scholarly journals Investigation of lower limb’s muscles activity during performance of salat between two age groups

2019 ◽  
Vol 14 (2) ◽  
pp. 608
Author(s):  
N. Abdul Malik ◽  
Z. Wahid ◽  
A. F. Zulkipili ◽  
S. Noorjannah Ibrahim ◽  
T. S. Gunawan ◽  
...  
Keyword(s):  
Muscle Activity ◽  
Age Groups ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Surface Emg ◽  
Active Muscle ◽  
Factors Affecting ◽  
Significant Difference ◽  
Result Show ◽  
Two Age Groups

Muscles play an important role in the movement of limbs. They undergo contraction to straighten or to bend a joint for the limbs to move. There are many factors that can affect muscle activity. Age could be one of the possible factors affecting muscle activity. The purpose of this study was to investigate the lower limb’s muscles activity during performance of <em>salat</em> between two age groups. The lower limb’s muscles investigated were Gastrocnemius (GAS), Biceps Femoris (BF), Tibialis Anterior (TA) and Rectus Femoris (RF). The postures involve are standing, bowing, prostrating and sitting. The electromyography (EMG) signals of the muscles were measured using the technique of surface EMG (sEMG). The signals were acquired by using Delsys Bagnoli™ Desktop sEMG system and EMGworks®. Ten healthy subjects from two age groups were recruited in this study. The first group consists of five males aged between 20 to 29 while the second group consists of five males aged above 40. The raw EMG signals acquired were analyzed and the EMG envelopes were developed using MATLAB. The averaged RMS values of EMG for each muscle were also calculated. Analysis of variance (ANOVA) of the EMGs was obtained by using <em>F</em>-test. Further investigation of the variance was performed by using Tukey comparison. From the results, the most active muscle during the performance of <em>salat</em> is BF while the less active muscle is GAS for both age groups. The statistical result show that there is no difference in the muscle activity pattern between the two age groups but there is significant difference among the muscles investigated.

scholarly journals Electromyographic responses to Nordic curl and prone leg curl exercises in football players

2021 ◽  
Vol 25 (5) ◽  
pp. 288-298
Author(s):  
Murat Çilli ◽  
Merve N. Yasar ◽  
Onur Çakir
Keyword(s):  
Muscle Activity ◽  
Muscle Activation ◽  
Total Duration ◽  
Rectus Femoris ◽  
Random Order ◽  
Biceps Femoris ◽  
Activation Rate ◽  
Significant Difference ◽  
Activation Rates ◽  
Short Time

Background and Study Aim. The aim of this study is to examine the electromyographic responses to Nordic curl and prone leg curl exercises, having two different mechanics. Material and Methods. The athletes performed the prone leg curl and Nordic curl exercises in random order, 6 repetitions each. Electromyographic data of semimemranosus, semitendinosus, biceps femoris and rectus femoris muscles were recorded by 8-channel electromyography in order to examine the muscle responses to exercises. Total duration of exercise, cumulative integrated electromyographic values and muscle activation rates in 5 different intensity zones determined according to MVC% values have been compared. Results. Prone leg curl exercise occurred in less time than Nordic curl exercise. According to the cumulative integrated electromyography data results, all muscles showed similar muscle activation in both exercises. Comparing the muscle activation rates in the five intensity zones, more muscle activity was observed for Nordic curl exercise in the first intensity zone, while prone leg curl exercise was more active in the third and fourth zones. During the prone leg curl exercise, the muscle activation rate of the dominant leg is higher in the first intensity zone, whereas the non-dominant leg in the fourth intensity zone has a higher muscle activation. During the Nordic curl exercise, the muscle activation rates of the dominant leg in the first and fifth intensity zones are higher, whereas the nondominant leg in the fourth intensity zone is higher. Conclusions. Prone leg curl exercises can be preferred in order to stimulate high muscle activation in a short time. Comparing the two exercises there was no significant difference in muscle activity in dominant and nondominant legs.

scholarly journals Standing on elevated platform changes postural responses during arm movement

2020 ◽  
Author(s):  
Luis Mochizuki ◽  
Juliana Pennone ◽  
Aline Bigongiari ◽  
Renata Garrido Cosme ◽  
Monique Oliveira Baptista Cajueiro ◽  
...  
Keyword(s):  
Postural Control ◽  
Muscle Activity ◽  
Stable Condition ◽  
Arm Movement ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Surface Emg ◽  
Postural Adjustment ◽  
Postural Responses ◽  
Before And After

AbstractThis study investigated the muscle activity during the preparatory (anticipatory postural adjustment, APA), execution (online postural adjustments, OPA), and compensatory (compensatory postural adjustment, CPA) phases during standing with eyes opened or closed on an elevated platform. Eight healthy young women stood in the upright position, with eyes opened or closed, and did as-fast-as-they-could shoulder flexions on the ground and on 1-m-height-portable-elevated-platform. The surface EMG of trunk (lumbar extensor, and rectus abdominis) and lower limb (rectus femoris, biceps femoris, tibialis anterior and gastrocnemius lateralis) muscles during this task were recorded (1 kHz sampling frequency) and compared during these three phases. Analysis of variance was applied to compare the effects of height (floor and elevated platform), vision (open and closed), and postural adjustment (APA, OPA and CPA) into the activity of each muscle. These muscles were more active during OPA (p<0.0001) and less active during APA. On the elevated platform, these postural muscles presented more activty during APA (p<0.001). During the most stable condition (on the ground with eyes opened), muscle activity during APA and OPA was negatively correlated, and not correlated between OPA and CPA. Our results suggest postural control adapts to sensory, motor, and cognitive conditions. Therefore, the increased demand for postural control, generated due to the height of the support base, provokes the need for greater flexibility of postural synergies and causes a change in muscle activity.Summary StatementWe discuss how postural muscle activity behaves before and after a fast upper arms movement when someone stands on a elevated platform or on the ground.

Lower-Extremity Muscle Activity During Aquatic and Land Treadmill Running at the Same Speeds

2014 ◽  
Vol 23 (2) ◽  
pp. 107-122 ◽  
Author(s):  
W. Matthew Silvers ◽  
Eadric Bressel ◽  
D. Clark Dickin ◽  
Garry Killgore ◽  
Dennis G. Dolny
Keyword(s):  
Lower Extremity ◽  
Outcome Measures ◽  
Muscle Activity ◽  
Tibialis Anterior ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Swing Phase ◽  
Treadmill Running ◽  
Vastus Medialis ◽  
Lower Extremity Muscle

Context:Muscle activation during aquatic treadmill (ATM) running has not been examined, despite similar investigations for other modes of aquatic locomotion and increased interest in ATM running.Objectives:The objectives of this study were to compare normalized (percentage of maximal voluntary contraction; %MVC), absolute duration (aDUR), and total (tACT) lower-extremity muscle activity during land treadmill (TM) and ATM running at the same speeds.Design:Exploratory, quasi-experimental, crossover design.Setting:Athletic training facility.Participants:12 healthy recreational runners (age = 25.8 ± 5 y, height = 178.4 ± 8.2 cm, mass = 71.5 ± 11.5 kg, running experience = 8.2 ± 5.3 y) volunteered for participation.Intervention:All participants performed TM and ATM running at 174.4, 201.2, and 228.0 m/min while surface electromyographic data were collected from the vastus medialis, rectus femoris, gastrocnemius, tibialis anterior, and biceps femoris.Main Outcome Measures:For each muscle, a 2 × 3 repeated-measures ANOVA was used to analyze the main effects and environment–speed interaction (P ≤ .05) of each dependent variable: %MVC, aDUR, and tACT.Results:Compared with TM, ATM elicited significantly reduced %MVC (−44.0%) but increased aDUR (+213.1%) and tACT (+41.9%) in the vastus medialis, increased %MVC (+48.7%) and aDUR (+128.1%) in the rectus femoris during swing phase, reduced %MVC (−26.9%) and tACT (−40.1%) in the gastrocnemius, increased aDUR (+33.1%) and tACT (+35.7%) in the tibialis anterior, and increased aDUR (+41.3%) and tACT (+29.2%) in the biceps femoris. At faster running speeds, there were significant increases in tibialis anterior %MVC (+8.6−15.2%) and tACT (+12.7−17.0%) and rectus femoris %MVC (12.1−26.6%; swing phase).Conclusion:No significant environment–speed interaction effects suggested that observed muscle-activity differences between ATM and TM were due to environmental variation, ie, buoyancy (presumed to decrease %MVC) and drag forces (presumed to increase aDUR and tACT) in the water.

Phylogenetic group and serotype of E. coli isolates are important risk factors affecting intensity of colibacillosis in broilers

2018 ◽  
Author(s):  
S. Kumar ◽  
R. Gupta ◽  
N. Jindal and Y.C. Bangar
Keyword(s):  
Case Fatality Rate ◽  
Age Groups ◽  
Case Fatality ◽  
Phylogenetic Group ◽  
Fatality Rate ◽  
Phylogenetic Groups ◽  
Factors Affecting ◽  
E Coli ◽  
Significant Difference ◽  
Class 1

The study was conducted on 106 E. coli isolates to determine the phylogenetic group, serotype and carriage of Class 1 integrons in isolates and ascertain their association along with other parameters with vital disease measures in broiler flocks affected with colibacillosis. Out of 32 isolates of which “O” antigen was characterized, serogroup O2 comprising of 12 (37.5%) isolates was most prevalent in the present study. Most of the isolates (85/106; 80.19%) belonged to phylogenetic group B2. Mean apparent morbidity, mortality and case fatality rate (CFR) were 3.77%, 2.32% and 61.49%, respectively. There was significant difference in number of outbreaks reported in different age groups (p less than 0.0001). Also, there was significant association between phylogenetic group and age of outbreak due to E. coli (p=0.024). Comparatively, no significant association was observed between age of outbreaks and serotypes (p=0.980). There was significant association between various disease measures and E. coli isolates affiliated to various phylogenetic groups and serotypes. All the measures (apparent morbidity, mortality and CFR) of disease were highest in outbreaks due to isolates of phylogenetic group B2 and serogroup O20. However, the measures were not significantly affected by the presence of integrons in the E. coli.

scholarly journals Kinematic and EMG Comparison Between Variations of Unilateral Squats Under Different Stabilities

2020 ◽  
Vol 4 (02) ◽  
pp. E59-E66
Author(s):  
Roland van den Tillaar ◽  
Stian Larsen
Keyword(s):  
Muscle Activity ◽  
Rectus Femoris ◽  
Gluteus Medius ◽  
Biceps Femoris ◽  
Peak Force ◽  
Erector Spinae ◽  
Trunk Muscles ◽  
Training Experience ◽  
Free Weight ◽  
Weight Condition

AbstractThe purpose of the study was to compare kinematics and muscle activity between two variations of unilateral squats under different stability conditions. Twelve male volunteers (age: 23±5 years, mass: 80±17 kg, height: 1.81±0.11 m, strength-training experience: 4.3±1.9 years) performed four repetitions with the same external load (≈4RM). Two variations (with the non-stance leg forwards vs. backwards) were performed in a Smith-machine and free-weight condition. The variables were barbell velocity, lifting time and surface electromyography activity of the lower extremity and trunk muscles during the descending and ascending phase. The main findings were 1) peak force was higher when performing the unilateral squats in the Smith machine; 2) peak ascending barbell velocity increased from repetition 3–4 with free weight; and 3) muscle activity from the rectus femoris, vastus lateral, biceps femoris, gluteus medius, and erector spinae increased with repetitions, whereas gluteus, and medial vastus and shank muscles were affected by the conditions. It was concluded that more peak force could be produced because of increased stability. However, peak barbell velocity increased from repetition to repetition in free-weight unilateral squats, which was probably because the participants grew more comfortable. Furthermore, increased instability causes more gluteus and vastus medial activation and foot variations mainly affected the calf muscles.

Character introductions in oral narratives of Swedish–German bilingual preschoolers

2020 ◽  
pp. 014272371989744
Author(s):  
Josefin Lindgren ◽  
Valerie Reichardt ◽  
Ute Bohnacker
Keyword(s):  
Language Proficiency ◽  
Language Skills ◽  
Age Groups ◽  
Age Group ◽  
Morphological Form ◽  
Information Status ◽  
Significant Difference ◽  
Old Swedish ◽  
As Effects ◽  
Two Age Groups

Closely related Swedish and German both mark information status of referents morphologically, though little is known about its acquisition. This study investigates character introductions in the narratives of 4- and 6-year-old Swedish–German bilinguals ( N = 40) in both languages, elicited with MAIN Cat/Dog. We analyse effects of age group, language and animacy (human vs nonhuman characters) on the type of referring expression (indefinite NP and pronoun), as well as effects of language proficiency and exposure on the use of indefinite NPs for each language. We also explore which syntactic constructions indefinite NPs occur in. A significant difference was found between the two age groups, but not between languages. No effect was found of language skills or exposure. Four-year-olds used more pronouns and a lower proportion of indefinite NPs than 6-year-olds. Pronouns were more frequent for the human character than for nonhuman animate characters. Whilst animacy (humanness) promoted the use of pronouns, it did not affect the choice of morphological form for lexical NPs (indefinite/definite). The age groups differed in how indefinite NPs were used. Four-year-olds produced fewer narrative presentations (where a character is introduced as part of a typical story opening, e.g. Once upon a time there was a cat) than 6-year-olds, and more labellings (with only an NP, or a clausal predicative, e.g. That’s a cat). Qualitative analyses suggest that the children’s indefinite NPs in labelling constructions can be both referential (when setting the narrative scene), and type-denoting (when naming referents in individual pictures). Whilst the children’s abilities to introduce story characters develop measurably from 4 to 6 years in Swedish and German, appropriateness of character introductions not only depends on whether an indefinite NP is chosen, but also on the syntactic construction this indefinite NP is used in.

scholarly journals Neuromuscular changes of the aged human hamstrings

2018 ◽  
Vol 120 (2) ◽  
pp. 480-488 ◽  
Author(s):  
Eric A. Kirk ◽  
Kevin J. Gilmore ◽  
Charles L. Rice
Keyword(s):  
Motor Unit ◽  
Contractile Function ◽  
Age Groups ◽  
Biceps Femoris ◽  
Surface Emg ◽  
Muscle Group ◽  
Voluntary Activation ◽  
Discharge Rates ◽  
Age Related ◽  
Motor Unit Discharge

Despite the life-long importance for posture and locomotion, neuromuscular properties of the hamstrings muscle have not been explored with adult aging. The purpose of this study was to assess and compare age-related effects on contractile function, spinal motor neuron output expressed as motor unit (MU) discharge rates in the hamstrings of 11 young (26 ± 4 yr) and 10 old (80 ± 5 yr) men. Maximal voluntary isometric contractions (MVC), stimulated contractile properties, and surface and intramuscular electromyography (EMG) from submaximal to MVC were recorded in the biceps femoris (BF) and semimembranosus-semitendinosus (SS) muscles. MVC torque was ~50% less in the old with both age groups attaining ≥93% mean voluntary activation. Evoked twitches in the old were ~50% lower in amplitude and >150% longer in duration compared with those in the young. At successive voluntary contractions of 25, 50, and 100% MVC, MU discharge rates were up to 45% lower in old, with no differences in relative submaximal surface EMG between age groups. Furthermore, the old had significantly lower MU discharge rates in the SS at all contraction intensities compared with the BF muscle. Men in their 8th to 10th decades of life demonstrate substantially lower strength and MU discharge rates in this functionally important large lower limb muscle group, with greater age-related effect on discharge rates in the medial hamstrings. These findings, compared with those in other muscles studied, highlight that the neuromuscular properties of limb muscles, and indeed within functionally similar portions of a muscle group, are not all affected equally by the aging process. NEW & NOTEWORTHY In the hamstrings, we found that both contractile function and motor unit discharge rates across the range of voluntary intensities were lower in the old. The differences in discharge rates due to age were greater in the medial hamstrings muscle group compared with the lateral hamstrings. Compared with previous studies, these results highlight that not all muscles are affected equally by aging and there may be compartmental differences within functionally similar muscles.

scholarly journals Stumbling Over Obstacles in Older Adults Compared to Young Adults

2005 ◽  
Vol 94 (2) ◽  
pp. 1158-1168 ◽  
Author(s):  
A. M. Schillings ◽  
Th. Mulder ◽  
J. Duysens
Keyword(s):  
Older Adults ◽  
Young Adults ◽  
Age Groups ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Risk Of Falling ◽  
Leg Muscles ◽  
Long Latency Responses ◽  
Long Latency ◽  
Movement Strategies

Falls are a major problem in older adults. Many falls occur because of stumbling. The aim of the present study is to investigate stumbling reactions of older adults and to compare them with young adults. While subjects walked on a treadmill, a rigid obstacle unexpectedly obstructed the forward sway of the foot. In general, older adults used the same movement strategies as young adults (“elevating” and “lowering”). The electromyographic responses were categorized according to latencies: short-latency (about 45 ms, RP1), medium-latency (about 80 ms, RP2), and long-latency responses (about 110 ms, RP3; about 160 ms, RP4). Latencies of RP1 responses increased by about 6 ms and of RP2 by 10–19 ms in older adults compared with the young. Amplitudes of RP1 were similar for both age groups, whereas amplitudes of RP2–RP4 could differ. In the early-swing elevating strategy (perturbed foot directly lifted over the obstacle) older adults showed smaller responses in ipsilateral upper-leg muscles (biceps femoris and rectus femoris). This was related to shorter swing durations, more shortened step distances, and more failures in clearing the obstacle. In parallel, RP4 activity in the contralateral biceps femoris was enhanced, possibly pointing to a higher demand for trunk stabilization. In the late-swing lowering strategy (foot placed on the treadmill before clearing the obstacle) older adults showed lower RP2–RP3 responses in most muscles measured. However, kinematic responses were similar to those of the young. It is concluded that the changes in muscular responses in older adults induce a greater risk of falling after tripping, especially in early swing.

scholarly journals Antimicrobial Resistance in Fecal Escherichia coli Isolates from Healthy Urban Children of Two Age Groups in Relation to Their Antibiotic Therapy

2011 ◽  
Vol 55 (6) ◽  
pp. 3005-3007 ◽  
Author(s):  
Ivan Literak ◽  
Radim Petro ◽  
Monika Dolejska ◽  
Erika Gruberova ◽  
Hana Dobiasova ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Czech Republic ◽  
Antimicrobial Resistance ◽  
Age Groups ◽  
Antibiotic Resistant ◽  
The Czech Republic ◽  
Content Type ◽  
E Coli ◽  
Significant Difference ◽  
Two Age Groups

ABSTRACTThe study was performed in the Czech Republic during 2007 to 2009. OfEscherichia coliisolates from 275 children aged 6 weeks, 36% (n= 177) were resistant to 1 to 7 antibiotics. Of isolates from 253 children aged 6 to 17 years, 24% (n= 205) were resistant to 1 to 5 antibiotics. There was no significant difference in the prevalences of antibiotic-resistantE. coliisolates between these groups of children, even though the consumptions of antibiotics were quite different.

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