Activation of Scapular and Lumbopelvic Muscles During Core Exercises Executed on a Whole-Body Wobble Board

2019 ◽  
Vol 28 (6) ◽  
pp. 623-634 ◽  
Author(s):  
Andrea Biscarini ◽  
Samuele Contemori ◽  
Giuditta Grolla

Context: Previous studies highlighted that exercises executed on unstable surfaces can yield important benefits to the function of the core musculature in rehabilitation settings, general conditioning settings, and athletic training when properly introduced within a periodized training schedule. No previous study has analyzed core-stability exercises executed in lying, quadruped, plank, and bridge positions on a whole-body wobble board (WWB) specifically designed to accommodate the exerciser’s entire body and promote whole-body instability. We have designed a WWB allowed to roll in a plane perpendicular to its longitudinal axis to promote proactive and reactive activation of the core muscles with a transverse or diagonal line of action, which provides trunk and pelvic stability with low spine compression forces. Purpose: To determine the effect of the use of this newly designed WWB by assessing differences in core-muscle activity during core-stability exercises performed on the ground, in a stable condition, and on the WWB. Design: Controlled laboratory study. Setting: Research laboratory. Patients or Other Participants: Eighteen participants recruited from fitness centers. Intervention(s): The electromyographic (EMG) activity of lumbopelvic and scapular muscles has been recorded during core-stability exercises executed on the WWB (unstable condition) and on ground (stable condition). Main Outcome Measure(s): Mean and peak EMG activity were compared between stable and unstable condition with paired t tests or Wilcoxon signed-rank tests. Results: Overall, exercises performed on the WWB yielded significantly higher EMG activity in the serratus anterior and anterolateral abdominal muscles compared with the same exercises executed on the ground. Conversely, for the bird dog exercise, lower-back muscle activity was significantly higher on the ground. Conclusions: Compared with the ground, core-stability exercises executed on WWB constitute a simple and effective strategy to increase the activity level of the core muscles that control transverse-plane lumbopelvic and trunk stability, avoiding the use of external overload.

2002 ◽  
Vol 88 (3) ◽  
pp. 1177-1184 ◽  
Author(s):  
R. H. Westgaard ◽  
P. Bonato ◽  
K. A. Holte

The surface electromyographic (EMG) signal from right and left trapezius muscles and the heart rate were recorded over 24 h in 27 healthy female subjects. The root-mean-square (RMS) value of the surface EMG signals and the heartbeat interval time series were calculated with a time resolution of 0.2 s. The EMG activity during sleep showed long periods with stable mean amplitude, modulated by rhythmic components in the frequency range 0.05–0.2 Hz. The ratio between the amplitude of the oscillatory components and the mean amplitude of the EMG signal was approximately constant over the range within which the phenomenon was observed, corresponding to a peak-to-peak oscillatory amplitude of ∼10% of the mean amplitude. The duration of the periods with stable mean amplitude ranged from a few minutes to ∼1 h, usually interrupted by a sudden change in the activity level or by cessation of the muscle activity. Right and left trapezius muscles presented the same pattern of FM. In supplementary experiments, rhythmic muscle activity pattern was also demonstrated in the upper extremity muscles of deltoid, biceps, and forearm flexor muscles. There was no apparent association between the rhythmic components in the muscle activity pattern and the heart rate variability. To our knowledge, this is the first time that the above-described pattern of EMG activity during sleep is documented. On reanalysis of earlier recorded trapezius motor unit firing pattern in experiments on awake subjects in a situation with mental stress, low-FM of firing with similar frequency content was detected. Possible sources of rhythmic excitation of trapezius motoneurons include slow-wave cortical oscillations represented in descending cortico-spinal pathways, and/or activation by monoaminergic pathways originating in the brain stem reticular formation. The analysis of muscle activity patterns may provide an important new tool to study neural mechanisms in human sleep.


2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Jinzhuang Xiao ◽  
Jinli Sun ◽  
Junmin Gao ◽  
Hongrui Wang ◽  
Xincai Yang

Objectives. Prone bridge, unilateral bridge, supine bridge, and bird-dog are classic rehabilitation exercises, which have been advocated as effective ways to improve core stability among healthy individuals and patients with low back pain. The aim of this study was to investigate the activity of seven selected muscles during rehabilitation exercises through the signal of surface electromyographic. Approaches. We measured the surface electromyographic signals of four lower limb muscles, two abdominal muscles, and one back muscle during rehabilitation exercises of 30 healthy students and then analyzed its activity level using the median frequency method. Results. Different levels of muscle activity during the four rehabilitation exercises were observed. The prone bridge and unilateral bridge caused the greatest muscle fatigue; however, the supine bridge generated the lowest muscle activity. There was no significant difference (P>0.05) between left and right body side muscles in the median frequency slope during the four rehabilitation exercises of seven muscles. Conclusions. The prone bridge can affect the low back and lower limb muscles of most people. The unilateral bridge was found to stimulate muscles much more active than the supine bridge. The bird-dog does not cause much fatigue to muscles but can make most selected muscles active.


2005 ◽  
Vol 289 (5) ◽  
pp. R1338-R1347 ◽  
Author(s):  
Weirong Zhang ◽  
Linda F. Hayward ◽  
Paul W. Davenport

The periaqueductal gray matter is an essential neural substrate for central integration of defense behavior and accompanied autonomic responses. The dorsal half of the periaqueductal gray matter (dPAG) is also involved in mediating emotional responses of anxiety and fear, psychological states that often are associated with changes in ventilation. However, information regarding respiratory modulation elicited from this structure is limited. The present study was undertaken to investigate the relationship between stimulus frequency and magnitude on ventilatory pattern and respiratory muscle activity in urethane-anesthetized, spontaneously breathing rats. Electrical stimulation in the dPAG-recruited abdominal muscle activity increased ventilation and increased respiratory frequency by significantly shortening both inspiratory time and expiratory time. Ventilation increased within the first breath after the onset of stimulation, and the respiratory response increased with increasing stimulus frequency and magnitude. dPAG stimulation also increased baseline EMG activity in the diaphragm and recruited baseline external abdominal oblique EMG activity, normally quiescent during eupneic breathing. Significant changes in cardiorespiratory function were only evoked by stimulus intensities >10 μA and when stimulus frequencies were >10 Hz. Respiratory activity of both the diaphragm and abdominal muscles remained elevated for a minimum of 60 s after cessation of stimulation. These results demonstrate that there is a short-latency respiratory response elicited from the dPAG stimulation, which includes both inspiratory and expiratory muscles. The changes in respiratory timing suggest rapid onset and sustained poststimulus dPAG modulation of the brain stem respiratory network that includes expiratory muscle recruitment.


1999 ◽  
Vol 86 (6) ◽  
pp. 1994-2000 ◽  
Author(s):  
Tadashi Abe ◽  
Takumi Yamada ◽  
Tomoyuki Tomita ◽  
Paul A. Easton

In humans during stimulated ventilation, substantial abdominal muscle activity extends into the following inspiration as postexpiratory expiratory activity (PEEA) and commences again during late inspiration as preexpiratory expiratory activity (PREA). We hypothesized that the timing of PEEA and PREA would be changed systematically by posture. Fine-wire electrodes were inserted into the rectus abdominis, external oblique, internal oblique, and transversus abdominis in nine awake subjects. Airflow, end-tidal CO2, and moving average electromyogram (EMG) signals were recorded during resting and CO2-stimulated ventilation in both supine and standing postures. Phasic expiratory EMG activity (tidal EMG) of the four abdominal muscles at any level of CO2 stimulation was greater while standing. Abdominal muscle activities during inspiration, PEEA, and PREA, were observed with CO2stimulation, both supine and standing. Change in posture had a significant effect on intrabreath timing of expiratory muscle activation at any level of CO2stimulation. The transversus abdominis showed a significant increase in PEEA and a significant decrease in PREA while subjects were standing; similar changes were seen in the internal oblique. We conclude that changes in posture are associated with significant changes in phasic expiratory activity of the four abdominal muscles, with systematic changes in the timing of abdominal muscle activity during early and late inspiration.


2006 ◽  
Vol 31 (4) ◽  
pp. 376-383 ◽  
Author(s):  
Paul Marshall ◽  
Bernadette Murphy

The objective of this study was to determine differences in electromyographic (EMG) activity of prime mover and abdominal muscles while performing squats, push ups, and double leg lowering with a swiss ball. Twelve healthy subjects performed the movements. There was no difference between the surface conditions for muscle activity during the squat exercise; however, individuals had lower perceived exertion for the swiss ball squat. Activity of the triceps and abdominals was highest performing push ups on the swiss ball, whereas the activity of rectus abdominus (RA) only increased during double leg lowering on the swiss ball. Perceived exertion was highest for the push up and leg-lowering exercise performed on the swiss ball. Increased RA activity during double leg lowering can be attributed to its role as a hip flexor, whereas the lack of a rotation aspect to the task prevented increased oblique muscle activity. The swiss ball appears to only increase muscle activity during exercises where the unstable surface is the primary base of support.


2015 ◽  
Vol 95 (12) ◽  
pp. 1617-1627 ◽  
Author(s):  
Lin-Rong Liao ◽  
Gabriel Y.F. Ng ◽  
Alice Y.M. Jones ◽  
Raymond C.K. Chung ◽  
Marco Y.C. Pang

Background Whole-body vibration (WBV) has increasingly been used as an adjunct treatment in neurological rehabilitation. However, how muscle activation level changes during exposure to different WBV protocols in individuals after stroke remains understudied. Objective The purpose of this study was to examine the influence of WBV intensity on the magnitude of biceps femoris (BF) and tibialis anterior (TA) muscle activity and its interaction with exercise and with severity of motor impairment and spasticity among individuals with chronic stroke. Methods Each of the 36 individuals with chronic stroke (mean age=57.3 years, SD=10.7) performed 8 different static exercises under 3 WBV conditions: (1) no WBV, (2) low-intensity WBV (frequency=20 Hz, amplitude=0.60 mm, peak acceleration=0.96g), and (3) high-intensity WBV (30 Hz, 0.44 mm, 1.61g). The levels of bilateral TA and BF muscle activity were recorded using surface electromyography (EMG). Results The main effect of intensity was significant. Exposure to the low-intensity and high-intensity protocols led to a significantly greater increase in normalized BF and TA muscle electromyographic magnitude in both legs compared with no WBV. The intensity × exercise interaction also was significant, suggesting that the WBV-induced increase in EMG activity was exercise dependent. The EMG responses to WBV were similar between the paretic and nonparetic legs and were not associated with level of lower extremity motor impairment and spasticity. Limitations Leg muscle activity was measured during static exercises only. Conclusions Adding WBV during exercise significantly increased EMG activity in the TA and BF muscles. The EMG responses to WBV in the paretic and nonparetic legs were similar and were not related to degree of motor impairment and spasticity. The findings are useful for guiding the design of WBV training protocols for people with stroke.


2004 ◽  
Vol 96 (5) ◽  
pp. 1723-1729 ◽  
Author(s):  
Marieke L. Duiverman ◽  
Leo A. van Eykern ◽  
Peter W. Vennik ◽  
Gerard H. Koëter ◽  
Eric J. W. Maarsingh ◽  
...  

In the present study, we assessed the reproducibility and responsiveness of transcutaneous electromyography (EMG) of the respiratory muscles in patients with chronic obstructive pulmonary disease (COPD) and healthy subjects during breathing against an inspiratory load. In seven healthy subjects and seven COPD patients, EMG signals of the frontal and dorsal diaphragm, intercostal muscles, abdominal muscles, and scalene muscles were derived on 2 different days, both during breathing at rest and during breathing through an inspiratory threshold device of 7, 14, and 21 cmH2O. For analysis, we used the logarithm of the ratio of the inspiratory activity during the subsequent loads and the activity at baseline [log EMG activity ratio (EMGAR)]. Reproducibility of the EMG was assessed by comparing the log EMGAR values measured at test days 1 and 2 in both groups. Responsiveness (sensitivity to change) of the EMG was assessed by comparing the log EMGAR values of the COPD patients to those of the healthy subjects at each load. During days 1 and 2, log EMGAR values of the diaphragm and the intercostal muscles correlated significantly. For the scalene muscles, significant correlations were found for the COPD patients. Although inspiratory muscle activity increased significantly during the subsequent loads in all participants, the COPD patients displayed a significantly greater increase in intercostal and left scalene muscle activity compared with the healthy subjects. In conclusion, the present study showed that the EMG technique is a reproducible and sensitive technique to assess breathing patterns in COPD patients and healthy subjects.


Author(s):  
Yong-Ku Kong ◽  
Chae-Won Park ◽  
Min-Uk Cho ◽  
Seoung-Yeon Kim ◽  
Min-Jung Kim ◽  
...  

The aim of this study was to evaluate the muscle activities and subjective discomfort according to the heights of tasks and the lower-limb exoskeleton CEX (Chairless EXoskeleton), which is a chair-type passive exoskeleton. Twenty healthy subjects (thirteen males and seven females) participated in this experiment. The independent variables were wearing of the exoskeleton (w/ CEX, w/o CEX), working height (6 levels: 40, 60, 80, 100, 120, and 140 cm), and muscle type (8 levels: upper trapezius (UT), erector spinae (ES), middle deltoid (MD), triceps brachii (TB), biceps brachii (BB), biceps femoris (BF), rectus femoris (RF), and tibialis anterior (TA)). The dependent variables were EMG activity (% MVC) and subjective discomfort rating. When wearing the CEX, the UT, ES, RF, and TA showed lower muscle activities at low working heights (40–80 cm) than not wearing the CEX, whereas those muscles showed higher muscle activities at high working heights (100–140 cm). Use of the CEX had a positive effect on subjective discomfort rating at lower working heights. Generally, lower discomfort was reported at working heights below 100 cm when using the CEX. At working heights of 100–140 cm, the muscle activity when wearing the CEX tended to be greater than when not wearing it. Thus, considering the results of this study, the use of the lower-limb exoskeleton (CEX) at a working height of 40–100 cm might reduce the muscle activity and discomfort of whole body and decrease the risk of related disorders.


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