scholarly journals Study on the Kinematic characteristics of different level jumpers squatting and jumping under different ground

2021 ◽  
Author(s):  
Hewen Hua
Keyword(s):  
Angular Velocity ◽  
Ankle Joint ◽  
High Speed ◽  
Angular Displacement ◽  
Group Analysis ◽  
Great Influence ◽  
Force Platform ◽  
Elastic Coefficient ◽  
Significant Difference ◽  
Different Levels

Abstract Objective: The purpose of this study is to compare the kinematic differences of different level jumping athletes in the process of squatting on different ground, and to reveal the biomechanical mechanism of the effect of squatting on different ground on training effect. Methods: The subjects were 11 first-class and above jumping athletes (excellent group) and 11 second-class athletes (ordinary group). The kinematic data were photographed by SONYDCRHC52E high-speed camera with a sampling frequency of 50 frames per second, and the data were analyzed by SIMI-Motion three-dimensional motion analysis system. The subjects squatted and jumped on four kinds of ground (force platform, balance pad, gymnastics pad and sand) with their hands on their hips. Results: In the intra-group analysis, it was found that the athletes of different levels squatted and jumped on four different kinds of ground, but there was no significant difference only on the balance pad and gymnastics mat (excellent group p=0.344, ordinary group p=1). In the inter-group analysis, it was found that there were significant differences between different levels of athletes in balance pad (p=0.043) and sand (p=0.02). In the buffering stage of squatting jump, there was no significant difference in the buffering angle displacement of lower limb joints of different athletes on different ground. In the stage of pedal and extension, the angular displacement of ankle on the middle platform of the excellent group was significantly different from that of the balance pad (p=0.014), gymnastics pad (p=0.017) and sand (p=0.013), but in the ordinary group, the ankle angular displacement of the middle platform was only significantly different from that of the gymnastics pad (p= 0.048) and sand (p=0.017), but not significantly different from that of the balance pad (p=0.166). The maximum angular velocity of hip joint of athletes of different levels was significantly different among different ground groups. The maximum angular velocity of ankle joint of common group was significantly different in force platform and sand (p=0.032), gymnastics mat and sand (p=0.008), but there was no significant difference in balance pad. Conclusion: Different places have great influence on the ordinary group, and on the ground with lower elastic coefficient, the maximum angular velocity of the ankle joint in the ordinary group is much smaller than that in the excellent group, which indicates that the rapid contractile ability of ankle muscles in the ordinary group is poor on the ground with low elastic coefficient. When squatting and jumping on the ground with lower elastic coefficient, the excellent group has better body control and coordination and lower joint energy loss, which makes the jumping effect better,

scholarly journals Study on the Kinematic characteristics of different level jumpers squatting and jumping under different ground

2021 ◽  
Author(s):  
Hua Hewen
Keyword(s):  
Angular Velocity ◽  
Ankle Joint ◽  
High Speed ◽  
Angular Displacement ◽  
Group Analysis ◽  
Great Influence ◽  
Force Platform ◽  
Elastic Coefficient ◽  
Significant Difference ◽  
Different Levels

Abstract Objective: The purpose of this study is to compare the kinematic differences of different level jumping athletes in the process of squatting on different ground, and to reveal the biomechanical mechanism of the effect of squatting on different ground on training effect.Methods: The subjects were 11 first-class and above jumping athletes (excellent group) and 11 second-class athletes (ordinary group). The kinematic data were photographed by SONYDCRHC52E high-speed camera with a sampling frequency of 50 frames per second, and the data were analyzed by SIMI-Motion three-dimensional motion analysis system. The subjects squatted and jumped on four kinds of ground (force platform, balance pad, gymnastics pad and sand) with their hands on their hips.Results: In the intra-group analysis, it was found that the athletes of different levels squatted and jumped on four different kinds of ground, but there was no significant difference only on the balance pad and gymnastics mat (excellent group p=0.344, ordinary group p=1). In the inter-group analysis, it was found that there were significant differences between different levels of athletes in balance pad (p=0.043) and sand (p=0.02). In the buffering stage of squatting jump, there was no significant difference in the buffering angle displacement of lower limb joints of different athletes on different ground. In the stage of pedal and extension, the angular displacement of ankle on the middle platform of the excellent group was significantly different from that of the balance pad (p=0.014), gymnastics pad (p=0.017) and sand (p=0.013), but in the ordinary group, the ankle angular displacement of the middle platform was only significantly different from that of the gymnastics pad (p= 0.048) and sand (p=0.017), but not significantly different from that of the balance pad (p=0.166). The maximum angular velocity of hip joint of athletes of different levels was significantly different among different ground groups. The maximum angular velocity of ankle joint of common group was significantly different in force platform and sand (p=0.032), gymnastics mat and sand (p=0.008), but there was no significant difference in balance pad.Conclusion: Different places have great influence on the ordinary group, and on the ground with lower elastic coefficient, the maximum angular velocity of the ankle joint in the ordinary group is much smaller than that in the excellent group, which indicates that the rapid contractile ability of ankle muscles in the ordinary group is poor on the ground with low elastic coefficient. When squatting and jumping on the ground with lower elastic coefficient, the excellent group has better body control and coordination and lower joint energy loss, which makes the jumping effect better, while the ordinary group squats and jumps on the ground with low elastic coefficient and unstable ground. the jumping effect is poor.

scholarly journals Study on the Kinematic characteristics of different level jumpers squatting and jumping under different ground

2021 ◽  
Author(s):  
Hua Hewehn
Keyword(s):  
Angular Velocity ◽  
Ankle Joint ◽  
High Speed ◽  
Angular Displacement ◽  
Group Analysis ◽  
Great Influence ◽  
Force Platform ◽  
Elastic Coefficient ◽  
Significant Difference ◽  
Different Levels

Abstract Objective: The purpose of this study is to compare the kinematic differences of different level jumping athletes in the process of squatting on different ground, and to reveal the photomechanical mechanism of the effect of squatting on the different ground on training effect.Methods: The subjects were 11 first-class and above jumping athletes (excellent group) and 11 second-class athletes (ordinary group). The kinematic data were photographed by SONYDCRHC52E high-speed camera with a sampling frequency of 50 frames per second, and the data were analyzed by SIMI-Motion three-dimensional motion analysis system. Subjects squatted and jumped on four kinds of ground (force platform, balance pad, gymnastics pad, and sand) with their hands on their hips.Results: In the intra-group analysis, it was found that the athletes of different levels squatted and jumped on four different kinds of ground, but there was no significant difference only on the balance pad and gymnastics mat (excellent group p=0.344, ordinary group p=1). In the inter-group analysis, it was found that there were significant differences between different levels of athletes in balance pad (p=0.043) and sand (p=0.02). In the buffering stage of the squatting jump, there was no significant difference in the buffering angle displacement of lower limb joints of different athletes on different ground. In the stage of pedal and extension, the angular displacement of the ankle on the middle platform of the excellent group was significantly different from that of the balance pad (p=0.014), gymnastics pad (p=0.017), and sand (p=0.013), but in the ordinary group, the ankle angular displacement of the middle platform was only significantly different from that of the gymnastics pad (p= 0.048) and sand (p=0.017), but not significantly different from that of the balance pad (p=0.166). The maximum angular velocity of the hip joint of athletes of different levels was significantly different among different ground groups. The maximum angular velocity of the ankle joint of the common group was significantly different in force platform and sand (p=0.032), gymnastics ma,t and sand (p=0.008), but there was no significant difference in balance pad.Conclusion: Different places have a great influence on the ordinary group, and on the ground with lower elastic coefficient, the maximum angular velocity of the ankle joint in the ordinary group is much smaller than that in the excellent group, which indicates that the rapid contractile ability of ankle muscles in the ordinary group is poor on the ground with low elastic coefficient. When squatting and jumping on the ground with a lower elastic coefficient, the excellent group has better body control and coordination and lower joint energy loss, which makes the jumping effect better, while the ordinary group squats and jumps on the ground with a low elastic coefficient and unstable ground. The jumping effect is poor.

scholarly journals Peculiarities of the chest’s size in female volleyball players of different constitutional types

2018 ◽  
pp. 47-52
Author(s):  
L. A. Sarafyniuk ◽  
V. I. Pivtorak ◽  
V. O. Khavtur ◽  
L. Ia. Fedoniuk ◽  
O. P. Khapitska
Keyword(s):  
Young Women ◽  
Great Influence ◽  
Control Group ◽  
Constitutional Type ◽  
Significant Difference ◽  
Volleyball Players ◽  
High Level ◽  
Medical University ◽  
Different Levels ◽  
Anterior Posterior

During qualified sport selection special attention should be paid to those features and abilities that have a great influence on the effectiveness, and those, that are mainly under the influence of genetic factor. Such morphogenetic markers of sports selection include, firstly, the constitutional features of athletes, in particular the shape of the chest. The purpose of work is to determine the differences between the anthropometric dimensions of the chest between female volleyball players of high level of athletic skill and non-sportsmen, who belonged to different constitutional types. On the base of the Scientific-Research Center of the Vinnytsya National Pirogov Memorial Medical University an anthropo-somatotypological investigation of 113 female volleyball players of high level athletic skill (from 16 to 20 years old) was done. The control group included 204 practically healthy young women, who were not engaged in sports of the corresponding age. Anthropometric research was performed according to the V. V. Bunak (1941) method, somatotypological study was based on the estimated modification of the Heath-Carter method (1990). In young women, who were not engaged in sports, more than in half of the cases were indicated constitutional types, which were characterized by good development of fatty body composition. Between female volleyball players were dominated individuals with mesomorphic somatotype (26.66%), ectomorphic somatotype (23.01%), ecto-mesomorphic somatotype (23.89%), and representatives of the intermediate somatotype (23.01%) were almost uniformly represented in the sample. The analysis of the results was carried out in the licensing program "Statistica 5.5" using nonparametric methods of estimating the parameters. We have found that the female volleyball players of the ectomorphic somatotype have the smallest anthropometric dimensions of the chest, as compared with athletes of other constitutional groups. In the mesomorphs female volleyball players all transverse and the most of overall sizes of the chest were the largest. Parameters of the athletes with the ecto-mesomorphic somatotype were slightly small to the size of the somatometric parameters of the mesomorphs, but they had the highest values of the anterior-posterior size of the chest. Female volleyball players with intermediate somatotype had larger values of the chest size than volleyball players with ectomorphic somatotype, although no significant difference was found when comparing them. It was found, that the most of the overall, transverse, and anterior-posterior dimensions of the chest in female volleyball players are statistically significantly higher than that of girls, who were not engaged in sports, and belonged to the same constitutional type as athletes. We have made a conclusion that belonging to one of the constitutional type does not provide similarity of morphometric parameters of the chest in persons with different levels of physical activity.

scholarly journals Kinematic Comparison on Lower Limb Kicking Action of Fetuses in Different Gestational Weeks: A Pilot Study

Healthcare ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1057
Author(s):  
Hairong Chen ◽  
Yang Song ◽  
Rongrong Xuan ◽  
Qiuli Hu ◽  
Julien S. Baker ◽  
...  
Keyword(s):  
Angular Velocity ◽  
Knee Joint ◽  
Ankle Joint ◽  
Lower Limb ◽  
Peak Level ◽  
Musculoskeletal Development ◽  
Kinematic Characteristics ◽  
Significant Difference ◽  
Fetal Movements ◽  
The Mean

The fetal movements during different gestational weeks are essential for normal musculoskeletal development. The kinematic characteristics of fetuses with small differences in gestational weeks may be different and important. Ultrasonographic videos of fetal kicking action and plantarflexion action were collected from three healthy pregnant women (24, 27, and 30 gestational weeks) with normal fetal development. The kinematic characteristics, including angular range and angular velocity, were analyzed. These kinematic parameters were measured using simi motion. The final knee angle was found to decrease with progressive gestational weeks. Compared with 24 w, the knee joint angle at 27 w and 30 w was significantly reduced at the end of a kick-type movement (p < 0.01). Except for the mean angular velocity of the knee joint, there were no significant differences in the other conditions. The value at 30 w for mean angular velocity was significantly higher than that at 24 w (p = 0.02). In the ankle joint, no significant differences were observed between different conditions. Therefore, we can conclude that there was no significant difference in the kinematic characteristics of the ankle joint for small gestational age gaps, but there was a significant difference in the knee joint. As the gestation weeks increase, the range of kicking motion tends to decrease. The reason may be that with the increase of gestational weeks, fetal lower limb musculoskeletal development is gradually enhanced; the slower growth rate indicates that development reaches a peak level in weeks 24 to 30.

scholarly journals Instant velocity and consistency of emitted cloud change by the different levels of canister filling with Metered Dose Inhalers (MDIs), but not with Soft Mist Inhalers (SMIs): a bench study

2017 ◽  
Vol 12 ◽  
Author(s):  
Roberto W. Dal Negro ◽  
Pietro Longo ◽  
Orestepaolo Villanis Ziani ◽  
Luca Bonadiman ◽  
Paola Turco
Keyword(s):  
High Speed ◽  
Real Life ◽  
Metered Dose Inhalers ◽  
Salbutamol Sulphate ◽  
Significance Level ◽  
Significant Difference ◽  
Metered Dose ◽  
Dose Fraction ◽  
Different Levels ◽  
Formoterol Fumarate

Background: Inhalation is the preferred route for respiratory drug delivery, but several factors contribute to the variability of the respirable dose fraction. Instant velocity and the dynamic characteristics of the droplet cloud represent crucial factors. Aim was to measure and compare the instant velocity and the consistency of emitted cloud from five different MDIs (A - Salbutamol sulphate 100mcg, GSK; B - Salbutamol sulphate 100mcg, Valeas; C - Salmeterol xinafoate/Fluticasone propionate 25/125mcg, GSK; D - Formoterol fumarate/Bechlomethasone propionate 6/100mcg, Chiesi; E - Formoterol fumarate/Fluticasone dipropionate 5/125mcg, Mundipharma) and one SMI (Tiotropium bromide 5mcg, Boehringer Ingelheim), at different distance from the nozzle and canister filling. Methods: Measurements were made at 90, 50, and 10% of canister filling, and at 5, 10, and 20 cm from the nozzle, for a total of 972 puffs. A high speed video photography protocol was adopted and high speed cameras (1.200 frames/ sec.) were used. Data were acquired by means of specialized softwares. Temperature, humidity, and vibrations occurrence were strictly controlled during measurements. Statistics: Anova and p < 0.05 were accepted as the minimum significance level. Results: MDIs generated different Instant velocities: MDI B generated the highest, while MDI A the lowest. As expected, velocity decreased in proportion to the distance from the nozzle. Except with MDI C, instant velocity decreased significantly over the first 50% of canister emptying, but dropped by >33% at 90% of emptying with all other MDIs (p < 0–037; p < 0.001; p < 0.005, and p < 0.001, respectively). Instant velocity was extremely lower (p < 0.001) and constant for all levels of canister filling (p = ns) with SMI. All MDIs had a very fast jet phase, ranging 0.01–0.03 s at 10 cm, and 0.03–0.05 s at 20 cm from the nozzle, without any significant difference from each other (p= ns). MDIs generated a cloud similarly tight (p = ns) at 10 and 20 cm from the nozzle, while it was extremely wider and constant with the SMI (p = 0–001). Also the cloud turbulence was minimized during the SMI emission. Discussion and Conclusions: MDIs are characterized by a substantial variability in both their instant velocity and consistency of the emitted cloud at different levels of canister filling. SMI generates a much slower soft mist cloud which is constantly homogeneous and independent of canister emptying. These peculiarities assessed at bench are suggesting a higher dose consistency and a much more effective therapeutic performance also in real life.

Attitudes toward the use of TELL tools in English language learning among Vietnamese Tertiary English majors

2019 ◽  
Vol 5 (5) ◽  
pp. 581-596
Keyword(s):  
Language Learning ◽  
Language Proficiency ◽  
English Language ◽  
English Language Learning ◽  
Guided Learning ◽  
Positive Attitudes ◽  
Significant Difference ◽  
English Majors ◽  
Very High ◽  
Different Levels

Technology plays a crucial role in the self-guided learning of a second language in general and English in particular. Nevertheless, many students in different contexts still ignore the application of technology-enhanced language learning (TELL) tools in enhancing their foreign language proficiency. Therefore, this study is conducted to investigate the attitudes towards the use of TELL tools in English-language learning (ELL) among English majors at one university in Vietnam. To collect data, 197 English majors participated in finishing the questionnaire, and 20 students were invited to join the interviews. The findings are that the majority of students have positive attitudes towards the use of TELL tools and the frequency of using these tools is very high. In addition, the results also reveal that there is no significant difference in attitudes towards and frequency of using TELL tools in learning English in terms of the year of study. However, students of different levels of academic achievements have different attitudes towards using TELL tools and use TELL tools to learn English differently. Received 2nd May 2019; Revised 16th July 2019, Accepted 20th October 2019

OVARIAN ASCORBIC ACID DEPLETION TEST FOR LUTEINIZING HORMONE

1967 ◽  
Vol 56 (4) ◽  
pp. 619-625 ◽  
Author(s):  
Hans Jacob Koed ◽  
Christian Hamburger
Keyword(s):  
Ascorbic Acid ◽  
Luteinizing Hormone ◽  
Dose Response ◽  
Response Curve ◽  
Dose Response Curve ◽  
Human Origin ◽  
Response Curves ◽  
Significant Difference ◽  
The Mean ◽  
Different Levels

ABSTRACT Comparison of the dose-response curves for LH of ovine origin (NIH-LH-S8) and of human origin (IRP-HMG-2) using the OAAD test showed a small, though statistically significant difference, the dose-response curve for LH of human origin being a little flatter. Two standard curves for ovine LH obtained with 14 months' interval, were parallel but at different levels of ovarian ascorbic acid. When the mean ascorbic acid depletions were calculated as percentages of the control levels, the two curves for NIH-LH-S8 were identical. The use of standards of human origin in the OAAD test for LH activity of human preparations is recommended.

The Effectiveness of Using a Mobile Messenger as an Educational Supporting Tool among Nursing Students

2020 ◽  
Vol 4 (1) ◽  
pp. 67-77
Author(s):  
Rohimah Ismail ◽  
Chong Mei Chan ◽  
Wan Muhammad Azly W. Zulkafli ◽  
Hasnah Zani ◽  
Zainab Mohd Shafie
Keyword(s):  
Nursing Education ◽  
Nursing Students ◽  
Clinical Decision Making ◽  
Intervention Group ◽  
Great Influence ◽  
Control Group ◽  
P Value ◽  
Significant Difference ◽  
Supporting Tool ◽  
Nursing College

                The evolution of information technology has exerted great influence on nursing education via new pedagogy of knowledge delivery without time and place restriction. Mobile technology revolutionises nursing education and clinical practice via empowering skills of critical thinking and clinical decision-making through learning. The aim of this study is to evaluate the effectiveness of using mobile messenger (Whatsapp) as an educational supporting tool among nursing students. The study design used is a Cluster Randomized Control Trail. Two nursing colleges were selected. Sample size was 93 participants, 48 from the Kuala Terengganu Nursing College Kuala Terengganu as the intervention group while the control group were recruited among 45 participants from UniSZA Nursing College. There is a significant difference in the level of knowledge between pre and posttest among intervention group (mean difference was -8.70 with a standard deviation 8.42, p-value< 0.001) and 93.8 percent of the respondents perceived the usefulness of using WhatsApp mobile messenger to enhance learning. This demonstrates that learning through mobile messenger (WhatsApp) enhances learning and is well received as a new method of learning by almost all students.   Keywords: Mobile learning, WhatsApp messenger, Social Interaction

Maximum Temperature Through a Yttrium Stabilized Zirconia Ceramic After Er,Cr:YSGG Laser Irradiation

2020 ◽  
Vol 02 ◽  
Author(s):  
Laurel Stringer ◽  
Sarah Malley ◽  
Darrell M. Hutto ◽  
Jason A. Griggs ◽  
Susana M. Salazar Marocho
Keyword(s):  
High Speed ◽  
Potential Method ◽  
Maximum Temperature ◽  
Zirconia Ceramic ◽  
Tooth Pulp ◽  
Control Group ◽  
Stabilized Zirconia ◽  
Significant Difference ◽  
Power Setting ◽  
Group A

Background: The most common approach to remove yttria stabilized zirconia (YSZ) fixed-dental prostheses (FDPs) is by means of diamond burs attached to a high-speed handpiece. This process is time-consuming and destructive. The use of lasers over mechanical instrumentation for removal of FDPs can lead to efficient and predictable restoration retrievability. However, the heat produced might damage the tooth pulp (>42˚C). Objective: The purpose of this study was to determine the maximum temperature (T) reached during the use of different settings of the erbium, chromium:yttrium-scandium-gallium-garnet Er,Cr:YSGG laser through a YSZ ceramic. Methods: YSZ slices (1 mm thick) were assigned into 7 groups. For the control group, a diamond bur was used to cut a 1 mm groove into the YSZ slices. For the 6 experimental groups, the laser was operated at a constant combination of 33% water and 66% air during 30 s with two different power settings (W) at three frequencies (PPS), as follows (W/PPS): 2.5/20, 2.5/30, 2.5/45, 4.5/20, 4.5/30, 4.5/45. The T through the YSZ slice was recorded in degrees Celsius by using a digital thermometer with a K thermocouple. Results: The median T of the control group was 26.5˚C. The use of 4.5 W resulted in the median T (˚C) of 44.2 at 20 PPS, 53.3 at 30 PPS, and 58.9 at 45 PPS, while 2.5 W showed 34.6, 31.6, and 25.0 at 20, 30, and 45 PPS, respectively. KruskalWallis one-way ANOVA showed that within each power setting, the T was similar. The high power and lowest frequency (4.5/20) showed no significant difference from the 2.5 W settings and the control group. Conclusion: The lower power setting (2.5 W) is a potential method for the use of the Er,Cr:YSGG laser to debond YSZ structures. The higher power (4.5 W) with high frequencies (30 and 45 PPS) is unsuitable.

INFLUENCE OF FOOT INSOLE ON THE GAIT PERFORMANCE IN SUBJECTS WITH FLAT FOOT DISORDER

2019 ◽  
Vol 19 (06) ◽  
pp. 1950050
Author(s):  
M. T. KARIMI ◽  
R. B. TAHMASEBI ◽  
B. SATVATI ◽  
F. FATOYE
Keyword(s):  
Range Of Motion ◽  
Ankle Joint ◽  
Lower Limb ◽  
Walking Speed ◽  
Force Plate ◽  
Flat Foot ◽  
Gait Performance ◽  
Positive Effects ◽  
Significant Difference ◽  
Foot Disorder

Flat foot is the most common foot disorder that influences the alignment of the lower limb structure. It is controversial whether the use of foot insole influences kinetic and kinematic of the leg or not. Therefore, this study investigated the influence of foot insole on the gait performance in subjects with flat foot disorder. A group of flat foot subject was recruited into this study (the number of subjects was 15). The motion of the leg joints was determined using the Qualysis motion analysis system. Moreover, the force applied on the lower limb was recorded by a Kistler force plate. The range of motion of the lower limb joints, the moments applied on the lower limb joints and force transmitted through the leg were the parameters used in this study. The difference between these parameters during walking with and without insole was evaluated using the paired [Formula: see text]-test. Significant value was set at [Formula: see text]. There was no significant difference between the range of motion of ankle joint while walking with and without insole. However, the medial directed force applied on the leg decreased significantly [Formula: see text]. The use of foot insole did not influence the moments transmitted through the hip and knee joints. The walking speed of the subjects improved while walking with foot insole. Use of foot insole influenced the magnitude of the force applied on the leg and the adductor moment of ankle joint due to its influence on foot alignment. As the walking speed of the improved subjects follows the use of insole, it can be concluded that it may have a positive effects on the performance of flat foot subjects.

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