Cervical Erector Spinae Research Articles

Effect of Assistive Device for Neck Retraction (ANR) on Neck Muscles during Neck Retraction Exercise

[Purpose] The purpose of present study was to develop an exercise device for assisting neck retraction exercise and to investigate its effectiveness. [Subjects] Fifteen male subjects were recruited. [Methods] The subjects performed the neck retraction exercises with and without assistive device for neck retraction (ANR). EMG activities of the lower cervical erector spinae (LCE), and sternocleidomatoid (SCM) muscles were recorded. [Results] The ANR condition significantly increased LCE activation compared to the control condition. The ANR condition significantly decreased SCM activation compared to the control condition. [Conclusion] We suggest that the ANR condition will help the efficacy of the neck retraction exercise.

The Change of the Trunk Muscles Activation in the Adolescent Carrying a Backpack with Belts

Objective: The purpose of this study is to compare the EMG activities of the trunk muscles when carrying a backpack with belts and without belts. Background: This research aimed to explore the influence of carrying a backpack with belts on the trunk muscles activity and to suggest a desirable method of wearing backpacks. Method: Seventy five adolescents participated in this study. The EMG activities of upper trapezious, cervical erector spinae and rectus abdominis were collected. One way ANOVA was used to analyze the collected data. LSD was used for post-hoc test. Results: The EMG data from treadmill walking showed significant differences between carrying a backpack with belts and without belts for the cervical erector spinae and upper trapezious(p<.05) in all group(A Group: no belt, B Group: lumbar belt, C Group: lumbar-chest belt). In descending walking, significant difference were found for the cervical erector spinae and rectus abdominis in all group. In ascending walking, there were no significant differences in all group. LSD showed that the muscle activity of the trunk muscles decreased significantly when the lumbar belt and lumbar-chest belt were worn. Conclusion: The trunk muscles activities were decreased when the subjects were wearing a backpack with belts, comparing with wearing a backpack without belts. Application: These results can be used to provide useful information on how wearing a backpack in adolescent.

A comparative investigation of flexion relaxation phenomenon in healthy and chronic neck pain subjects

The cervical flexion relaxation phenomenon (FRP) is a neck extensor myoelectric "silence" that occurs during complete cervical and lumbar flexion. In contrast to low back pain, the changes that occur during FRP in chronic neck pain (CNP) patients are still not clear. The aim of this study was to assess the characteristics of this phenomenon in the cervical region in CNP patients and controls. Twenty-two women (23 ± 2.62 years) with chronic non-specific neck pain and 21 healthy women (23.4 ± 1.68 years) participated in this study. They accomplished a cervical flexion and extension from neutral position. Neck angle and surface electromyographic activity of cervical erector spinae (CES) and upper trapezius muscles were recorded. Appearance, onset and offset angle of the FRP were analysed and compared between the two groups. There were significant differences in the appearance of FRP between the two groups (P ≤ 0.001). The FRP in the CES muscles was observed in 85.7 % of healthy subjects and in 36.3 % of CNP patients, and no FRP was observed in the upper trapezius. Results of this study show that the onset and offset of FRP parameters were significantly different between the two groups (P ≤ 0.001). The results of the present study indicate that FRP in CNP patients was seen less than the healthy subjects, and moreover the FRP period was reduced in CNP patients. Our results also suggest that the changes in FRP of CNP patients may be due to the increased CES activity in these patients.

A comparison of surgeon's postural muscle activity during robotic-assisted and laparoscopic rectal surgery.

This study compared the muscular activity in the surgeon's neck and upper limbs during robotic-assisted laparoscopic (R-Lap) surgery and conventional laparoscopic (C-Lap) surgery. Two surgeons performed the same procedure of R-Lap and C-Lap low anterior resection, and real-time surface electromyography was recorded in bilateral cervical erector spinae, upper trapezius (UT) and anterior deltoid muscles for over 60min in each procedure. In one surgeon, forearm muscle activities were also recorded during robotic surgery. Similar levels of cervical muscle activity were demonstrated in both types of surgery. One surgeon showed much higher activity in the left UT muscle during robotic surgery. In the second surgeon, C-Lap was associated with much higher levels of muscle activity in both UT muscles. This may be related to the bilateral abducted arm posture required in maneuvering the laparoscopic instruments. In the forearm region, the "ulnaris" muscles for wrist flexion and extension bilaterally showed high amplitudes during robotic-assisted surgery. Robotic-assisted surgery seemed to demand a higher level of muscle work in the forearm region while greater efforts of shoulder muscles were involved during laparoscopic surgery. There are also individual variations in postural habits and motor control that can affect the muscle activation patterns. This study demonstrated a method of objectively examining the surgeon's physical workload during real-time surgery in the operating theatre, and further research should explore the surgeon's workload in a larger group of surgeons performing different surgical procedures.

Effects on cardiovascular response, perceived stress and cervical muscle activation during physical and mental conditions in computer users

PurposeOffice workers commonly suffer from work-related musculoskeletal disorders associated with intensive computer use, and both the physical and mental workload are important risk factors. This study used a typing task...

Effects on cardiovascular response, perceived stress and cervical muscle activation during physical and mental conditions in computer users

PurposeOffice workers commonly suffer from work-related musculoskeletal disorders associated with intensive computer use, and both the physical and mental workload are important risk factors. This study used a typing task...

An Investigation of Neck Muscle Activity in Asymptomatic Participants Who Show Different Lumbar Spine Motion Patterns During Prone Hip Extension

Objective The objective of the current study was to investigate whether any differences exist in the activity of the cervical erector spinae and upper trapezius (TRA) muscles between asymptomatic participants who show “normal” and “abnormal” lumbar spine motion patterns during the prone hip extension (PHE) test. Methods Twenty-six asymptomatic participants recruited from a chiropractic college participated in the study. Surface electromyography was used to record the activity of the cervical erector spinae and upper TRA muscles as each participant performed a set of 4 repetitions of PHE for each leg. An examiner observed the participant perform the movement and classified him/her as “positive” or “negative” based on the presence or absence (respectively) of 1 of 3 lumbar spine motion patterns. The mean activity levels of each muscle during the positive sets of PHE were compared with those during the negative sets. Results The mean activity of the upper TRA ipsilateral to the side of hip extension was significantly higher in the positive group compared with the negative group (difference, 13.3%; 95% confidence interval, 0.2%-24.4%; P = .0465). No other significant between-group differences were noted. Conclusion The results of this study indicate that the presence of abnormal lumbar spine motion patterns during the PHE test may be associated with altered cervicothoracic motor control strategies in asymptomatic individuals. Similar investigations using patients with neck pain are required to comment further on the generalizability and potential clinical importance of these findings.

Comparing Biofeedback With Active Exercise and Passive Treatment for the Management of Work-Related Neck and Shoulder Pain: A Randomized Controlled Trial

Ma C, Szeto GP, Yan T, Wu S, Lin C, Li L. Comparing biofeedback with active exercise and passive treatment for the management of work-related neck and shoulder pain: a randomized controlled trial. Objectives To compare the effects of biofeedback with those of active exercise and passive treatment in treating work-related neck and shoulder pain. Design A randomized controlled trial with 3 intervention groups and a control group. Setting Participants were recruited from outpatient physiotherapy clinics and a local hospital. Participants All participants reported consistent neck and shoulder pain related to computer use for more than 3 months in the past year and no severe trauma or serious pathology. A total of 72 potential participants were recruited initially, of whom a smaller group of individuals (n=60) completed the randomized controlled trial. Interventions The 3 interventions were applied for 6 weeks. In the biofeedback group, participants were instructed to use a biofeedback machine on the bilateral upper trapezius (UT) muscles daily while performing computer work. Participants in the exercise group performed a standardized exercise program daily on their own. In the passive treatment group, interferential therapy and hot packs were applied to the participants' necks and shoulders. The control group was given an education booklet on office ergonomics. Main Outcome Measures Pain (visual analog scale), neck disability index (NDI), and surface electromyography were assessed preintervention and postintervention. Pain and NDI were reassessed after 6 months. Results Postintervention, average pain and NDI scores were reduced significantly more in the biofeedback group than in the other 3 groups, and this was maintained at 6 months. Cervical erector spinae muscle activity showed significant reductions postintervention in the biofeedback group, and there were consistent trends of reductions in the UT muscle activity. Conclusions Six weeks of biofeedback training produced more favorable outcomes in reducing pain and improving muscle activation of neck muscles in patients with work-related neck and shoulder pain.

Effects of physical and mental task demands on cervical and upper limb muscle activity and physiological responses during computer tasks and recovery periods

The present study examined the effects of physical and mental workload during computer tasks on muscle activity and physiological measures. Activity in cervical postural muscles and distal forearm muscles, heart rate and blood pressure were compared among three tasks and rest periods of 15min each in an experimental study design. Fourteen healthy pain-free adults participated (7 males, mean age=23.2±3.0years) and the tasks were: (1) copy-typing ("typing"), (2) typing at progressively faster speed ("pacing"), (3) mental arithmetic plus fast typing ("subtraction"). Typing task was performed first, followed by the other two tasks in a random order. Median muscle activity (50th percentile) was examined in 5-min intervals during each task and each rest period, and statistically significant differences in the "time" factor (within task) and time×task factors was found in bilateral cervical erector spinae and upper trapezius muscles. In contrast, distal forearm muscle activity did not show any significant differences among three tasks. All muscles showed reduced activity to about the baseline level within first 5min of the rest periods. Heart rate and blood pressure showed significant differences during tasks compared to baseline, and diastolic pressure was significantly higher in the subtraction than pacing task. The results suggest that cervical postural muscles had higher reactivity than forearm muscles to high mental workload tasks, and cervical muscles were also more reactive to tasks with high physical demand compared to high mental workload. Heart rate and blood pressure seemed to respond similarly to high physical and mental workloads.

A field study on the work load and muscle fatigue at neck-shoulder in female sewing machine operators by using surface electromyography

To study neck and shoulder work-related muscle fatigue of female sewing machine operators. 18 health female sewing machine operators without musculoskeletal disorders work in Beijing garment industry factory as volunteers in participate of this study. The maximal voluntary contraction (MVC) and 20% MVC of bilateral upper trapezium and cervical erectors spinae was tested before sewing operations, then the whole 20 time windows (1 time window = 10 min) sewing machine operations was monitored and the surface electromyography (sEMG) signals simultaneously was recorded after monitoring the 20%MVC was tested. Use amplitude analysis method to reduction recorded EMG signals. During work, the median load for the left cervical erector spinae (LCES), right cervical erector spinae (RCES), left upper trapezium (LUT) and right upper trapezium (RUT) respectively was 6.78 ± 1.05, 6.94 ± 1.12, 5.68 ± 2.56 and 6.47 ± 3.22, work load of right is higher than the left; static load analysis indicated the value of RMS(20%MVC) before work was higher than that value after work, the increase of right CES and UT RMS(20%MVC) was more; the largest 20%MVE of bilateral CES occurred at 20th time window, and that of bilateral UT happened at 16th. The work load of female sewing machine operators is sustained "static" load, and work load of right neck-shoulder is higher than left, right neck-shoulder muscle is more fatigable and much serious once fatigued.

Relationship between Active Cervical Range of Motion and Flexion–Relaxation Ratio in Asymptomatic Computer Workers

A high prevalence and incidence of neck and shoulder pain is present in the working population, especially sedentary workers. Recent findings have indicated that the flexion-relaxation (FR) ratio in the cervical erector spinae (CES) muscles might be a significant criteria of neuromuscular impairment and function. Additionally, the active cervical range of motion (ROM) is frequently used for discriminating between individuals with pain and those who are asymptomatic. The purpose of the present study was to examine the relationship between the active cervical ROM and the FR ratio in a sample of regular visual display terminal (VDT) workers. In total, 20 asymptomatic male VDT workers were recruited. Active cervical ROM was measured by a cervical ROM (CROM) instrument. Surface electromyography (EMG) was used to collect myoelectrical signals from the CES muscles, and the FR ratio was calculated for statistical analysis. Pearson correlation coefficients were used to quantify the linear relationship between the active cervical ROM and the FR ratio. The values obtained for the FR ratio in the right CES muscles correlated significantly with the active cervical ROM measured in flexion (r=0.73, p<0.01), left lateral flexion (r=0.64, p<0.01), and left rotation (r=0.60, p<0.01). Flexion (r=0.74, p<0.01) and right lateral flexion (r=0.61, p<0.01) positively correlated with the left FR ratio. Extension and right rotation showed either a very weak or no correlation with the mean value of the right and left FR ratio. Our findings suggested that the cervical FR ratio had a positive correlation with cervical movements, and that changes of the activation patterns in CES demonstrated as cervical FR ratio are associated with reduction of the cervical range of motion including flexion and lateral flexion. In addition, muscular dysfunction of the CES could occur in regular computer workers prior to occurrence of pain; this means that the FR ratio could be used to evaluate the potential risk of neck discomfort in computer workers.

Surface electromyography signals from neck muscles during different craniocervical postures in a lateral recumbent position

Objective To survey cervical myoelectric signals during craniocervical flexion, neutral and extension postures, and to explore the evidence that proper head position can alleviate cervical muscle fatigue in a lateral recumbent position. Methods Surface electromyography (sEMG) signals were detected from the sternocleidomastoid, upper trapezius and erector spinae muscles of 30 young subjects bilaterally during craniocervical flexion,neutral and extension postures in the left lateral recumbent position. The integrated trace area (IEMG) and median frequency (MF) were estimated. Results The average IEMG of the sternocleidomastoid muscles was significantly lower in flexion than in extension bilaterally. The average IEMG of the erector spinae muscles was lower in extension than in flexion bilaterally, and the difference was again significant. The IEMGs of the upper trapezius muscle showed no significant difference on average in the three postures bilaterally. There was no significant MF difference in any of the muscles. Conclusions The muscles in the cervical back were less activated during craniocervical extension in a lateral recumbent position. A little cranicocervical extension is optimal while resting in a lateral recumbent position. Key words: Surface electromyography; Lateral recumbent position; Sternocleidomastoid muscle; Cervical erector spinae muscle; Upper trapezius muscle

A study of surgeons’ postural muscle activity during open, laparoscopic, and endovascular surgery

Different surgical procedures impose different physical demands on surgeons and high prevalence rates of neck and shoulder pain have been reported among general surgeons. Past research has examined electromyography in surgeons mainly during simulated conditions of laparoscopic and open surgery but not during real-time operations and not for long durations. The present study compares the neck-shoulder muscle activities in three types of surgery and between different surgeons. The relationships of postural muscle activities to musculoskeletal symptoms and personal factors also are examined. Twenty-five surgeons participated in the study (23 men). Surface electromyography (EMG) was recorded in the bilateral cervical erector spinae, upper trapezius, and anterior deltoid muscles during three types of surgical procedures: open, laparoscopic, and endovascular. In each procedure, EMG data were captured for 30 min to more than 1 h. The surgeons were asked to rate any musculoskeletal symptoms before and after surgery. The present study showed significantly higher muscle activities in the cervical erector spinae and upper trapezius muscles in open surgery compared with endovascular and laparoscopic procedures. Muscle activities were fairly similar between endovascular and laparoscopic surgery. The upper trapezius usually has an important role in stabilizing both the neck and upper limb posture, and this muscle also recorded higher activities in open compared with laparoscopic and endovascular surgeries. Surgeons reported similar degrees of musculoskeletal symptoms in open and laparoscopic surgeries, which were higher than endovascular surgery. The present study showed that open surgery imposed significantly greater physical demands on the neck muscles compared with endovascular and laparoscopic surgeries. This may be due to the lighter manual task demands of these minimally invasive surgeries compared with open procedures, which generally required more dynamic movements and more forceful exertions.

Active-Input Provides More Movement and Muscle Activity During Electronic Game Playing by Children

The majority of children in affluent countries now play electronic games, and this has lead to concerns about the health impact of this activity. Traditional electronic games have used gamepad, keyboard, and mouse input, but newer game interfaces that require more movement are now available. However the movement and muscle activity demands of electronic games have not been described. This study compared the amount of movement and muscle activity while 20 children aged 9 to 12 years watched a DVD and played games using handheld computer, gamepad, keyboard, steering wheel and, active-input (Webcam motion analysis–Sony EyeToy®) devices. Movement of the head, sacrum, foot, shoulder, wrist, and thumb was measured along with activity in cervical erector spinae, lumbar erector spinae, rectus femoris, upper trapezius, anterior deltoid, and wrist extensor muscles. Use of the wheel resulted in some increase in upper limb movement and muscle activity, but the other traditional input devices were usually as sedentary as watching a DVD. In contrast, use of the active-input device (EyeToy) resulted in substantial movement and muscle activity in limbs and torso. These results suggest that playing traditional electronic games is indeed a sedentary activity but that new active-input technologies may be useful in encouraging more movement and muscle activity in children.

The effects of a Pilates training program on arm–trunk posture and movement

Background Shoulder biomechanics and spine alignment have been found to be related to occasional and/or chronic neck–shoulder pain. Pilates is a physical training approach that focuses on posture, flexibility, segmental alignment and core control, through posture and movement exercises. The objectives of this study were to determine the effect of a Pilates training program on arm–trunk posture, strength, flexibility and biomechanical patterns during a functional shoulder flexion task. Methods Nineteen subjects (9 controls, 10 experimental) were assessed twice, 12 weeks apart, during which the experimental group was submitted to a Pilates training program (two 1-h sessions per week). The assessment consisted of trials of seated posture, abdominal strength, shoulder range of motion, and maximal shoulder flexion, during which neck, shoulder and trunk kinematics and the activity of 16 muscles were recorded. Findings After training, subjects showed smaller static thoracic kyphosis during quiet sitting and greater abdominal strength. The experimental group also showed reduced posterior and mediolateral scapular displacements, upper thoracic extension and lumbar lateral flexion, as well as higher activity of the ipsilateral cervical erector spinae, contralateral rhomboid muscles and lower activity of the ipsilateral lumbar erector spinae during the shoulder flexion task. Interpretation The Pilates training program was effective in improving abdominal strength and upper spine posture as well as in stabilizing core posture as shoulder flexion movements were performed. Since deficits in these functional aspects have previously been associated with symptoms in the neck–shoulder region, our results support the use of Pilates in the prevention of neck–shoulder disorders.

The influence of different sitting postures on head/neck posture and muscle activity

To date the influence that specific sitting posture has on the head/neck posture and cervico-thoracic muscle activity has been insufficiently investigated. Therefore the aim of this study was to investigate whether three different thoraco-lumbar sitting postures affect head/neck posture and cervico-thoracic muscle activity. Twenty (10 men, 10 women) asymptomatic subjects were placed in 3 standardized thoraco-lumbar sitting postures (lumbo-pelvic, thoracic upright and slump) to investigate their influence on cervico-thoracic muscle activity and head/neck posture. There were significant differences in lumbar and thoracic curvatures in the 3 different sitting postures ( P < 0.002). Slump sitting was associated with greater head/neck flexion, anterior translation of the head ( P < 0.001) and increased muscle activity of cervical erector spinae (CES) compared to thoracic and lumbo-pelvic sitting ( P = 0.001). Thoracic upright sitting showed increased muscle activity of thoracic erector spinae (TES) compared to slump and lumbo-pelvic postures ( P = 0.015). Upper trapezius (UT) demonstrated no significant difference in muscle activation in the 3 sitting postures ( P < 0.991). This study demonstrates that different sitting postures affect head/neck posture and cervico-thoracic muscle activity. It highlights the potential importance of thoraco-lumbar spine postural adjustment when training head/neck posture.

Examining the low, high and range measures of muscle activity amplitudes in symptomatic and asymptomatic computer users performing typing and mousing tasks

Past studies on work-related musculoskeletal disorders (WMSD) have reported increased median muscle activities in terms of 50th% of amplitude probability distribution function (APDF), and this was thought to be a manifestation of altered motor control--an important mechanism contributing to WMSD. The present study aimed to examine whether such altered motor control was also present in other parameters of APDF--the 10th and 90th% values, which can be considered indicators of the low and high measures of muscle activity. The difference between 10th and 90th% APDF can be considered an indicator of the variation in muscle activity amplitude (the "APDF range"). Surface electromyography was examined in female office workers as Case (n = 21) and Control (n = 18) subjects. The APDF variables were measured in cervical erector spinae (CES) and upper trapezius (UT) muscles during typing, mousing and type-and-mouse, for 20 min each. The Case Group had significantly higher CES activity in the 10th, 90th% and APDF range compared to Controls. The UT muscles showed similar trends but the between-group differences were not statistically significant. These results have demonstrated the robustness of the APDF variables as sensitive indicators of motor control variations in symptomatic subjects with musculoskeletal disorders.

During computing tasks symptomatic female office workers demonstrate a trend towards higher cervical postural muscle load than asymptomatic office workers: an experimental study

Do symptomatic female office workers perform computing tasks with higher cervical postural muscle loads (in terms of higher amplitudes and less muscular rest) and more discomfort compared with asymptomatic individuals? Are these differences in postural muscle loads consistent across bilateral (typing) and unilateral (mousing) conditions? an experimental case-control study. 18 symptomatic female office workers and 21 asymptomatic female office workers. Three conditions (typing, mousing, and type-and-mouse) were performed in random order. Muscle load was measured as median amplitude and gap frequency using surface EMG of bilateral cervical erector spinae and upper trapezius. Discomfort was measured using a numerical rating scale. The case group demonstrated 4.3% (95% CI 0.1 to 8.4) higher amplitude during typing and 3.5% (95% CI 0.1 to 6.9) higher amplitude during type-and-mouse in the right cervical erector spinae compared with the control group. There was a similar difference between groups in the left cervical erector spinae which also demonstrated a 1.2 gaps/min (95% CI -2.3 to 0.0) lower frequency during typing. The case group had significantly higher discomfort during all conditions compared with the control group. The case group demonstrated higher median amplitudes and lower gap frequencies than the control group during bilateral conditions (typing and type-and-mouse) compared with unilateral conditions (mousing) for both muscle groups. There was increased amplitude and decreased muscular rest in the cervical erector spinae of office workers performing typing and mousing tasks. These findings may represent a mechanism underlying computer-related musculoskeletal disorders.

A comparison of posture and muscle activity means and variation amongst young children, older children and young adults whilst working with computers

Children and young adults are the most frequent users of computers. Whilst guidelines for adults have been based on research, available guidelines for children have had to assume children and adults are similar due to limited research evidence derived specifically from children. This study aimed to compare the posture and muscle activity of children with young adults. Thirty six adults aged 18-25 years, 24 children aged 10-12 years and 18 children aged 5-6 years participated in a series of laboratory studies. Upper body postures were measured using a 3D motion analysis system. Muscle activity of bilateral cervical erector spinae and upper trapezius muscles was assessed. Mean and variation were examined, the latter using both amplitude range and Exposure Variation Analysis matrix standard deviation. Mean postures assumed by children tended to show more spinal flexion and spinal asymmetry than adults. However children also tended to show more variation in posture and muscle activity. These findings suggest that whilst there may be differences in how children and adults use computers, basic principles of encouraging appropriate postures and variation should apply for both children and adults.

Neck–shoulder muscle activity in general and task-specific resting postures of symptomatic computer users with chronic neck pain

Past research on work-related musculoskeletal disorders (WMSD) has frequently examined the activity of neck–shoulder muscles such as upper trapezius (UT) and cervical erector spinae (CES) during typing tasks. Increased electromyographic activity in these postural stabilising muscles has been consistently found in chronic neck pain patients under different physically stressful conditions. The present study compared muscle activity when female office workers with chronic neck pain ( n = 39) and asymptomatic controls ( n = 34) adopted two resting postures: (1) with hands on laps versus; and (2) hands on a keyboard. Resting hands on keyboard elicited significantly increased muscle activity in the right UT of subjects with high discomforts ( n = 22), similar to that observed during actual typing. In contrast, the asymptomatic controls showed no difference in muscle activity between the resting postures. This result suggested that altered muscle activation patterns were triggered by some anticipatory task demand associated with a task-specific position in some individuals.