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Arm/Shoulder Specific Strength Device for Throwers
Brahim Agrebi,
Rachid Bouagina,
Akram Fray,
Hatem Abidi,
Fethi Guemira,
Mounir Bezzarga,
Nooman Guelmami,
Narjes Houas,
Sofien Kasmi,
Oussama Ben Mohamed,
Riadh Khalifa
Issue:
Volume 8, Issue 1, March 2020
Pages:
1-9
Received:
8 January 2020
Accepted:
20 January 2020
Published:
4 February 2020
Abstract: Research has proposed various ways to develop ballistic/explosive arm rotational movements for throwers but demonstrated inherent limitations for the lack of traditional resistance training respecting sport-specific tasks. A prototype device was conceived for ballistic multi-joint throwing exercises. Forty-three high-level competitive U19 male handball players participated in the study aged 18.42 ± 1.17 years; 82.36 ± 3.07 mass kg; and 184.91 ± 6.06 m height. Subjects underwent tests on the ASSSD, which operates into consecutive accelerative and decelerative actions, for throwing characteristics determination. Concentric (CON) and eccentric (ECC) variables during overhead throws as force, power, velocity, acceleration and angle when occurred peak force (PF), power (PP) and velocity (PV) were defined. The relative reliability was calculated using the intraclass correlation coefficients (ICCs) showing strong agreement between trials. The absolute reliability was analyzed using standard error of measurement SEM (0.03-2.75), and Coefficients of variation CVs (2.84-4.59%) for studied variables, reveals excellent interday reliability. Validity was assessed using linear regressions, r and p values showing good relationship between PF and PP gathered from ASSSD and isokinetic peak torques at different angular velocities of dominant arm (DA). The device sensitivity was verified when assessing CON-ECC PF, CON-ECC PP and CON PV with elite/non-elite players. The ASSSD has demonstrated its reliability, validity and sensitivity intended for testing, training monitoring and sport performance assessment.
Abstract: Research has proposed various ways to develop ballistic/explosive arm rotational movements for throwers but demonstrated inherent limitations for the lack of traditional resistance training respecting sport-specific tasks. A prototype device was conceived for ballistic multi-joint throwing exercises. Forty-three high-level competitive U19 male hand...
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Composition of Change in Phase Angle with Age in Japanese Children
Katsunori Fujii,
Kentaro Hayakawa
Issue:
Volume 8, Issue 1, March 2020
Pages:
10-16
Received:
17 February 2020
Accepted:
26 February 2020
Published:
10 March 2020
Abstract: Phase angle (PhA) is a value derived from the resistance (R) in intra- and extracellular fluid and the reactance (Xc) in the cell membrane, measured by bioelectrical impedance analysis (BIA). It has also been referred to as a nutritional index that shows the level of cellular activation, becoming a focus of attention in recent years. However, very little is known about the changes in phase angle with age, particularly the changes that occur during the school-age years. In this study, we investigated whether phase angle has a maximum peak velocity (MPV) similar to that of physique, and if a pubertal peak exists whether it is meaningful as a biological parameter in the same way as height growth. The results showed that the age at MPV of phase angle may be proposed as a critical point in the acquisition of health with stronger physical growth and development during the school-age years. Assuming that MPV of phase angle is a critical point in physical growth and development, its involvement in disease needs to be closely observed with this critical point as a juncture since this is also a time period when the thymus of the immune system shows a pubertal peak. At the same time, beyond the pubertal peak of physique, this may be considered a period during which more adult-like physical enhancement and level of health is maintained.
Abstract: Phase angle (PhA) is a value derived from the resistance (R) in intra- and extracellular fluid and the reactance (Xc) in the cell membrane, measured by bioelectrical impedance analysis (BIA). It has also been referred to as a nutritional index that shows the level of cellular activation, becoming a focus of attention in recent years. However, very ...
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Myocardial Strain Imaging in Asian Competitive Athletes – A Single Centre Study
Yann Shan Keh,
Puay Joo Tan,
Siang Chew Chai,
Benedict Tan,
Khim Leng Tong
Issue:
Volume 8, Issue 1, March 2020
Pages:
17-21
Received:
24 January 2020
Accepted:
9 March 2020
Published:
23 March 2020
Abstract: To date there has been limited literature pertaining to Athlete’s Heart Syndrome in Asian athletes, especially for those in South East Asia. We performed a single center cross-sectional case-control study of elite athletes and controls, using current speckle-tracking echocardiography (STE) and tissue Doppler imaging (TDI)-based techniques. We reanalyzed previous data to further characterize the biomechanical changes in exercise induced cardiac remodeling elite athletes and controls at a tertiary hospital in Singapore. The Left Ventricular (LV) strain of the athletes’ group was significantly lower as compared to the control group (-19.0±2.0 vs -20.3±1.8, p=0.011). Furthermore, both LV torsion (14.3±17.8°/s vs 14.4±6.7°/s, p=0.031) and Lateral S’ (7.21±1.4 vs 8.7±1.6, p=0.001) showed small but statistically significant decreases in the athletes’ group versus the controls. The athletes group demonstrated a significantly lower Basal Right Ventricular (RV) free wall strain as compared to the controls (-19.8±5.5 vs -26.5±6.4 P < 0.001). The mid RV strain was marginally higher in the athletes’ group versus the controls (-25.0±4.3 vs -24.7±15.3 P=0.023). Our findings of impaired LV strain and torsion as well basal RV free walls strain in the South East Asian athletes group mirror studies done in Western cohorts. The higher mid RV free wall strain could represent compensatory response to the impaired basal RV function in athletes.
Abstract: To date there has been limited literature pertaining to Athlete’s Heart Syndrome in Asian athletes, especially for those in South East Asia. We performed a single center cross-sectional case-control study of elite athletes and controls, using current speckle-tracking echocardiography (STE) and tissue Doppler imaging (TDI)-based techniques. We reana...
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Kinematic Analysis of Support Phase Characteristics in Women Race Walking
Issue:
Volume 8, Issue 1, March 2020
Pages:
22-28
Received:
14 March 2020
Accepted:
27 March 2020
Published:
13 April 2020
Abstract: Race walking requires a great deal of effort to compete successfully which includes a unique combination of technique, extreme physical exertion and mental focus. Unlike running, race walking is composed by support phase (heel strike, mid-stance and toe off) and swing phase. The aim of this study was to analyze the association between different kinematic characteristics of support phase during race walking and walking velocity. The rules of race walking demand that no visible flight time should occur and the stance leg must be straightened from initial contact to midstance. Previous research has not examined whether these rules also have an effect on walking performance and what consequences might arise. Top ten (U-20 Girls) finishers of 10000m race walk discipline, 33rd National Junior Athletic Championships, 2017 held at Acharya Nagarjuna University, Vijaywada, A. P. India were recorded by using two Nikon digital 4K camcorders (60 Hz) mounted on rigid tripods were placed alongside of the course at approximately 90° to the plane of motion. The junior athletes were analyzed by using motion analysis software (KINOVEA 0.8.27). Descriptive statistics and Pearson Product Moment Correlation coefficient (p<0.05) were employed for statistical calculation. The tabulation of data was done by using the IBM SPSS 25 software. The result of the study revealed that, women athlete’s performance were affected by the long contact phase duration (Mean=0.33 s (±) 0.05). This factor relativity creates hindrances in propulsive phase. A negative association (r= -0.49) found between contact time and average speed. As expected, due to the technical rules of this discipline knee angel at heel contact is significantly correlated with velocity as the calculated r value was 0.709* (Critical value at 8 df r = 0.632). Whereas, at mid stance phase a negative correlation found between knee angle and walking performance that sketch a hyper extended knee. However, a positive linear relationship found in variables like, hip angle, elbow angle at heel contact and mid stance phase with walking velocity. But, a less economical technique observed in toe off phase for almost every variable as those were negatively associated with mean speed, and so a balance between those fundamental techniques of support phase variables is advisable. The race walkers had shorter swing times, longer contact times, and smaller maximum knee flexion angles (152° ± 7.32) than the distance runners. The smaller knee flexion angles in race walkers meant they experienced greater swing leg moment of inertia than the distance runners.
Abstract: Race walking requires a great deal of effort to compete successfully which includes a unique combination of technique, extreme physical exertion and mental focus. Unlike running, race walking is composed by support phase (heel strike, mid-stance and toe off) and swing phase. The aim of this study was to analyze the association between different kin...
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