumbar posture biomechanics and its influence on the functional anatomy of the erector spinae and multifidus

Abstract

Background:

Lumbar posture has a significant impact on the functional biomechanics of the erector spinae and multifidus muscles, which has implications for the loads placed on the tissues of the lumbar spine.

Objectives:

The objective of this review is to discuss the effects of lumbar posture on the functional biomechanics of the different divisions of the erector spinae and the multifidus muscle and its importance when developing clinical interventions.

Methods:

This review used the search engines PubMed, EBSCO, CINAHL and SCOPUS to identify studies investigating erector spinae and multifidus muscle architecture and the influence of lumbar posture on the biomechanical properties of these muscles and the resulting impact on spinal loading.

Results:

Changes in lumbar curvature alter muscle fascicle obliquity, lever arm distances, the length–tension relationships and muscle volume of the different divisions of erector spinae and multifidus, which impact on the spine's ability to resist moments and shear forces.

Conclusion:

Changes in lumbar posture influence the functional biomechanics of the different divisions of erector spinae and the multifidus muscles. Therapists should develop low back interventions that avoid end range of lumbar postures and optimise the functional biomechanics of the erector spinae and multifidus muscles and minimise loading on the lumbar spine.     

Fatigue of abdominal and paraspinal muscles during sustained loading of the trunk in the coronal plane

OBJECTIVE: To measure fatigue-related changes in the electromyographic signals of trunk muscles during lateral bend loading, and to determine the effects of load magnitude, gender, and contraction time on these changes. DESIGN: A factorial experimental design. SETTING: A research laboratory. PARTICIPANTS: Twenty-four healthy volunteers (12 men, 12 women; mean age +/- SD, 22.9 +/- 3.1 yrs). INTERVENTION: Subjects sustained lateral bend loads at 20%, 40%, and 60% of their maximal exertion. OUTCOME MEASURES: Median frequency and total power of the power spectrum of the electromyographic signals. RESULTS: Trunk muscles' median frequency signals decreased and their total power increased as contraction time increased. These changes became more pronounced as the magnitude of loading increased. Men and women showed a similar rate of median frequency decline, but the total power of signals in men was larger than that in women. All muscles showed signs of fatigue, except that at 20% of maximal exertion only thoracic erector spinae fatigued significantly. CONCLUSIONS: Endurance training of paraspinal and abdominal muscles may be useful in preventing low back pain associated with lateral bend loading. The risk of back pain is similar in both genders and is higher with larger load magnitude and longer contraction time.     

The effects of repetitive motion on lumbar flexion and erector spinae muscle activity in rowers

OBJECTIVE: The purpose of this study was to investigate changes in lumbar flexion together with the pattern and level of muscle activity of selected erector spinae during a rowing trial.Design. Cross-sectional repeated measures design. BACKGROUND: Low back pain is a common problem in rowers. The amount of lumbar flexion occurring during rowing might influence the possibility of injury. METHODS: Sixteen young adult school rowers participated in the study. Changes in lumbar flexion and muscle activity were recorded across the drive phase, at three stages of an ergometer based rowing trial. Lumbar flexion was calculated by computerised motion analysis of surface markers attached to the spinous processes of L1 and S1. Surface electromyography techniques were used to examine the magnitude of activity from three erector spinae muscles. The median frequency of the electromyographic signal was examined to quantify fatigue in the erector spinae muscles during isometric maximal effort muscle activation prior to and after the rowing trial. RESULTS: Lumbar flexion increased significantly (P<0.05) during the rowing trial, as did the magnitude of electromyographic activity from sites over the lumbar multifidus, iliocostalis lumborum and longissimus thoracis muscles. The median frequency decreased significantly (P<0.05) in each muscle examined. CONCLUSIONS: The findings showed that rowers attain relatively high levels of lumbar flexion during the rowing stroke, and these levels are increased during the course of the rowing trial. Indirect evidence of muscle fatigue in erector spinae muscles was also apparent, and this observation may in part be responsible for the increased levels of lumbar flexion observed. RELEVANCE: Excessive lumbar flexion may influence the potential for injury to spinal structures. An awareness of increased lumbar flexion and muscle fatigue in the erector spinae muscles may be important for injury prevention programs for rowers.