Left Lumbar Erector Spinae Research Articles

Study on diagnosis and treatment of lumbar disc herniation and related factors based on dynamic electromyography

To analyze dynamic electromyography characteristics and related factors of lumbar back muscle activity in patients with lumbar disc herniation, and to clarify the clinical significance of dynamic electromyography in the diagnosis and treatment of patients with lumbar disc herniation(LDH). From September 2014 to March 2021, 40 patients with lumbar disc herniation(LDH group) were detected by surface electromyography telemeter. There were 14 males and 26 females, aged from 20 to 61 years old, with an average of(40.68±10.56) years old, the course of illness was from 1 to 120 months, with an average of (17.75±27.56) months. In addition, 12 normal people were recruited as the control group. There were 2 males and 10 females. The age ranged from 24 to 53 years old, with an average of(36.50±10.30) years old. All subjects were subjected to dynamic electromyographic tests of the subthoracic erector spinae, lumbar erector spinae, and multifidus muscles during static standing and trunk flexion and extension. Compare the EMG activity data (average EMG amplitude, median frequency, original EMG graph) of the tested muscles between patients with lumbar disc herniation and normal people, and analyze the correlation between the general data of patients with lumbar disc herniation and the tested muscle EMG data. When standing still, the average electromyographic amplitude of the erector spinal muscle of the right and left thoracic segments of the subjects in the LDH group increased compared with the control group, and the difference was significant(P<0.05). In the trunk flexion and extension, the average electromyographic amplitude of the right and left proximal thoracic erector spinae, the right left lumbar erector spinae, and the right left multifidus muscle of the subjects in the LDH group are all larger than the control group, and the difference was significant(P<0.05). In the trunk flexion and extension, the median frequencies of the right left proximal thoracic erector spinae、the right left lumbar erector spinae, and the right left multifidus muscle of the subjects in the LDH group were all larger than the normal control group, and the difference was significant (P<0.05). During trunk flexion and extension, the original electromyographic patterns of subjects in the LDH group were significantly different from those in the control group. During the maintenance of the maximum trunk flexion of the subjects in the LDH group, there was a high level of electromyographic activity of the lower back muscles, and the electromyographic static signals that should appear regularly in the original signal could not be distinguished. When the trunk was flexed and extended, had gender, age, weight and height of subjects in the LDH group were not significantly correlated with the average EMG amplitude and median frequency of bilateral proximal thoracic, lumbar erector spinae and bilateral multifidus muscles respectively(P>0.05). Patients with lumbar disc herniation have characteristic surface EMG changes in the back muscles that are different from those of normal people. These features can more objectively reflect the patient's muscle condition and can be an effective indicator for the diagnosis and treatment effect evaluation of patients with lumbar disc herniation. It can be seen that surface electromyography is not only a detection method, it can be considered in the routine diagnosis and treatment plan of LDH to guide clinical work.

Oxygen Consumption (VO2) and Surface Electromyography (sEMG) during Moderate-Strength Training Exercises.

Oxygen consumption (VO2) during strength training can be predicted through surface electromyography (sEMG) of local muscles. This research aimed to determine relations between VO2 and sEMG of upper and lower body muscles to predict VO2 from sEMG during moderate-intensity strength training exercises. Of the 12 participants recruited, 11 were divided into two groups: untrained (n = 5; with no training experience) and trained (n = 6; with 2 months of training experience). On different days, each individual completed six training sessions. Each participant performed training sessions consisting of three types of dumbbell exercises: shoulder press, deadlift, and squat, while wearing a mask for indirect calorimetric measurements of VO2 using the Cortex Metalyzer 3B. sEMG measurements of the bilateral middle deltoid, lumbar erector spinae, quadriceps (rectus femoris), and hamstring (biceps femoris) muscles were recorded. The VO2 was predicted from sEMG root mean square (RMS) values of the investigated muscles during the exercise period using generalized estimating equation (GEE) modeling. The predicted models for the three types of exercises for the untrained vs. trained groups were shoulder press [QIC = 102, * p = 0.000 vs. QIC = 82, * p = 0.000], deadlift [QIC = 172, * p = 0.000 vs. QIC = 320, * p = 0.026], and squat [QIC = 76, * p = 0.000 vs. QIC = 348, * p = 0.001], respectively. It was observed that untrained vs. trained groups predicted GEE models [quasi-likelihood under an independence model criterion (QIC) = 368, p = 0.330 vs. QIC = 837, p = 0.058], respectively. The study obtained significant VO2 prediction models during shoulder press, deadlift, and squat exercises using the right and left middle deltoid, right and left lumbar erector spinae, left rectus femoris, and right and left biceps femoris sEMG RMS for the untrained and trained groups during moderate-intensity strength training exercises.

Effect of fatigue on muscle latency, muscle activation and perceived discomfort when exposed to whole-body vibration

Whole-body vibration and muscle fatigue have both been shown to delay the trunk muscle reflex response and increase trunk muscle activation, leading to an increased risk of low back injuries. However, the effects of whole-body vibration on previously fatigued trunk muscles have never been tested, despite studies showing that prolonged exposure to whole-body vibration can lead to muscle fatigue. The purpose of this research was to investigate the effects of muscle fatigue on muscle latency, muscle activation and perceived discomfort when exposed to whole-body vibration. The results showed that a fatigued muscle state resulted in increased muscle latency, muscle activation and perceived discomfort, which all escalate the risk of low back injuries. Additionally, the ISO 2631-1 comfort ratings did not increase with fatigue, showing a disconnect between these comfort ratings and the perceived discomfort ratings in a fatigued muscle state. Practitioner summary: When exposed to whole-body vibration, fatigued back muscles result in delayed muscle contraction, higher overall muscle activation and increased perceived discomfort, all of which are known to increase low back injury risk. ISO 2631-1 comfort ratings are unable to increase with fatigue, showing a disconnect with perceived discomfort ratings. Abbreviations: EMG: electromyography; EO: external oblique; IO: internal oblique; LE: lumbar erector spinae; LEO: left externaloblique; LIO: left internal oblique; LLE: left lumbar erector spinae; LTE: left thoracic erector spinae; MVC: maximum voluntarycontraction; REO: right external oblique; RIO: right internal oblique; RLE: right lumbar erector spinae; RTE: right thoracicerector spinae; SEAT: Seat Effective Amplitude Transmissibility; TE: thoracic erector spinae; WBV: whole body vibration

Effect of surgical radiation personal protective equipment on EMG-based measures of back and shoulder muscle fatigue: A laboratory study of novices

Interventional radiologists are at increased risk for musculoskeletal discomfort/disorders and this has been linked to the use of radiation personal protective equipment (rPPE). This study examined the effects of rPPE on the development of fatigue of the erector spinae and trapezius muscles. Surface electromyography (EMG) was used to capture muscle activity, and both time domain (average rectified value) and frequency domain (median frequency) measures were considered in the assessment of localized muscle fatigue. Sixteen participants performed a simulated surgical procedure requiring intermittent 30° flexed static trunk posture with and without rPPE on separate days. The results showed that the rPPE condition demonstrated significantly greater (p < 0.05) downward shift in median frequency in the left lumbar erector spinae and left lower thoracic erector spinae consistent with task-induced localized muscle fatigue. Ergonomic intervention strategies are discussed.

Effects of the trunk position on muscle stiffness that reflects elongation of the lumbar erector spinae and multifidus muscles: an ultrasonic shear wave elastography study.

The present study aimed to clarify the effects of the trunk position on muscle stiffness that reflects elongation of the lumbar erector spinae and lumbar multifidus muscles using ultrasonic shear wave elastography (SWE). The study included ten healthy men. The shear elastic modulus of the left lumbar erector spinae and lumbar multifidus muscles were evaluated using ultrasonic SWE. Measurement postures for the left lumbar erector spinae muscle were (1) prone position (Rest), (2) sitting position with the trunk flexed (Flexion), (3) the Flexion position adding right trunk lateral flexion (Flexion-Lateral Flexion), and (4) the Flexion position adding right trunk rotation (Flexion-Rotation 1). The left lumbar multifidus muscle were measured in positions (1)-(3), and (5) the Flexion position adding left trunk rotation (Flexion-Rotation 2). The shear elastic modulus of the lumbar erector spinae muscle in the Flexion-Lateral Flexion position was significantly higher than that in the Rest, Flexion, or Flexion-Rotation 1 positions. Shear elastic modulus of the lumbar multifidus muscle was similar in the Flexion, Flexion-Lateral Flexion, and Flexion-Rotation 2 positions, but significantly lower in the Rest position. The results of the present study suggest that the lumbar erector spinae muscle is stretched effectively in the position adding trunk contralateral lateral flexion to flexion. The results also indicate that the lumbar multifidus muscle, which does not appear to be affected by adding trunk contralateral lateral flexion or ipsilateral rotation to flexion, is stretched effectively in the trunk flexion position.

Evaluation of surgeon's muscle fatigue during thoracoscopic pulmonary lobectomy using interoperative surface electromyography.

The aim of this study was to document the physical stress experienced by a surgeon during thoracoscopic pulmonary lobectomy and mediastinal lymph node dissection for lung cancer by measuring the intraoperative electromyography (EMG). Surface EMG was recorded during 12 cases of thoracoscopic lobectomy. During the operation, 16 channels of a wireless EMG were used to measure muscle activity and fatigue from the bilateral muscles of the splenius capitis (SC), upper trapezius (UT), middle deltoid (MD), flexor carpi radialis (FCR), extensor carpi radialis (ECR), lumbar erector spinae (LES), rectus femoralis (RF), and tibialis anterior (TA). The EMG signals were processed to collect the values of the root mean square for muscle activity and median frequency (MF) for muscle fatigue. All operations were completed without adverse events. The mean operating time was 99.16±35.15 minutes. During the operation, the mean muscle activity of all muscles was 21.91±12.85 mV. High muscle activity was observed in the bilateral FCR and ECR, whereas low muscle activity was observed in the bilateral SC and LES. The final MFs in the bilateral SC and LES were found to be decreased from the initial status, which implied increased muscle fatigue. The muscles of the right and left LES were significantly fatigued by up to 29% and 37% compared to their initial status (P=0.021 and P=0.007, respectively). The MFs of the bilateral LES decreased with time (an average decreases of 0.008/5 minutes, P=0.002 in right LES and 0.004/5 minutes, P=0.018 in left LES). During thoracoscopic lobectomy, muscle fatigue was observed in muscles related to a static posture, such as the bilateral SC, UT, and ES. Further studies are required to investigate the ergonomic adjustments needed to reduce muscle fatigue in these static muscles.

Effect of abduction and external rotation of the hip joint on muscle onset time during prone hip extension with knee flexion.

[Purpose] This study investigated the effect of hip position on muscle onset time during prone hip extension with knee flexion. [Subjects] The study included 21 healthy male volunteers. [Methods] Muscle onset times of the right gluteus maximus, right hamstrings, bilateral lumbar erector spinae, and bilateral lumbar multifidus were measured using surface electromyography during right hip extension with knee flexion in the prone position. Measurements were made with the hip in 3 positions: (1) neutral, (2) abduction, and (3) abduction and external rotation. [Results] Gluteus maximus onset relative to the hamstrings was significantly earlier with hip abduction and with hip abduction and external rotation compared with that with the hip in the neutral position. Gluteus maximus onset relative to the hamstrings was significantly earlier with hip abduction and external rotation compared with that with hip abduction. The bilateral multifidus and left lumbar erector spinae onset times relative to the hamstrings were significantly earlier with hip abduction and external rotation compared with those with hip abduction and with the hip in the neutral position. [Conclusion] Abduction and external rotation of the hip during prone hip extension with knee flexion is effective for advancing the onset times of the gluteus maximus, bilateral multifidus, and contralateral lumbar erector spinae.

The association of low back pain, neuromuscular imbalance, and trunk extension strength in athletes

Imbalanced patterns of erector spinae activity and reduced trunk extension strength have been observed among patients with low back pain (LBP). The association between LBP and neuromuscular imbalance still remains unclear. To examine the relationship between LBP, neuromuscular imbalance, clinical symptoms, and trunk extension strength on two independent occasions, after dynamic neuromuscular changes through a back exercise program. Experimental longitudinal study of the lower back in a clinical setting. Eighty-two elite amateur tennis players with and without LBP. Clinical testing of spinal mobility and muscular flexibility of the lower back. Isometric voluntary maximum trunk extension strength. Surface electromyography (EMG) of lumbar erector spinae. Athletes underwent a standardized clinical examination with common tests for spinal mobility and muscular flexibility, followed by an isometric trunk extension tests in a specially built apparatus with simultaneous surface EMG recording from right and left lumbar erector spinae. Imbalance quotients were calculated using integrated EMG (IEMG) measures. The relationships between LBP, neuromuscular imbalance, trunk extension strength, and clinical findings were investigated before and after a back exercise program using univariate and multivariate logistic regression models. A significant association between neuromuscular imbalance of erector spinae and the occurrence of LBP was observed, whereas no significant imbalances were found in subjects without LBP. The number of subjects with LBP decreased proportionally with the occurrence of neuromuscular imbalance in the lumbar region after the completion of a back exercise program. However, neuromuscular imbalances were still present during retesting among subjects whose LBP did not resolve; the relationship between neuromuscular imbalance of lumbar erector spinae and LBP was significant again. On the contrary, no significant association between LBP and maximum isometric trunk extension strength or neuromuscular imbalance and maximum isometric trunk extension strength was found before or after the exercise program. No clear relationship between LBP and clinical testing of the lumbar spine or neuromuscular imbalance and clinical testing was found on the two independent testing occasions. A direct relationship between LBP and neuromuscular imbalance was documented in athletes with LBP. Maximum isometric trunk extension strength had no relationship to the presence of LBP or the occurrence of neuromuscular imbalance of erector spinae. Common clinical testing of spinal mobility and muscular flexibility had only limited correlation to LBP and neuromuscular imbalance.

A biomechanical comparison of lifting techniques between subjects with and without chronic low back pain during freestyle lifting and lowering tasks

Objective. To evaluate if chronic low back pain patients perform manual material handling tasks differently from control subjects. Design. Comparative study using a repeated measures design. Background. No study evaluated the lifting technique of back pain patients relative to control subjects during free style lifting and lowering tasks. Previous findings suggest that lowering would be more hazardous than lifting to the low back. It would be interesting to evaluate if chronic low back pain patients behave differently than controls when lifting and lowering. Methods. Thirty-three male subjects (18 controls, 15 suffering from non-specific chronic low back pain) participated. A 12-kg box was lifted (freestyle) from the floor to the hips (1) in front (symmetric task) or (2) to a shelf located at 90° on the right (asymmetric task) and was lowered back to the floor. A 3D biomechanical analysis involving the assessment of L5/S1 loading, posture of segments, inertial parameters, and EMG was performed. Results. There was no difference between the groups for postural (trunk and lower limb angles), inertial (trunk velocity and acceleration), and L5/S1 loading (moments and compression) variables. The patients showed abnormally low left lumbar erector spinae (symmetric task, lowering) or high left thoracic erector spinae (all tasks) EMG activation. Significant Group×Action (lifting vs lowering) interactions were also observed for some inertial and L5/S1 loading variables suggesting that the biomechanical differences detected between lifting and lowering may have a differential influence on the technique used by back pain patients and control subjects. Conclusions. The gross lifting technique of back pain patients was unaltered relative to controls but the activation of paraspinal muscles differed, suggesting that a more detailed biomechanical analysis, such as the use of EMG driven models, might be required to reveal lumbar impairments during lifting. Relevance To evaluate if chronic low back pain patients use naturally different lifting techniques to prevent pain exacerbation and damaged lumbar tissue overloading.