scholarly journals Patterns Of Circular And Radial Mantle Muscle Activity in Respiration and Jetting of the Squid Loligo Opalescens

1983 ◽  
Vol 104 (1) ◽  
pp. 97-109 ◽  
Author(s):  
JOHN M. GOSLINE ◽  
JOHN D. STEEVES ◽  
ANTHONY D. HARMAN ◽  
M. EDWIN DEMONT
Keyword(s):  
Muscle Activity ◽  
Circular Muscle ◽  
Muscular Activity ◽  
Mantle Cavity ◽  
Emg Activity ◽  
Small Contribution ◽  
Tissue Elasticity ◽  
Elastic Recoil ◽  
Loligo Opalescens ◽  
Muscle Groups

1. By simultaneously recording the electromyographic (EMG) activity of squid mantle muscles, changes in mantle cavity pressure and changes in mantle diameter, we have been able to distinguish the pattern of radial muscle activity from circular muscle activity, and in so doing were able to determine the functional role of these muscle groups in motor behaviours. 2. Three distinguishable phases of activity appear during escape jets: (i), hyper-inflation brought about by the contraction of the radial muscles; (ii), the jet powered by the contraction of circular muscles; and (iii), refilling powered largely by the elastic recoil of the mantle wall, but with a small contribution from the radial muscles. 3. Two distinctly different patterns of muscular activity were seen in respiratory movements. One pattern (pattern I) is powered by the radial muscles alone, while the other (pattern II) is powered by the circular muscles alone. In both modes of respiration, the muscles are apparently antagonized by tissue elasticity. 4. Thus, the storage of elastic energy in the connective tissue fibre-lattice of the mantle wall plays a very important role in both modes of squid movement.

Myoelectric Activity Differences in Three Learning Sessions

2002 ◽  
Vol 16 (2) ◽  
pp. 92-96
Author(s):  
Tiina Ritvanen ◽  
Reijo Koskelo ◽  
Osmo H„nninen
Keyword(s):  
High School Students ◽  
Muscle Activity ◽  
Muscle Tension ◽  
Emg Activity ◽  
Traditional Learning ◽  
Myoelectric Activity ◽  
School Students ◽  
Language Laboratory ◽  
Upper Trapezius ◽  
Muscle Groups

Abstract This study follows muscle activity in three different learning sessions (computer, language laboratory, and normal classroom) while students were studying foreign languages. Myoelectric activity was measured in 21 high school students (10 girls, 11 boys, age range 17-20 years) by surface electromyography (sEMG) from the upper trapezius and frontalis muscles during three 45-min sessions. Root mean square (RMS) average from both investigated muscles was calculated. The EMG activity was highest in both muscle groups in the computer-aided session and lowest in the language laboratory. The girls had higher EMG activity in both investigated muscle groups in all three learning situations. The measured blood pressure was highest at the beginning of the sessions, decreased within 10 min, but increased again toward the end of the sessions. Our results indicate that the use of a computer as a teaching-aid evokes more constant muscle activity than the traditional learning situations. Since muscle tension can have adverse health consequences, more research is needed to determine optimal classroom conditions, especially when technical aids are used in teaching.

scholarly journals Muscle activation varies between high-bar and low-bar back squat

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9256
Author(s):  
Michal Murawa ◽  
Anna Fryzowicz ◽  
Jaroslaw Kabacinski ◽  
Jakub Jurga ◽  
Joanna Gorwa ◽  
...  
Keyword(s):  
Motion Capture ◽  
Muscle Activation ◽  
Muscular Activity ◽  
Load Level ◽  
Emg Activity ◽  
Bioelectrical Activity ◽  
Kinematic Data ◽  
Back Squat ◽  
Muscle Groups ◽  
External Loads

Background Differences in the muscular activity between the high-bar back squat (HBBS) and the low-bar back squat (LBBS) on the same representative group of experienced powerlifters are still scarcely investigated. The main purpose of the study was to compare the normalized bioelectrical activity and maximal angles within single homogeneous group between the HBBS and LBBS for 60% one repetition maximum (1RM), 65% 1RM and 70% 1RM. Methods Twelve healthy men (age 24.3  ± 2.8 years, height 178.8  ± 5.6 cm, body mass 88.3  ± 11.5 kg), experienced in powerlifting performed HBBS and LBBS with comparable external loads equal 60% 1RM, 65% 1RM, and 70% 1RM. Electromyography (EMG) signals of muscle groups were synchronously recorded alongside kinematic data (joints angle) by means of a motion capture system. Results EMG activity during eccentric phase of squat motion were significantly higher during LBBS than in HBBS for all selected muscles (60% 1RM and 65% 1RM) (p < 0.05). All examined muscles were more activated during concentric phase of the squat cycle (p < 0.05). In the concentric phase, significant differences between the loads were generally not observed between just 5% 1RM change in load level for LBBS. Conclusions Our results confirmed significant differences in muscles activation between both squat techniques. Muscle activity during eccentric phase of squat motion were significantly higher during LBBS than HBBS. The differences are crucial for posterior muscle chain during eccentric phase of squat cycle.

scholarly journals Walking With a Robotic Exoskeleton Does Not Mimic Natural Gait: A Within-Subjects Study (Preprint)

2018 ◽  
Author(s):  
Chad Swank ◽  
Sharon Wang-Price ◽  
Fan Gao ◽  
Sattam Almutairi
Keyword(s):  
Lower Extremity ◽  
Muscle Activity ◽  
Stance Phase ◽  
Swing Phase ◽  
Healthy Adults ◽  
Emg Activity ◽  
Robotic Exoskeleton ◽  
Gait Parameters ◽  
Muscle Groups ◽  
The Impact

BACKGROUND Robotic exoskeleton devices enable individuals with lower extremity weakness to stand up and walk over ground with full weight-bearing and reciprocal gait. Limited information is available on how a robotic exoskeleton affects gait characteristics. OBJECTIVE The purpose of this study was to examine whether wearing a robotic exoskeleton affects temporospatial parameters, kinematics, and muscle activity during gait. METHODS The study was completed by 15 healthy adults (mean age 26.2 [SD 8.3] years; 6 males, 9 females). Each participant performed walking under 2 conditions: with and without wearing a robotic exoskeleton (EKSO). A 10-camera motion analysis system synchronized with 6 force plates and a surface electromyography (EMG) system captured temporospatial and kinematic gait parameters and lower extremity muscle activity. For each condition, data for 5 walking trials were collected and included for analysis. RESULTS Differences were observed between the 2 conditions in temporospatial gait parameters of speed, stride length, and double-limb support time. When wearing EKSO, hip and ankle range of motion (ROM) were reduced and knee ROM increased during the stance phase. However, during the swing phase, knee and ankle ROM were reduced when wearing the exoskeleton bionic suit. When wearing EKSO, EMG activity decreased bilaterally in the stance phase for all muscle groups of the lower extremities and in the swing phase for the distal muscle groups (tibialis anterior and soleus) as well as the left medial hamstrings. CONCLUSIONS Wearing EKSO altered temporospatial gait parameters, lower extremity kinematics, and muscle activity during gait in healthy adults. EKSO appears to promote a type of gait that is disparate from normal gait in first-time users. More research is needed to determine the impact on gait training with EKSO in people with gait impairments.

scholarly journals Electrophysiology of Muscle Fatigue in Cardiopulmonary Resuscitation on Manikin Model

2018 ◽  
Vol 65 (1) ◽  
pp. 30-37 ◽  
Author(s):  
Carlos Cobo-Vázquez ◽  
Gemma De Blas ◽  
Pablo García-Canas ◽  
María del Carmen Gasco-García,
Keyword(s):  
Cardiopulmonary Resuscitation ◽  
Muscle Fatigue ◽  
Muscle Activity ◽  
Muscular Activity ◽  
Chest Compressions ◽  
Paired Samples ◽  
Lumbar Muscle ◽  
Muscle Groups ◽  
Student’S T ◽  
Spinal Muscles

Cardiopulmonary resuscitation requires the provider to adopt positions that could be dangerous for his or her spine, specifically affecting the muscles and ligaments in the lumbar zone and the scapular spinal muscles. Increased fatigue caused by muscular activity during the resuscitation could produce a loss of quality and efficacy, resulting in compromising resuscitation. The aim of this study was to evaluate the maximum time a rescuer can perform uninterrupted chest compressions correctly without muscle fatigue. This pilot study was performed at Universidad Complutense de Madrid (Spain) with the population recruited following CONSORT 2010 guidelines. From the 25 volunteers, a total of 14 students were excluded because of kyphoscoliosis (4), lumbar muscle pain (1), anti-inflammatory treatment (3), or not reaching 80% of effective chest compressions during the test (6). Muscle activity at the high spinal and lumbar (L5) muscles was assessed using electromyography while students performed continuous chest compressions on a ResusciAnne manikin. The data from force exerted were analyzed according to side and muscle groups using Student's t test for paired samples. The influence of time, muscle group, and side was analyzed by multivariate analyses (p ≤ .05). At 2 minutes, high spinal muscle activity (right: 50.82 ± 9.95; left: 57.27 ± 20.85 μV/ms) reached the highest values. Activity decreased at 5 and 15 minutes. At 2 minutes, L5 activity (right: 45.82 ± 9.09; left: 48.91 ± 10.02 μV/ms) reached the highest values. After 5 minutes and at 15 minutes, activity decreased. Fatigue occurred bilaterally and time was the most important factor. Fatigue began at 2 minutes. Rescuers exert muscular countervailing forces in order to maintain effective compressions. This imbalance of forces could determine the onset of poor posture, musculoskeletal pain, and long-term injuries in the rescuer.

scholarly journals Bite-to-bite variation of muscular activity in cats

1990 ◽  
Vol 151 (1) ◽  
pp. 1-19
Author(s):  
C. Gans ◽  
G. C. Gorniak ◽  
W. K. Morgan
Keyword(s):  
Muscle Activity ◽  
Neural Control ◽  
Muscular Activity ◽  
Relative Magnitude ◽  
Emg Activity ◽  
Jaw Movements ◽  
Food Texture

Changes in electromyographic (EMG) activity between successive bites in the jaw-closing muscles of cats are described for the reduction of food with different textures. Plots of these data suggest, and statistics confirm, that one cannot predict the magnitude of EMG activity from one bite to the next, but that predicting the direction of change in EMG activity (i.e. increases or decreases) may be possible, given the relative magnitude of a bite. The patterns observed also show that the degree of variability between masticatory cycles differs among the jaw-closing muscles and with food texture. These patterns of muscle activity are related to the neural control of jaw movements.

scholarly journals Muscle Activity Asymmetry of the Lower Limbs During Sprinting in Elite Soccer Players

2020 ◽  
Vol 75 (1) ◽  
pp. 239-245
Author(s):  
Przemysław Pietraszewski ◽  
Artur Gołaś ◽  
Aleksander Matusiński ◽  
Sylwia Mrzygłód ◽  
Aleksandra Mostowik ◽  
...  
Keyword(s):  
Muscle Activity ◽  
Body Height ◽  
Lower Limbs ◽  
Soccer Players ◽  
Emg Activity ◽  
Professional Soccer ◽  
Left And Right ◽  
Muscle Groups ◽  
The Right ◽  
Lh Rh

Abstract The analysis of movement patterns through EMG activity provides the opportunity to identify the muscle groups most involved in a particular exercise, and to determine the scope of inter-limb deficiencies. The aim of the present study was to investigate the effects of a side-to-side muscle activity asymmetry between the left and the right lower limb during sprinting in soccer players. Sixteen professional soccer players took part in the study. Their age, body mass and body height equaled 23.7 ± 7.6 years, 81.2 ± 10.8 kg and 179.3 ± 12.2 cm, respectively. The sprint test consisted of two maximal sprints over 30 m with a 5-min rest interval between each sprint. EMG was recorded bilaterally from the quadriceps, hamstrings and gluteal muscles. Regression analysis revealed a significant effect of a side-to-side average muscle activity asymmetry between the left and right hamstring (LH/RH) muscles during the speed tests at 5 m (p = 0.044), and 30 m (p = 0.045), as well as the left and right glutes (LG/RG) at 5 m (p = 0.044) and 30 m (p = 0.043). Our results indicate that hamstring and glute muscles should be selectively and additionally activated during resistance training in soccer players to prevent injuries and improve sprint performance.

Muscular Activity of the Mantle of Sepia and Loligo (Cephalopoda) During Respiratory Movements and Jetting, and Its Physiological Interpretation

1974 ◽  
Vol 61 (2) ◽  
pp. 411-419
Author(s):  
A. PACKARD ◽  
E. R. TRUEMAN
Keyword(s):  
Surface Area ◽  
Circular Muscle ◽  
Muscular Activity ◽  
Mantle Cavity ◽  
Natural Conditions ◽  
Respiratory Movements

1. The action of the mantle of Sepia and Loligo has been monitored under nearly natural conditions. Respiratory movements are confined to the anterior mantle whilst during jet cycles the circular muscles contract powerfully throughout the mantle. 2. Contraction of circular muscle results in thickening of the mantle and expulsion of water from the mantle cavity. Activity of radial muscles causes the mantle to become thinner and to expand in surface area so as to inhale water. 3. During such movements these two groups of muscles antagonize each other directly without the participation of a discrete skeleton.

On the respiratory flow in the cuttlefish sepia officinalis.

1994 ◽  
Vol 194 (1) ◽  
pp. 153-165 ◽  
Author(s):  
Q Bone ◽  
E Brown ◽  
G Travers
Keyword(s):  
Connective Tissue ◽  
Circular Muscle ◽  
Mantle Cavity ◽  
Respiratory Pattern ◽  
Muscle Fibres ◽  
Sepia Officinalis ◽  
Cavity Pressure ◽  
Elastic Recoil ◽  
Respiratory Flow ◽  
Large Pressure

The respiratory flow of water over the gills of the cuttlefish Sepia officinalis at rest is produced by the alternate activity of the radial muscles of the mantle and the musculature of the collar flaps; mantle circular muscle fibres are not involved. Inspiration takes place as the radial fibres contract, thinning the mantle and expanding the mantle cavity. The rise in mantle cavity pressure (up to 0.15 kPa), expelling water via the siphon during expiration, is brought about by inward movement of the collar flaps and (probably) mainly by elastic recoil of the mantle connective tissue network 'wound up' by radial fibre contraction during inspiration. Sepia also shows a second respiratory pattern, in which mantle cavity pressures during expiration are greater (up to 0.25 kPa). Here, the mantle circular fibres are involved, as they are during the large pressure transients (up to 10 kPa) seen during escape jetting. Active contraction of the muscles of the collar flaps is seen in all three patterns of expulsion of water from the mantle cavity, electrical activity increasing with increasing mantle cavity pressures. Respiratory expiration in the resting squid Loligo vulgaris is probably driven as in Sepia, whereas in the resting octopus Eledone cirrhosa, the mantle circular musculature is active during expiration. The significance of these observations is discussed.

Excitatory and Inhibitory Control of Inherent Contractions in the Sea Anemone Calliactis Parasitica

1974 ◽  
Vol 60 (2) ◽  
pp. 397-422
Author(s):  
I. D. MCFARLANE
Keyword(s):  
Electrical Stimulation ◽  
Circular Muscle ◽  
Muscular Activity ◽  
Pulse Frequency ◽  
Muscle Contractions ◽  
Nerve Net ◽  
Calliactis Parasitica ◽  
Muscle Groups ◽  
Contraction Cycle ◽  
Stimulation Of

1. Bursts of nerve-net activity are always followed by a contraction cycle involving parietal and circular muscle contractions in isolated preparations of Calliactis parasitica. Both muscle groups can, however, also contract in the absence of nerve-net activity. These contractions, termed inherent, seem to follow periods of reduced activity in the endodermal slow conduction system (SS2). 2. Electrical stimulation of the SS2 inhibits inherent contractions of parietal and circular muscle preparations. Electrical stimulation of the nerve net excites parietal muscles but seems to have both excitatory and inhibitory effects on circular muscles. 3. A model for control of parietal and circular muscle contractions proposes that both the nerve net and the SS2 are responsible for directing the inherent muscular activity into the observed contraction cycle. It is suggested that when the action of these antagonistic muscles is strongly opposed the SS2 pulse frequency rises, resulting in inhibition of further muscular activity.

Simulate and sense force exertions during virtual patient transfer tasks

2020 ◽  
Vol 64 (1) ◽  
pp. 2092-2096
Author(s):  
Ken Chen ◽  
Rebecca Widmayer ◽  
Karen B. Chen
Keyword(s):  
Muscle Activity ◽  
Fine Tuning ◽  
Activity Levels ◽  
Patient Lifting ◽  
Perceived Workload ◽  
Specific Muscle ◽  
Muscle Groups ◽  
Forceful Exertion ◽  
Lifting Task ◽  
Transfer Tasks

Virtual reality (VR) is commonplace for training, yet simulated physical activities in VR do not require trainees to engage and contract the muscle groups normally engaged in physical lifting. This paper presents a muscle activity-driven interface to elicit the sensation of forceful, physical exertions when lifting virtual objects. Users contracted and attained predefined muscle activity levels that were calibrated to user-specific muscle activity when lifting the physical counterpart. The overarching goal is to engage the appropriate muscles, and thereby encourage and elicit behaviors normally seen in the physical environment. Activities of 12 key muscles were monitored using electromyography (EMG) sensors while they performed a three-part patient lifting task in a Cave Automatic Virtual Environment. Participants reported higher task mental loads and less physical loads for the virtual lift than the physical lift. Findings suggest the potential to elicit sensation of forceful exertion via EMG feedback but needed fine-tuning to offset perceived workload.

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