Acceleration Profiles and the Isoinertial Squatting Exercise: Is There a Direct Effect on Concentric–Eccentric Force, Power, and Neuromuscular Efficiency?

2020 ◽  
pp. 1-7
Author(s):  
Denys Batista Campos ◽  
Isabella Christina Ferreira ◽  
Matheus Almeida Souza ◽  
Macquiden Amorim ◽  
Leonardo Intelangelo ◽  
...  
Keyword(s):  
Vastus Lateralis ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Cross Sectional Study ◽  
Force Output ◽  
Optical Encoder ◽  
Mean Power ◽  
Cross Sectional ◽  
Linear Envelope ◽  
The University

Objective: To examine the selective influences of distinct acceleration profiles on the neuromuscular efficiency, force, and power during concentric and eccentric phases of isoinertial squatting exercise. Design: Cross-sectional study. Setting: Biomechanics laboratory of the university. Participants: A total of 38 active adults were divided according to their acceleration profiles: higher (n = 17; >2.5 m/s2) and lower acceleration group (n = 21; <2.5 m/s2). Intervention: All subjects performed squats until failure attached to an isoinertial conic pulley device monitored by surface electromyography of rectus femoris, vastus medialis, vastus lateralis, biceps femoris, and semitendinosus. Main Outcome Measures: An incremental optical encoder was used to assess maximal and mean power and force during concentric and eccentric phases. The neuromuscular efficiency was calculated using the mean force and the electromyographic linear envelope. Results: Between-group differences were observed for the maximal and mean force (Prange = .001–.005), power (P = .001), and neuromuscular efficiency (Prange = .001–.03) with higher significant values for the higher acceleration group in both concentric and eccentric phases. Conclusion: Distinct acceleration profiles affect the neuromuscular efficiency, force, and power during concentric and eccentric phases of isoinertial squatting exercise. To ensure immediate higher levels of power and force output without depriving the neuromuscular system, acceleration profiles higher than 2.5 m/s2 are preferable. The acceleration profiles could be an alternative to evolve the isoinertial exercise.

scholarly journals Evaluation of Lower Limb Muscle Electromyographic Activity during 400 m Indoor Sprinting among Elite Female Athletes: A Cross-Sectional Study

2021 ◽  
Vol 18 (24) ◽  
pp. 13177
Author(s):  
Przemysław Pietraszewski ◽  
Artur Gołaś ◽  
Michał Krzysztofik ◽  
Marta Śrutwa ◽  
Adam Zając
Keyword(s):  
Lower Limb ◽  
Vastus Lateralis ◽  
Gluteus Maximus ◽  
Biceps Femoris ◽  
Cross Sectional Study ◽  
Sectional Study ◽  
Cross Sectional ◽  
Gastrocnemius Medialis ◽  
Lower Limb Muscles ◽  
Semg Signals

The purpose of this cross-sectional study was to analyze changes in normalized surface electromyography (sEMG) signals for the gastrocnemius medialis, biceps femoris, gluteus maximus, tibialis anterior, and vastus lateralis muscles occurring during a 400 m indoor sprint between subsequent curved sections of the track. Ten well-trained female sprinters (age: 21 ± 4 years; body mass: 47 ± 5 kg; body height: 161 ± 7 cm; 400 m personal best: 52.4 ± 1.1 s) performed an all-out 400 m indoor sprint. Normalized sEMG signals were recorded bilaterally from the selected lower limb muscles. The two-way ANOVA (curve × side) revealed no statistically significant interaction. However, the main effect analysis showed that normalized sEMG signals significantly increased in subsequent curves run for all the studied muscles: gastrocnemius medialis (p = 0.003), biceps femoris (p < 0.0001), gluteus maximus (p = 0.044), tibialis anterior (p = 0.001), and vastus lateralis (p = 0.023), but differences between limbs were significant only for the gastrocnemius medialis (p = 0.012). The results suggest that the normalized sEMG signals for the lower limb muscles increased in successive curves during the 400 m indoor sprint. Moreover, the gastrocnemius medialis of the inner leg is highly activated while running curves; therefore, it should be properly prepared for high demands, and attention should be paid to the possibility of the occurrence of a negative adaptation, such as asymmetries.

scholarly journals Evaluation of the Lower Limb Muscles’ Electromyographic Activity during the Leg Press Exercise and Its Variants: A Systematic Review

2020 ◽  
Vol 17 (13) ◽  
pp. 4626
Author(s):  
Isabel Martín-Fuentes ◽  
José M. Oliva-Lozano ◽  
José M. Muyor
Keyword(s):  
Muscle Activation ◽  
Vastus Lateralis ◽  
Muscular Activity ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Quadriceps Muscle ◽  
Electromyographic Activity ◽  
Full Extension ◽  
Cross Sectional ◽  
Leg Press

The aim of this study was to analyze the literature on muscle activation measured by surface electromyography (sEMG) of the muscles recruited when performing the leg press exercise and its variants. The Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed to report this review. The search was carried out using the PubMed, Scopus, and Web of Science electronic databases. The articles selected met the following inclusion criteria: (a) a cross-sectional or longitudinal study design; (b) neuromuscular activation assessed during the leg press exercise, or its variants; (c) muscle activation data collected using sEMG; and (d) study samples comprising healthy and trained participants. The main findings indicate that the leg press exercise elicited the greatest sEMG activity from the quadriceps muscle complex, which was shown to be greater as the knee flexion angle increased. In conclusion, (1) the vastus lateralis and vastus medialis elicited the greatest muscle activation during the leg press exercise, followed closely by the rectus femoris; (2) the biceps femoris and the gastrocnemius medialis showed greater muscular activity as the knee reached full extension, whereas the vastus lateralis and medialis, the rectus femoris, and the tibialis anterior showed a decreasing muscular activity pattern as the knee reached full extension; (3) evidence on the influence of kinematics modifications over sEMG during leg press variants is still not compelling as very few studies match their findings.

scholarly journals Sub-elite sprinters and rugby players possess different morphological characteristics of the individual hamstrings and quadriceps muscles

PLoS ONE ◽  
2021 ◽  
Vol 16 (10) ◽  
pp. e0259039
Author(s):  
Raki Kawama ◽  
Masamichi Okudaira ◽  
Tatsuya Shimasaki ◽  
Hirohiko Maemura ◽  
Satoru Tanigawa
Keyword(s):  
Vastus Lateralis ◽  
Morphological Characteristics ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Quadriceps Femoris ◽  
Cross Sectional ◽  
Vastus Intermedius ◽  
Morphological Differences ◽  
The Individual ◽  
Rugby Players

Numerous studies have clarified that sprinters possess unique morphological characteristics of the thigh muscles compared with non-athletes. However, little evidence is available regarding the morphological differences between sprinters and rugby players. This study aimed to examine the morphological differences in the individual hamstrings and quadriceps femoris muscles between sub-elite sprinters and rugby players. Ultrasound images were acquired from the proximal, middle, and distal regions of the thigh. From the images, the anatomical cross-sectional areas were calculated for 14 sub-elite sprinters, 14 rugby players, and 14 non-athletes. The calculated anatomical cross-sectional areas were normalized to two-thirds power of the body mass, and the normalized values of all regions were averaged as those of the individual muscles. In the hamstrings, the sizes of the biceps femoris short head and semitendinosus were greater in the sprinters than in the rugby players and/or non-athletes (all p < 0.05). In contrast, in the quadriceps femoris, the sizes of the rectus femoris, vastus lateralis, and vastus intermedius were the greatest in the rugby players (all p < 0.05). In the middle region of the biceps femoris short head and the proximal-middle regions of the semitendinosus, the muscle sizes were greater in the sprinters than in the rugby players (all p < 0.05), and vice versa in the middle-distal regions of the rectus femoris (all p < 0.05). These results suggest that 1) sub-elite sprinters possess larger sizes of the biceps femoris short head and semitendinosus, whereas rugby players have larger sizes of the rectus femoris, vastus lateralis, and vastus intermedius, and 2) each of the athletes has different size distributions, especially along the lengths of BFsh, ST, and RF. The findings of the present study would be helpful for rugby players in designing training regimens aimed at enhancing sprint performance.

What Determines The Migration Intentions Of University Students?

2014 ◽  
Vol 1 (1) ◽  
pp. 193-198
Author(s):  
Heiko Haase ◽  
Arndt Lautenschläger
Keyword(s):  
University Students ◽  
Career Choice ◽  
Cross Sectional Study ◽  
Demographic Characteristics ◽  
Migration Decision ◽  
Considerable Proportion ◽  
Sectional Study ◽  
Intention To Stay ◽  
Cross Sectional ◽  
The University

AbstractThe paper aims at exploring determinants of the university students' intentions to stay within their university region. At this, we presume that students' career choice motivations are related to their professional intentions, which again, along with demographic characteristics, affect their migration decision. Our analysis is based on a cross-sectional study of 2,353 students from three different higher education institutions, two of them located in Germany and one in Namibia. Results indicate that in Germany migration matters because a considerable proportion of students intend to leave the university region after graduation. At this, we found that the students' geographical provenance exerts the most significant effect on the intention to stay. Moreover, certain professional intentions were directly and some career choice motivations were indirectly linked with the intention to remain at the university location. We present several conclusions and implications.

Correlation of Glycemic Control Parameters in Non-Diabetic Persons with Cardiovascular Risk Scores - Results from a Cross- Sectional Study

2017 ◽  
Vol 68 (1) ◽  
pp. 108-110
Author(s):  
Gina Botnariu ◽  
Norina Forna ◽  
Alina Popa ◽  
Raluca Popescu ◽  
Alina Onofriescu ◽  
...  
Keyword(s):  
Cardiovascular Risk ◽  
Glycemic Control ◽  
Tolerance Test ◽  
Cross Sectional Study ◽  
Risk Scores ◽  
Oral Glucose ◽  
Cross Sectional ◽  
University Of Edinburgh ◽  
Fasting Glycaemia ◽  
The University

To assess the correlation between main parameters of glycemic control and cardiovascular risk scores in non-diabetic persons. Risk scores were calculated by using the University of Edinburgh Risk Calculator. Risk scores are used to estimate the probability of cardiovascular disease in individuals who have not already developed major atherosclerotic disease. We correlated the results of these scores with the parameters that describes the glycaemic profile: preprandial glicaemia, HbA1c and 1 hour and 2 h post-prandial glycaemia, determined during Oral Glucose Tolerance Test (OGTT).Both fasting glycaemia and HbA1c significantly correlated with cardiovascular risk scores calculated for a period of 10 years. The recorded post-prandial glycaemic values at 1h and 2h after glucose loading didn�t significantly correlate with calculated scores, in the study group. The observed correlations underline the importance of glycaemia in the pathogenesis of cardiovascular diseases.

scholarly journals Prevalence of SARS-CoV-2 Infection at the University of Barcelona during the Third COVID-19 Pandemic Wave in Spain

2021 ◽  
Vol 18 (12) ◽  
pp. 6526
Author(s):  
Sebastián Videla ◽  
Aurema Otero ◽  
Sara Martí ◽  
M. Ángeles Domínguez ◽  
Nuria Fabrellas ◽  
...  
Keyword(s):  
Ad Hoc ◽  
Venous Blood ◽  
Herd Immunity ◽  
Cross Sectional Study ◽  
Rt Pcr ◽  
Igg Antibody ◽  
Cross Sectional ◽  
Total Prevalence ◽  
The University ◽  
The Impact

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic started in December 2019 and still is a major global health challenge. Lockdown measures and social distancing sparked a global shift towards online learning, which deeply impacted universities’ daily life, and the University of Barcelona (UB) was not an exception. Accordingly, we aimed to determine the impact of the SARS-CoV-2 pandemic at the UB. To that end, we performed a cross-sectional study on a sample of 2784 UB members (n = 52,529). Participants answered a brief, ad hoc, online epidemiological questionnaire and provided a nasal swab for reverse transcription polymerase chain reaction (RT-PCR) SARS-CoV-2 analysis and a venous blood sample for SARS-CoV-2 IgG antibody assay. Total prevalence of SARS-CoV-2 infection (positive RT-PCR or positive IgG) was 14.9% (95%CI 13.3 to 17.0%). Forty-four participants (1.6%, 95%CI: 1.2–2.1%) were positive for SARS-CoV-2 RT-PCR. IgG against SARS-CoV-2 was observed in 12.8% (95%CI: 11.6–14.1%) of participants. Overall, while waiting for population vaccination and/or increased herd immunity, we should concentrate on identifying and isolating new cases and their contacts.

scholarly journals Visual Acuity’s Association With Levels of Leisure-Time Physical Activity in Community-Dwelling Older Adults

2012 ◽  
Vol 20 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Mark W. Swanson ◽  
Eric Bodner ◽  
Patricia Sawyer ◽  
Richard M. Allman
Keyword(s):  
Physical Activity ◽  
Older Adults ◽  
Visual Acuity ◽  
Leisure Time ◽  
Leisure Time Physical Activity ◽  
Cross Sectional Study ◽  
Community Dwelling ◽  
University Of Alabama ◽  
Cross Sectional ◽  
The University

Little is known about the effect of reduced vision on physical activity in older adults. This study evaluates the association of visual acuity level, self-reported vision, and ocular disease conditions with leisure-time physical activity and calculated caloric expenditure. A cross-sectional study of 911 subjects 65 yr and older from the University of Alabama at Birmingham Study of Aging (SOA) cohort was conducted evaluating the association of vision-related variables to weekly kilocalorie expenditure calculated from the 17-item Leisure Time Physical Activity Questionnaire. Ordinal logistic regression was used to evaluate possible associations while controlling for potential confounders. In multivariate analyses, each lower step in visual acuity below 20/50 was significantly associated with reduced odds of having a higher level of physical activity, OR 0.81, 95% CI 0.67, 0.97. Reduced visual acuity appears to be independently associated with lower levels of physical activity among community-dwelling adults.

scholarly journals Study protocol: content and perceived educational utility of different modalities of clinical teaching visit (CTV) workplace-based assessments within Australian general practice vocational training: a cross-sectional study

BMJ Open ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. e045643
Author(s):  
Alison Fielding ◽  
Benjamin Eric Mundy ◽  
Amanda Tapley ◽  
Linda Klein ◽  
Sarah Gani ◽  
...  
Keyword(s):  
General Practice ◽  
Clinical Teaching ◽  
Educational Practice ◽  
Cross Sectional Study ◽  
Practice Session ◽  
Cross Sectional ◽  
Human Research Ethics ◽  
General Practice Registrar ◽  
Australian General Practice ◽  
The University

IntroductionClinical teaching visits (CTVs) are formative workplace-based assessments that involve a senior general practitioner (GP) observing a clinical practice session of a general practice registrar (specialist vocational GP trainee). These visits constitute a key part of Australian GP training. Despite being mandatory and resource-intensive, there is a paucity of evidence regarding the content and educational utility of CTVs. This study aims to establish the content and educational utility of CTVs across varying practice settings within Australia, as perceived by registrars and their assessors (‘CT visitors’). In addition, this study aims to establish registrar, CT visitor and practice factors associated with CTV content and perceived CTV utility ratings.Methods and analysisThis study will collect data prospectively using online questionnaires completed soon after incident CTVs. Participants will be registrars and CT visitors of CTVs conducted from March 2020 to January 2021. The setting is three Regional Training Organisations across four Australian states and territories (encompassing 37% of Australian GP registrars).Outcome factors will be a number of specified CTV content elements occurring during the CTV as well as participants’ perceptions of CTV utility, which will be analysed using univariate and multivariable regression.Ethics and disseminationEthics approval has been granted by the University of Newcastle Human Research Ethics Committee, approval number H-2020-0037. Study findings are planned to be disseminated via conference presentation, peer-reviewed journals, educational practice translational workshops and the GP Synergy research subwebsite.

scholarly journals Insights into the Predictors of Attitude toward Entomophagy: The Potential Role of Health Literacy: A Cross-Sectional Study Conducted in a Sample of Students of the University of Florence

2021 ◽  
Vol 18 (10) ◽  
pp. 5306
Author(s):  
Chiara Lorini ◽  
Laura Ricotta ◽  
Virginia Vettori ◽  
Marco Del Riccio ◽  
Massimiliano Alberto Biamonte ◽  
...  
Keyword(s):  
Data Analysis ◽  
Health Literacy ◽  
Potential Role ◽  
Cross Sectional Study ◽  
Sectional Study ◽  
Cross Sectional ◽  
University Of Florence ◽  
The University ◽  
Self Administered Questionnaire

In Western countries, one of the main barriers to entomophagy is repulsion toward insects. Few studies have investigated the factors that influence attitudes toward entomophagy. Therefore, we conducted a cross-sectional study involving a sample of 248 university students, focusing on disgust and other potential attributes that can influence insect consumption, including health literacy. We used a 17-item self-administered questionnaire. Consistent with the literature, two items were chosen as outcome variables to evaluate the predictors of the propensity to consume insects: “Have you ever eaten insects or insect-based products?” and “How disgusting do you find eating insects?” The data analysis shows that having already eaten insects is inversely associated with the level of disgust (OR: 0.1, p < 0.01); and it is positively associated with higher levels of health literacy (OR: 3.66, p > 0.01). Additionally, having some knowledge and information about entomophagy is inversely associated with a higher level of disgust (OR: 0.44, p = 0.03 and OR: 0.25, p = 0.03, respectively), while being female is positively associated with disgust (OR: 3.26, p < 0.01). Our results suggest the potential role of health literacy, in addition to other factors, in influencing the willingness to taste insects. However, further studies involving larger and non-convenience samples are needed to confirm our hypothesis.

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