scholarly journals Factorial Structure of Trunk Motor Qualities and Their Association with Explosive Movement Performance in Young Footballers

Sports ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 67
Author(s):  
Jasminka Tomčić ◽  
Nejc Šarabon ◽  
Goran Marković
Keyword(s):  
Body Height ◽  
Principal Component ◽  
Trunk Muscle ◽  
Muscle Endurance ◽  
Football Players ◽  
Principal Component Factor Analysis ◽  
Factorial Structure ◽  
Jump Performance ◽  
Movement Performance ◽  
Trunk Strength

This study examined the factorial structure of trunk motor qualities and their associations with explosive muscular performance of football players. Ninety-one young male football players (age: 15–21 years; body height: 1.78 ± 0.07 m; body mass: 70.3 ± 7.5 kg) performed a series of tests: four standing and four seated isometric trunk strength tests, seven trunk power (medicine ball throwing) tests, four trunk endurance tests and four explosive movement performance tests. A principal component factor analysis (PCA) was used to determine the structure of trunk motor qualities, and correlational analyses were used to assess linear associations between trunk motor qualities and explosive performance. The PCA revealed four independent factors—trunk power, standing and seated isometric trunk strength, and trunk muscle endurance. Only trunk power had significant moderate, logically positive associations with sprint and vertical jump performance (common variance: 25–36%), while other associations between trunk motor factors and explosive movement performance were generally low to very low. These results indicate that trunk muscle functions of football players can be described with three independent motor qualities—trunk power, trunk strength and trunk muscle endurance, with only trunk power being moderately associated with players’ sprinting and jumping performance.

scholarly journals Physiological factors of importance for load carriage

2017 ◽  
Author(s):  
Manne Godhe ◽  
Torbjoern Helge ◽  
C. Mikael Mattsson ◽  
Oerjan Ekblom ◽  
Bjoern Ekblom
Keyword(s):  
Muscle Strength ◽  
Muscle Fibre ◽  
Body Mass ◽  
Body Height ◽  
Trunk Muscle ◽  
Muscle Endurance ◽  
Fibre Distribution ◽  
Load Carrying ◽  
Leg Muscle ◽  
Heavy Loads

The energy expenditure during carrying no load, 20, 35 and 50 kg at two walking speeds, 3 and 5 km/h, was studied in 36 healthy participants, 19 men (30 ± 6 yrs, 82.5 ± 7.0 kg) and 17 women (29 ± 6 yrs, 66.1 ± 8.9 kg). Anthropometric data, leg muscle strength as well as trunk muscle endurance and muscle fibre distribution of the thigh were also obtained. To load the participant a standard backpack filled with extra weight according to the carrying weight tested was used. Extra Load Index (ELI), the oxygen uptake (VO2) during total load over no-load-exercise, was used as a proxy for load carrying ability. In addition to analyzing factors of importance for the ELI values, we also conducted mediator analyzes using sex and long term carrying experience as causal variables for ELI as the outcome value. For the lowest load (20 kg), ELI20, was correlated with body mass but no other factors. Walking at 5 km/h body mass, body height, leg muscle strength and absolute VO2max were correlated to ELI35 and ELI50, but relative VO2max, trunk muscle endurance and leg muscle fibre distribution were not. Sex as causal factor was evaluated in a mediator analyses with ELI50 as outcome. ELI50 at 5 km/h differed between the sexes. The limit for acceptable body load, 40% of VO2max (according to Astrand, 1967), was nearly reached for women carrying 35 kg (39%) and surpassed at 50 kg at 3 km/h, and for men carrying 50 kg at 5 km/h. This difference was only mediated by difference in body mass. Neither muscle fibre distribution, leg muscle strength, trunk muscle endurance and body height nor did absolute or relative VO2max explain the difference. Participants with long term experience of heavy load carrying had significant lower ELI20 and ELI50 values than those with minor or non-experience, but none of the above studied factors could explain this difference. The study showed that body mass and experience of carrying heavy loads are important factors for the ability to carry heavy loads.

scholarly journals Principal component analysis of the conformation traits of Yankasa sheep

2013 ◽  
Vol 29 (1) ◽  
pp. 65-74 ◽  
Author(s):  
A. Yakubu
Keyword(s):  
Body Height ◽  
Age Groups ◽  
Principal Component ◽  
Tail Length ◽  
The Body ◽  
Head Width ◽  
Principal Component Factor Analysis ◽  
Body Measurements ◽  
Age Group ◽  
Leg Length

This study was preformed to evaluate the biometric traits of 227 Yankasa sheep in northern Nigeria under a multivariate approach. The body measurements taken were: withers height, rump height, body length, heart girth, tail length, face length, shoulder width, head width, rump width, ear length, foreleg length, hind leg length and rump length. The animals were divided into two age groups: <15.5 and 15.5 - 28.3 months old, respectively. General linear model was used to study age group effect while principal component factor analysis was performed to define body shape upon the correlation matrix of the thirteen body measurements. Age group significantly (P<0.05) affected the morphological characters except ear length. Pearson?s coefficients of correlation were positive and significant in both age groups. In <15.5 months old sheep, four principal components (factors) were extracted (ratio of variance = 89.27). The first factor accounted for 73.03% of the total variance and was interpreted as a measure of general size. The second factor which explained 7.61% of the generalized variance tended to describe flesh dimensions (shoulder width and rump width), while the third factor had its loadings for tail length and ear length. The fourth factor was influenced by head width. In 15.5-28.3 months old sheep, three factors (ratio of variance=75.21) were identified. These seven extracted factors could be considered in breeding programmes to improve body conformation of sheep since variation in meat traits was not associated with body height.

scholarly journals Effect of Various Warm-Up Protocols on Jump Performance in College Football Players

2012 ◽  
Vol 35 (1) ◽  
pp. 127-132 ◽  
Author(s):  
Jeffrey C. Pagaduan ◽  
Haris Pojskić ◽  
Edin Užičanin ◽  
Fuad Babajić
Keyword(s):  
Repeated Measures ◽  
Body Height ◽  
College Football ◽  
Football Players ◽  
Static Stretching ◽  
Countermovement Jump ◽  
Jump Performance ◽  
Warm Up ◽  
Dynamic Stretching ◽  
Post Hoc

The purpose of this study was to identify the effects of warm-up strategies on countermovement jump performance. Twenty-nine male college football players (age: 19.4 ± 1.1 years; body height: 179.0 ± 5.1 cm; body mass: 73.1 ± 8.0 kg; % body fat: 11.1 ± 2.7) from the Tuzla University underwent a control (no warm-up) and different warm-up conditions: 1. general warm-up; 2. general warm-up with dynamic stretching; 3. general warm-up, dynamic stretching and passive stretching; 4. passive static stretching; 5. passive static stretching and general warm-up; and, 6. passive static stretching, general warm-up and dynamic stretching. Countermovement jump performance was measured after each intervention or control. Results from one way repeated measures ANOVA revealed a significant difference on warm-up strategies at F (4.07, 113.86) = 69.56, p < 0.001, eta squared = 0.72. Bonferonni post hoc revealed that a general warm-up and a general warm-up with dynamic stretching posted the greatest gains among all interventions. On the other hand, no warm-up and passive static stretching displayed the least results in countermovement jump performance. In conclusion, countermovement jump performance preceded by a general warmup or a general warm-up with dynamic stretching posted superior gains in countermovement jump performance.

scholarly journals Physiological Factors of Importance for Load Carriage in Experienced and Inexperienced Men and Women

2020 ◽  
Vol 185 (7-8) ◽  
pp. e1168-e1174
Author(s):  
Manne Godhe ◽  
Torbjörn Helge ◽  
C Mikael Mattsson ◽  
Örjan Ekblom ◽  
Björn Ekblom
Keyword(s):  
Muscle Strength ◽  
Body Mass ◽  
Muscle Fiber ◽  
Body Height ◽  
Trunk Muscle ◽  
Muscle Endurance ◽  
Fiber Distribution ◽  
Load Carrying ◽  
Leg Muscle ◽  
Heavy Loads

Abstract Introduction The ability to carry heavy loads is an important and necessary task during numerous outdoor activities and especially in military operations. The aim of this study was to investigate factors associated with load-carrying ability in men and women with and without extensive load-carrying experience. Materials and Methods The energy expenditure during carrying no load, 20, 35, and 50 kg at 2 walking speeds, 3 and 5 km h−1, was studied in 36 healthy participants, 19 men (30 ± 6 years, 82.5 ± 7.0 kg) and 17 women (29 ± 6 years, 66.1 ± 8.9 kg), experienced (&gt;5 years) in carrying heavy loads (n = 16, 8 women) or with minor or no such experience (n = 20, 9 women). A standard backpack filled with weights to according carry load was used during the walks. Anthropometric data, leg muscle strength, as well as trunk muscle endurance and muscle fiber distribution of the thigh, were also obtained. Extra Load Index (ELI)—the oxygen uptake (VO2) during total load over unloaded walking—was used as a proxy for load-carrying ability at 20, 35, and 50 kg (ELI20, ELI35, and ELI50, respectively). In addition to analyzing factors of importance for the ELI values, we also conducted mediator analyses using sex and long-term carrying experience as causal variables for ELI as the outcome value. The study was approved by the Regional Ethics Committee in Stockholm, Sweden. Results For the lowest load (20 kg), ELI20, was correlated with body mass but no other factors. Walking with 35 and 50 kg load at 5 km h−1 body mass, body height, leg muscle strength, and absolute VO2max were correlated, while relative VO2max, trunk muscle endurance, and leg muscle fiber distribution were not correlated to ELI35 and ELI50. ELI50 at 5 km h−1 differed between the sexes. This difference was only mediated by the difference in body mass. Neither muscle fiber distribution, leg muscle strength, trunk muscle endurance, and body height nor did absolute or relative VO2max explain the difference. Participants with long-term experience of heavy load carrying had significant lower ELI20 and ELI50 values than those with minor or no experience, but none of the above studied factors could explain this difference. Conclusion The study showed that body mass, without sex differences, and experience of carrying heavy loads are the dominant factors for the ability to carry heavy loads. Even though the effect of experience alludes to the need for extensive carrying training, no causality can be proven. Load carry training intervention studies is suggested for future investigations.

Trunk muscle endurance, strength and flexibility in rural subsistence farmers and urban industrialized adults in western Kenya

2021 ◽  
Author(s):  
Benjamin E. Sibson ◽  
Victoria A. Tobolsky ◽  
Timothy M. Kistner ◽  
Nicholas B. Holowka ◽  
Josphine Jemutai ◽  
...  
Keyword(s):  
Trunk Muscle ◽  
Muscle Endurance ◽  
Subsistence Farmers ◽  
Western Kenya ◽  
Endurance Strength

Use of the Perceived Physical Competence Scale with Adolescents with Disabilities

1995 ◽  
Vol 80 (2) ◽  
pp. 571-577 ◽  
Author(s):  
Taru Lintunen ◽  
Pilvikki Heikinaro-Johansson ◽  
Claudine Sherrill
Keyword(s):  
Gender Differences ◽  
Factor Analysis ◽  
Principal Component ◽  
Principal Component Factor Analysis ◽  
Validity And Reliability ◽  
Varimax Rotation ◽  
Physical Competence ◽  
Related Literature ◽  
Competence Scale ◽  
Two Factors

The construct validity and reliability of the 1987 Perceived Physical Competence Scale of Lintunen were examined to assess the applicability of the instrument for use with adolescents with disabilities. Subjects were 51 girls and 34 boys ( M age = 15.1 yr.) from several schools in central Finland. Principal component factor analysis with varimax rotation yielded the same two factors for adolescents with disabilities as reported for nondisabled adolescents in the related literature. Cronbach alphas for the two factors were .89 and .56. It was concluded that the scale is an appropriate measure for adolescents with disabilities. Statistical analysis indicated no gender differences for adolescents with disabilities. When compared with nondisabled groups in the related literature, these adolescents had perceived fitness similar to nondisabled peers but significantly lower than that of athletes without disabilities.

Developing the Organisational Justice Scale and Examining Teachers' and School Administrators' Views about Organisational Justice in Primary Schools

2021 ◽  
pp. 33-50
Author(s):  
Hasan Basri Memduhoðlu ◽  
Ali Ýhsan Yildiz
Keyword(s):  
Factor Analysis ◽  
Primary Schools ◽  
School Administrators ◽  
Data Gathering ◽  
Principal Component ◽  
Measurement Tool ◽  
Principal Component Factor Analysis ◽  
Reliable Measurement ◽  
Organisational Justice ◽  
Confirmatory Factor

The purpose of this study is to develop a reliable and valid measurement tool to explore views about organisational justice in schools and to examine teachers' and school administrators' views about organisational justice in primary schools. The sample of the study consisted of a total of 455 participants, 176 school administrators and 279 teachers from the primary schools in the Centre of Van. The Organisational Justice Scale, developed by the authors, was employed as data gathering tool. Principal Component Factor Analysis was used to determine the content and construct validities of the scale and Confirmatory Factor Analysis was employed to evaluate the obtained results. As a result of the study, the developed Organisational Justice Scale (OJS) was found to be a valid and reliable measurement tool for school applications.

scholarly journals Stigma as a barrier to family planning use among married youth in Ethiopia

2018 ◽  
Vol 51 (4) ◽  
pp. 505-519
Author(s):  
Aparna Jain ◽  
Hussein Ismail ◽  
Elizabeth Tobey ◽  
Annabel Erulkar
Keyword(s):  
Family Planning ◽  
Supply And Demand ◽  
Unmet Need ◽  
Principal Component ◽  
Principal Component Factor Analysis ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Adolescent Groups ◽  
Anticipated Stigma ◽  
Youth Friendly Service

AbstractNearly 33 million female youths have an unmet need for voluntary family planning (FP), meaning they are sexually active and do not want to become pregnant. In Ethiopia, age at marriage remains low: 40% and 14% of young women aged 20–24 were married by the ages of 18 and 15, respectively. Despite increases in FP use by married 15- to 24-year-olds from 5% in 2000 to 37% in 2016, unmet need remains high at 19%. Supply-and-demand factors have been shown to limit FP use, yet little is known about how stigma influences FP use among youth. This study validates an anticipated stigma (expectation of discrimination from others) index and explores its effect on unmet need. A cross-sectional survey was implemented with 15- to 24-year-old female youth in Ethiopia in 2016. The analytic sample included married respondents with a demand (met and unmet need) for FP (n=371). A five-item anticipated stigma index (Cronbach’sα=0.66) was developed using principal component factor analysis. These items related to fear, worry and embarrassment when accessing FP. The findings showed that 30% agreed with at least one anticipated stigma question; 44% had an unmet need; 58% were married before age 18; and 100% could name an FP method and knew where to obtain FP. In multivariate regression models, youth who experienced anticipated stigma were significantly more likely to have an unmet need, and those who lived close to a youth-friendly service (YFS) site were significantly less likely to have an unmet need. Interventions should address anticipated stigma while focusing on social norms that restrict married youth from accessing FP; unmet need may be mitigated in the presence of a YFS; and the anticipated stigma index appears valid and reliable but should be tested in other countries and among different adolescent groups.

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