scholarly journals Effects of Different Sling Settings on Electromyographic Activities of Selected Trunk Muscles: A Preliminary Research

2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Xin Li ◽  
Howe Liu ◽  
Ke-yu Lin ◽  
Ping Miao ◽  
Bao-feng Zhang ◽  
...  
Keyword(s):  
Erector Spinae ◽  
Transversus Abdominis ◽  
Trunk Muscles ◽  
Emg Activity ◽  
Lumbar Region ◽  
Mean Power ◽  
Mean Power Frequency ◽  
Effective Measure ◽  
Significant Difference ◽  
Dominant Side

Introduction. The supine and prone sling exercise may facilitate activation of the local trunk muscles. Does the side-lying sling exercise activate trunk muscles more easily than the supine and prone training with sling settings? Clinical work has shown that the side-lying sling exercise could reduce pain in patients with unilateral low back pain (LBP), but the mechanism behind it is unclear. The fundamental purpose of this preliminary study was to examine the electromyography (EMG) characteristics of trunk muscles during different sling lumbar settings on sixteen healthy adults. Methods. Amplitude and mean power frequency (MPF) of EMG signals were recorded from the transversus abdominis (TA), rectus abdominis (RA), multifidus (MF), erector spinae (ES), gluteus maximus (Gmax), and gluteus medius (Gmed) muscles while the subjects performed the supine lumbar setting (SLS), prone lumbar setting (PLS), left side-lying lumbar setting (LSLS), and right side-lying lumbar setting (RSLS). Results. During SLS and PLS, TA and MF showed significantly higher activity than RA and ES on the same side, respectively. The EMG activities of ES, TA, MF, Gmax, and Gmed had significant differences between the different sides during LSLS and RSLS, and the dominant-side muscles showed higher activity than the other side. There was no significant difference in core trunk muscles between different sling lumbar settings—only that the SLS of the MF/ES ratio was significantly higher than LSLS and RSLS. Conclusions. Sling exercises can be an effective measure to enhance MF and TA EMG activity, and the side-lying position can increase dominant-side Gmax and Gmed activity. Side-lying sling training does not activate more core muscles than the supine and prone training. Supine and prone exercise should be preferred over SLT to stabilize the lumbar region because of its high local/global muscle ratio.

scholarly journals Intermittent short-arm centrifugation is a partially effective countermeasure against upright balance deterioration following 60-day head-down tilt bed rest

2021 ◽  
Author(s):  
Enrico De Martino ◽  
Sauro Emerick Salomoni ◽  
Paul W. Hodges ◽  
Julie Hides ◽  
Kirsty Lindsay ◽  
...  
Keyword(s):  
Bed Rest ◽  
Standing Balance ◽  
Erector Spinae ◽  
Transversus Abdominis ◽  
Trunk Muscles ◽  
Control Group ◽  
Protective Effects ◽  
Gravitational Unloading ◽  
Frequency Power ◽  
Sway Frequency

This study investigated whether artificial gravity (AG), induced by short-radius centrifugation, mitigated deterioration in standing balance and anticipatory postural adjustments (APAs) of trunk muscles following 60-day head-down tilt bed rest. Twenty-four participants were allocated to one of three groups: control group (N=8); 30 minutes continuous AG daily (N=8); intermittent 6x5 minutes AG daily (N=8). Before and immediately after bed rest, standing balance was assessed in four conditions: eyes open and closed on both stable and foam surfaces. Measures including sway path, root-mean-square, and peak sway velocity, sway area, sway frequency power, and sway density curve were extracted from the centre of pressure displacement. APAs were assessed during rapid arm movements using intramuscular or surface electromyography electrodes of the rectus abdominis, obliquus externus and internus abdominis, transversus abdominis, erector spinae at L1, L2, L3, and L4 vertebral levels, and deep lumbar multifidus muscles. The relative latency between the EMG onset of the deltoid and each of the trunk muscles was calculated. All three groups had poorer balance performance in most of the parameters (all P<0.05) and delayed APAs of the trunk muscles following bed rest (all P<0.05). Sway path and sway velocity were deteriorated, and sway frequency power was less in those who received intermittent AG than in the control group (all P<0.05), particularly in conditions with reduced proprioceptive feedback. These data highlight the potential of intermittent AG to mitigate deterioration of some aspects of postural control induced by gravitational unloading, but no protective effects on trunk muscle responses were observed.

Validation and comparison of trunk muscle activities in male participants during exercise using an innovative device and abdominal bracing maneuvers

2021 ◽  
pp. 1-8
Author(s):  
Yuki Kurokawa ◽  
Satoshi Kato ◽  
Satoru Demura ◽  
Kazuya Shinmura ◽  
Noriaki Yokogawa ◽  
...  
Keyword(s):  
Muscle Activity ◽  
Muscle Activation ◽  
Voluntary Contraction ◽  
Trunk Muscle ◽  
Erector Spinae ◽  
Trunk Muscles ◽  
Activity Levels ◽  
Significant Difference ◽  
External Oblique ◽  
Internal Oblique

BACKGROUND: Abdominal bracing is effective in strengthening the trunk muscles; however, assessing performance can be challenging. We created a device for performing abdominal trunk muscle exercises. The effectiveness of this device has not yet been evaluated or compared OBJECTIVE: We aimed to quantify muscle activity levels during exercise using our innovative device and to compare them with muscle activation during abdominal bracing maneuvers. METHODS: This study included 10 men who performed abdominal bracing exercises and exercises using our device. We measured surface electromyogram (EMG) activities of the rectus abdominis (RA), external oblique, internal oblique (IO), and erector spinae (ES) muscles in each of the exercises. The EMG data were normalized to those recorded during maximal voluntary contraction (%EMGmax). RESULTS: During the bracing exercise, the %EMGmax of IO was significantly higher than that of RA and ES (p< 0.05), whereas during the exercises using the device, the %EMGmax of IO was significantly higher than that of ES (p< 0.05). No significant difference was observed in the %EMGmax of any muscle between bracing exercises and the exercises using the device (p= 0.13–0.95). CONCLUSIONS: The use of our innovative device results in comparable activation to that observed during abdominal bracing.

scholarly journals Core Muscle Activity during Physical Fitness Exercises: A Systematic Review

2020 ◽  
Vol 17 (12) ◽  
pp. 4306 ◽  
Author(s):  
José M. Oliva-Lozano ◽  
José M. Muyor
Keyword(s):  
Systematic Review ◽  
Physical Fitness ◽  
Rectus Abdominis ◽  
Core Stability ◽  
Erector Spinae ◽  
Transversus Abdominis ◽  
Emg Activity ◽  
Electromyographic Activity ◽  
Lumbar Multifidus ◽  
External Oblique

The aim of this study was to systematically review the current literature on the electromyographic (EMG) activity of six core muscles (the rectus abdominis, the internal and external oblique, the transversus abdominis, the lumbar multifidus, and the erector spinae) during core physical fitness exercises in healthy adults. A systematic review of the literature was conducted on the Cochrane, EBSCO, PubMed, Scopus, and Web of Science electronic databases for studies from January 2012 to March 2020. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were used. The inclusion criteria were as follows: (a) the full text available in English; (b) a cross-sectional or longitudinal (experimental or cohorts) study design; (c) the reporting of electromyographic activity as a percentage of maximum voluntary contraction (% MVIC), millivolts or microvolts; (d) an analysis of the rectus abdominis (RA), transversus abdominis (TA), lumbar multifidus (MUL), erector spinae (ES), and the internal (IO) or external oblique (EO); (e) an analysis of physical fitness exercises for core training; and (f) healthy adult participants. The main findings indicate that the greatest activity of the RA, EO, and ES muscles was found in free-weight exercises. The greatest IO activity was observed in core stability exercises, while traditional exercises showed the greatest MUL activation. However, a lack of research regarding TA activation during core physical fitness exercises was revealed, in addition to a lack of consistency between the studies when applying methods to measure EMG activity.

scholarly journals Force–EMG Changes During Sustained Contractions of a Human Upper Airway Muscle

2009 ◽  
Vol 101 (2) ◽  
pp. 558-568 ◽  
Author(s):  
Kori Schmitt ◽  
Christiana DelloRusso ◽  
Ralph F. Fregosi
Keyword(s):  
Low Frequency ◽  
Upper Airway ◽  
Central Fatigue ◽  
Endurance Performance ◽  
Emg Activity ◽  
Mean Power ◽  
Mean Power Frequency ◽  
Task Failure ◽  
Dilator Muscle ◽  
Voluntary Contractions

Human upper airway and facial muscles support breathing, swallowing, speech, mastication, and facial expression, but their endurance performance in sustained contractions is poorly understood. The muscular fatigue typically associated with task failure during sustained contractions has both central and intramuscular causes, with the contribution of each believed to be task dependent. Previously we failed to show central fatigue in the nasal dilator muscles of subjects that performed intermittent maximal voluntary contractions (MVCs). Here we test the hypothesis that central mechanisms contribute to the fatigue of submaximal, sustained contractions in nasal dilator muscles. Nasal dilator muscle force and EMG activities were recorded in 11 subjects that performed submaximal contractions (20, 35, and 65% MVC) until force dropped to ≤90% of the target force for ≥3 s, which we defined as task failure. MVC and twitch forces (the latter obtained by applying supramaximal shocks to the facial nerve) were recorded before the trial and at several time points over the first 10 min of recovery. The time to task failure was inversely related to contraction intensity. MVC force was depressed by roughly 30% at task failure in all three trials, but recovered within 2 min. Twitch force fell by 30–44% depending on contraction intensity and remained depressed after 10 min of recovery, consistent with low-frequency fatigue. Average EMG activity increased with time, but never exceeded 75% of the maximal, pretrial level despite task failure. EMG mean power frequency declined by 20–25% in all trials, suggesting reduced action potential conduction velocity at task failure. In contrast, the maximal evoked potential did not change significantly in any of the tasks, indicating that the EMG deficit at task failure was due largely to mechanisms proximal to the neuromuscular junction. Additional experiments using the interpolated twitch technique suggest that subjects can produce about 92% of the maximal evocable force with this muscle, which is not a large enough deficit to explain the entire shortfall in the EMG at task failure. These data show that the nervous system fails to fully activate the nasal dilator muscles during sustained, submaximal contractions; putative mechanisms are discussed.

scholarly journals Changes in intra-abdominal pressure during postural and respiratory activation of the human diaphragm

2000 ◽  
Vol 89 (3) ◽  
pp. 967-976 ◽  
Author(s):  
Paul W. Hodges ◽  
Simon C. Gandevia
Keyword(s):  
Abdominal Cavity ◽  
Limb Movement ◽  
Erector Spinae ◽  
Transversus Abdominis ◽  
Trunk Muscles ◽  
Abdominal Pressure ◽  
Abdominal Muscles ◽  
Electromyographic Activity ◽  
Repetitive Movement ◽  
The Stability

In humans, when the stability of the trunk is challenged in a controlled manner by repetitive movement of a limb, activity of the diaphragm becomes tonic but is also modulated at the frequency of limb movement. In addition, the tonic activity is modulated by respiration. This study investigated the mechanical output of these components of diaphragm activity. Recordings were made of costal diaphragm, abdominal, and erector spinae muscle electromyographic activity; intra-abdominal, intrathoracic, and transdiaphragmatic pressures; and motion of the rib cage, abdomen, and arm. During limb movement the diaphragm and transversus abdominis were tonically active with added phasic modulation at the frequencies of both respiration and limb movement. Activity of the other trunk muscles was not modulated by respiration. Intra-abdominal pressure was increased during the period of limb movement in proportion to the reactive forces from the movement. These results show that coactivation of the diaphragm and abdominal muscles causes a sustained increase in intra-abdominal pressure, whereas inspiration and expiration are controlled by opposing activity of the diaphragm and abdominal muscles to vary the shape of the pressurized abdominal cavity.

scholarly journals Influence of Body Position on Shoulder and Trunk Muscle Activation During Resisted Isometric Shoulder External Rotation

2018 ◽  
Vol 10 (4) ◽  
pp. 355-360 ◽  
Author(s):  
David A. Krause ◽  
Lucas G. Dueffert ◽  
Jaclyn L. Postma ◽  
Eric T. Vogler ◽  
Amy J. Walsh ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Muscle Activation ◽  
External Rotation ◽  
Body Position ◽  
Trunk Muscle ◽  
Trunk Muscles ◽  
Emg Activity ◽  
Convenience Sample ◽  
Overhead Athletes ◽  
Significant Difference

Background: External rotation (ER) strengthening of the shoulder is an integral component of rehabilitative and preventative programs for overhead athletes. A variety of shoulder ER strengthening exercises are reported, including those intended to integrate the core musculature. The purpose of this study was to examine ER torque and electromyographic (EMG) activation of shoulder and trunk muscles while performing resisted isometric shoulder ER in 3 positions (standing, side lying, and side plank). Hypothesis: Significantly greater force and shoulder muscle activation would be generated while side lying given the inherent stability of the position, and greater trunk muscle activation would be generated in the less stable plank position. Study Design: Quasi-experimental repeated-measures study. Level of Evidence: Level 5. Methods: A convenience sample of 25 healthy overhead recreational athletes (9 men, 16 women) participated in this study. EMG electrodes were placed on the infraspinatus, posterior deltoid, middle trapezius, multifidi, internal obliques, and external obliques. EMG signals were normalized to a maximal isometric contraction. Participants performed resisted isometric ER in standing, side-lying, and side plank positions. Results were analyzed using a repeated-measures analysis of variance with post hoc Bonferroni corrections (α = 0.05). Results: There was no significant difference in ER torque between positions (α = 0.05). A significant difference in EMG activity of shoulder and trunk musculature between positions was found in 7 of the 8 muscles monitored. Significantly greater EMG activity in the infraspinatus, middle trapezius, and the nondominant external and internal obliques was found in the side plank position as compared with standing and side lying. Conclusion: While there was no difference in ER torque between the 3 exercise positions, EMG activity of the shoulder and trunk muscles was dependent on body position. Clinical Relevance: If a clinician is seeking to integrate trunk muscle activation while performing shoulder ER strengthening, the side plank position is preferred as compared with standing or side lying.

scholarly journals Activity of upper limb and trunk muscles during power walking

2015 ◽  
Vol 9 (2) ◽  
Author(s):  
Johann Peter Kuhtz-Buschbeck ◽  
Antonia Frendel
Keyword(s):  
Upper Limb ◽  
Muscle Activation ◽  
Erector Spinae ◽  
Trunk Muscles ◽  
Emg Activity ◽  
Normal Walking ◽  
Arm Swing ◽  
Temporal Muscle ◽  
Limb Muscles ◽  
Emg Patterns

<p>Background: Arm swing is deliberately emphasized during power walking, a popular aerobic fitness exercise. Electromyographic (EMG) activation curves of arm and shoulder muscles during power walking have not yet been examined. Aim: To describe the amount and pattern of EMG activity of upper limb muscles during power walking. Data are compared to normal walking and jogging. Method:  Twenty volunteers were examined on a treadmill at 6 km/h during (a) normal walking, (b) power walking, (c) jogging. EMG data were collected for the trapezius (TRAP), anterior (AD) and posterior deltoid (PD), biceps (BIC), triceps (TRI), latissimus dorsi (LD) and erector spinae (ES) muscles. Results:  Activity of four muscles (AD, BIC, PD, TRAP) was three- to fivefold stronger during power walking than normal walking. Smaller significant increases involved the TRI, LD and ES. Two muscles (AD, TRAP) were more active during power walking than running. Normal walking and power walking involved similar EMG patterns of PD, LD, ES, while EMG patterns of running and walking differed. Interpretation: Emphasizing arm swing during power walking triples the EMG activity of upper limb muscles, compared to normal walking. Similar basic temporal muscle activation patterns in both modes of walking indicate a common underlying motor program. </p>

scholarly journals Activity of upper limb and trunk muscles during power walking

2015 ◽  
Vol 9 (2) ◽  
Author(s):  
Johann Peter Kuhtz-Buschbeck ◽  
Antonia Frendel
Keyword(s):  
Upper Limb ◽  
Muscle Activation ◽  
Erector Spinae ◽  
Trunk Muscles ◽  
Emg Activity ◽  
Normal Walking ◽  
Arm Swing ◽  
Temporal Muscle ◽  
Limb Muscles ◽  
Emg Patterns

Background: Arm swing is deliberately emphasized during power walking, a popular aerobic fitness exercise. Electromyographic (EMG) activation curves of arm and shoulder muscles during power walking have not yet been examined. Aim: To describe the amount and pattern of EMG activity of upper limb muscles during power walking. Data are compared to normal walking and jogging. Method: Twenty volunteers were examined on a treadmill at 6 km/h during (a) normal walking, (b) power walking, (c) jogging. EMG data were collected for the trapezius (TRAP), anterior (AD) and posterior deltoid (PD), biceps (BIC), triceps (TRI), latissimus dorsi (LD) and erector spinae (ES) muscles. Results: Activity of four muscles (AD, BIC, PD, TRAP) was three- to fivefold stronger during power walking than normal walking. Smaller significant increases involved the TRI, LD and ES. Two muscles (AD, TRAP) were more active during power walking than running. Normal walking and power walking involved similar EMG patterns of PD, LD, ES, while EMG patterns of running and walking differed. Interpretation: Emphasizing arm swing during power walking triples the EMG activity of upper limb muscles, compared to normal walking. Similar basic temporal muscle activation patterns in both modes of walking indicate a common underlying motor program.

Electromyographic Activity of Trunk Muscles During Flexion-Distraction Treatment of Low Back Patients

1999 ◽  
Author(s):  
Maruti R. Gudavalli ◽  
Jerrilyn A. Backman ◽  
Steven J. Kirstukas ◽  
Anant V. Kadiyala ◽  
Avinash G. Patwardhan ◽  
...  
Keyword(s):  
Muscle Activity ◽  
Erector Spinae ◽  
Trunk Muscles ◽  
Emg Activity ◽  
Electromyographic Activity ◽  
Low Back ◽  
Mean Values ◽  
Flexion Extension ◽  
Left And Right ◽  
The Mean

Abstract The objective of this study was to determine the electromyographic (EMG) activity of the superficial muscles during the treatment of low back patients during a conservative procedure known as the Cox flexion-distraction procedure. A total of 33 low back pain patients were recruited for this study from chiropractic and allopathic orthopedic clinics. EMG signals were collected while the patient was in a prone relaxed position, during the treatment using the flexion-distraction procedure, and during maximum voluntary exertions in the three planes (flexion, extension, left and right lateral bending, and left and right twisting). The mean values of the Root Mean Square (RMS) values of EMG ratios during treatment versus resting indicate that the muscles are active during the treatment. This activity is more than the activity at rest. However the mean values of the RMS EMG ratios (during treatment versus maximum voluntary contraction) are small indicating that the muscle activity during treatment may not influence the treatment loads. The left and right muscles in all muscle groups were similarly active. During the treatment, erector spinae muscles were the most active, followed by the external oblique, and the rectus abdominus muscles. The results from this study provide quantitative data for the muscle activity during the flexion-distraction treatment. This information can be incorporated into computer models to estimate the loads generated during the flexion-distraction treatment due to the muscle activity compared to the loads generated by the chiropractic physician.

Aircraft Passenger Comfort Based on Muscle Activation and Perceived Discomfort During Long Flights

2020 ◽  
Vol 91 (5) ◽  
pp. 416-421
Author(s):  
Huining Pei ◽  
Suihuai Yu ◽  
Man Ding ◽  
Zhonghang Bai
Keyword(s):  
Muscle Activation ◽  
Upper Body ◽  
Mean Power ◽  
Mean Power Frequency ◽  
Passenger Comfort ◽  
Body Regions ◽  
Lower Back ◽  
Significant Difference ◽  
Power Frequency ◽  
Subjective Discomfort

OBJECTIVE: The purpose of this study was to investigate the comfort of aircraft passengers during long flights and to determine the effects of the seatback angle and the seat pitch on passengers’ upper body muscles (neck, shoulder, and lower back) and subjective comfort.METHODS: All subjects sat on an aircraft seat for 2 h with different levels of seatback angle and seat pitch. Subjective discomfort scores and root mean square (RMS) and mean power frequency (MPF) values were used to evaluate muscle fatigue, and all data were calculated for every 15-min interval.RESULTS: Significant increases of MPF for all three muscles were found at 30 min, along with significant increases in the perceived levels of discomfort (PLD) over 2 h. Besides, a 120° seatback angle and a 34˝ seat pitch resulted in lower PLD values for the lower back and hip areas than smaller ones (significant difference).DISCUSSION: It took around 30 min before pronounced discomfort in the upper body regions occurred during flight. The larger parameters of seatback angle and seat pitch may significantly contribute to the easing of subjective discomfort. Moreover, a decrease in MPF coupled with a concomitant increase in RMS does not appear to be a reliable indicator of discomfort rate. The need for further development of discomfort indicators which are more directly related to muscular activation is recognized.Pei H, Yu S, Ding M, Bai Z. Aircraft passenger comfort based on muscle activation and perceived discomfort during long flights. Aerosp Med Hum Perform. 2020; 91(5):416–421.

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