The effect of different systems of carrying backpacks on muscle activity

Introduction: The purpose of this study is to compare the muscles activity in different systems of carrying the load in students and mountain climbers. EMG activity for TA and LD muscles were recorded with surface electrode while walking with different conditions. 26 young students attended three test sections in three days apart. After warm up subjects walked 10 min on the treadmill without backpack as a normal position in the first day. On the second day subjects walked 10 min with normal backpack, and on third day they walked 10 min with counterbalance load backpack. EMG activity of the TA and LD measured during three conditions of walking. One way analysis of variance (ANOVA) was applied on EMG patterns at muscles. The results indicated that there is a significant difference in TA and LD activities after walking with normal backpack and walking without backpack. There is an also significant difference in TA and LD activities between walking with normal backpack and counterbalance backpack. Results also indicated that there is no significant difference between walking without backpack and walking with counterbalance backpack with p<.856. Findings of this study clearly show the advantage of a counterbalance system for carrying the loads. In addition to these, the reduction of muscle activity is a considerable kinematic and ergonomic benefit of carrying load in such backpacks

Gait analysis of national athletes after anterior cruciate ligament reconstruction following three stages of rehabilitation program: symmetrical perspective

This study aimed to objectively evaluate changes in gait kinematics, kinetics and symmetry among anterior cruciate ligament (ACL) reconstructed athletes during rehabilitation. Twenty-two national athletes with ACL reconstruction and 15 healthy athletes were recruited for the study. Gait data were collected between the weeks 4–5, 8–9, and 12–13 post-operation using three-dimensional motion analysis system. Five separate components, including knee range of motion (ROM), vertical ground reaction force (VGRF), their symmetries and knee extension moment were evaluated. One way and repeated measure multivariate analysis of variance (MANOVA) were used to analyze the knee ROMs. The VGRF and extension moment were tested using repeated measure ANOVA and independent sample t-test. Findings indicated significant alterations in all measured components between patients’ Test 1 and control group. Repeated measure analysis revealed significant effect for time in components of knee angular and VGRF (P < 0.001), their symmetry index (P = 0.03) and knee extension moment (P = 0.045). Univariate outcomes demonstrated significant improvement in the injured limb's stance and swing (P < 0.001), and single-stance (P = 0.005) ROMs over time. Symmetry indexes of stance and swing ROM, and VGRF reduced significantly by 26.3% (P = 0.001), 17.9% (P < 0.001), and 31.9% (P = 0.03) respectively. After three months, symmetry indexes of single-stance ROM and VGRF along with operated knee extension moment were the only variables which showed significant differences with control group. The rehabilitation program allowed national athletes to restore the operated limb's gait parameters except knee extension moment by 12–13 weeks post-reconstruction; however, more time is required to normalize single-stance ROM and VGRF asymmetries

Gunung Tahan Trail: a historical review

There are still a lot of information on the history of Gunung Tahan Trail which remain unknown to the Malaysian public; some were buried with the demise of the elderly living around this mountain. This paper attempts to reveal the history of this famous trail which is located in Taman Negara in relation to the origin of its name, local belief and folklore of the mountain, colonial proposal for the establishment of grand hill station and early attempts to explore the mountain. Most of the data and information for this review were gathered from field notes and expedition reports published in various journals between 1880 and 1940. These information would be useful to Taman Negara Park Management in enriching recreational and nature tourism experiences among users of Gunung Tahan Trail

Different performance characteristics among students in Malaysia

The main aim of this study is to examine and define performance characteristics for the male students and female students in 3 types of school in Malaysia. A sample of 1083 students (male=625, Female 458) age between 13 years to 16 years participated in this study. The students are from 3 different types of school, namely National Sport School (n=300), State Sport School (n=333) and Normal School (n=450). There were 190 male and 110 female from National Sport School, 210 male and 123 female from State Sport School. Meanwhile, there were 225 male and 225 female from the Normal School. The students from National Sport School and State Sport School consists of young athletes. Meanwhile, the students from Normal School just ordinary students with various backgrounds. Height and weight measurement is to indicate students’ anthropometry measurement. Furthermore, the students have been tested with 6 physical fitness tests to indicate their physical performances (standing broad jump, sit and reach, 30-meter sprint, 7 level sit-up, 10-meter shuttle run, bleep test). The results of this study show that anthropometry measurement and physical performance test can be used to discriminate between students in the different type of school (NSS, SSS, NS). Besides that, this study showed that there were different performances in the physical test among students, which can help to discriminate students into the different school

Perubahan prestasi fizikal dan tumbesaran dalam kalangan murid berumur di antara 9 hingga 12 tahun

Tujuan kajian ini adalah untuk mengenal pasti perubahan prestasi fizikal dan tumbesaran pelajar lelaki dan pelajar perempuan berumur antara 9 tahun hingga 12 tahun. Kajian ini adalah berbentuk rentas silang (cross-sectional) melibatkan sampel sebanyak 400 orang (murid lelaki=200, murid perempuan=200) yang dibahagikan kepada empat kumpulan umur (9 tahun, 10 tahun, 11 tahun, 12 tahun). Petunjuk tumbesaran didalam kajian ini adalah ukuran tinggi berdiri urid. Enam ujian prestasi fizikal dijalankan untuk menguji tahap prestasi fizikal murid iaitu ujian tekan tubi (TT), ujian lompat jauh berdiri (LJB), ujian lari pecut 30 meter (LP), ujian duduk jangkau (DJ), ujian lari ulang alik (LUA), dan ujian bleep (UB). Dapatan kajian ini menunjukkan tumbesaran puncak pelajar lelaki berlaku ketika berumur antara 9 tahun hingga 10 tahun iaitu meningkat sebanyak 9.1 cm. Manakala, tumbesaran pesat pelajar perempuan berlaku ketika berumur 10 tahun hingga 11 tahun dengan peningkatan sebanyak 7.6 cm. Perubahan prestasi fizikal pelajar lelaki meningkat seiring dengan proses tumbesaran dan perubahan prestasi fizikal pelajar perempuan menunjukkan kemerosotan prestasi seiring dengan proses tumbesaran. Selain itu, perubahan terhadap prestasi fizikal berlaku pada umur yang berbeza bagi pelajar lelaki dan pelajar perempuan. Secara keseluruhannya, tumbesaran (tinggi) pelajar lelaki dan pelajar perempuan mempunyai hubungan yang signifikan dengan prestasi fizikal bagi kumpulan umur 9 tahun hingga 12 tahun

Effect of exercise modes with similar intensities on lipid-peroxidation and muscle-damage markers on sedentary males.

Depending on the intensity of a physical activity, exercise may impose negative effects on health. This study was conducted to evaluate the effect of the exercise modes with variety intensity levels on the serum concentration of lipid peroxidation and muscle damage markers in sedentary males. Eighty one sedentary healthy males were randomly divided intosix groups; three groups attending single-session aerobic exercise with low (n=14), moderate (n=14), and high (n=13) intensities, and three groups were subjected to single-session resistance exercise with low (n=13), moderate (n=13), and high (n=14) intensities. Data analysis showed that the mode of exercise has similar effect on the serum levels of malondial dehyde (MDA)and creatine kinase (CK). It was also found that the observed difference in the effect of low intensity levels of the modes of exercise was statistically significant, only for MDA post-test, not for CK. No significant differences w ere observed between the effect of both moderate and high intensity levels of aerobic and resistance exercise on both MDA and CK post-test. The results of this study suggest the low intensity level of aerobic and resistance exercise to be applied for more preparation, physical fitness and adaptation to prevent lipid peroxidation and muscle damage in sedentary males

Moderation role of attitude on the relationship between participation in competitive sports and academic performance of student-athletes in Saudi Arabia

Background: This study aims to investigate how the attitude of undergraduate student-athletes moderates the relationship between competitive sports participation (CSP) and academic performance (AP). In this study, a type of attitudes was taken into consideration namely academic performance attitude (APT). Methods: A total of 102 undergraduate student athletes from 3 academic institutions in the Eastern Region of Kingdom of Saudi Arabia (KSA) were selected as subjects. Instruments used were Survey of Study Habits & Attitudes (SSHA) by Brown and Holtzman, to obtain the data on APT. The instrument was back-translated to the Arabic language in order to improve its comprehensiveness. Data on sports participation and academic performance were obtained by directly enquire the participants about their grade point average (GPA) and the frequency of their CSP in a self-developed questionnaire. Results: The results showed that APT significantly alters the effect of CSP on AP, because the β value of the effect of CSP on AP was greater than the β value of the effect of CSP and APT on AP. Because β value shows the strength of the influence, it can be concluded that the actual strength of the CSP is not as strong as when it is combined with APT. In other words, APT moderates the influence of CSP on AP. Discussion: The moderation effect occurs due to the regulation of Saudi Universities Sports Federation (SUSF) that only student-athletes with required academic scores can participate in competitive sports. Without such a regulation, APT might not be correlated to the AP because some students might pay more focus on CSP and less on AP. It can be concluded that the regulation helped student-athletes in KSA to improve their AP without sacrificing their CSP and vice versa

Ground reaction force during walking with and without counterbalance load system

The purpose of this study was to determine the ground reaction force (GRF) during walking with and without counterbalance load system. Peck GRF was recorded with force plate while walking with different conditions on the treadmill. Twenty-six students (age was 22.41±1.75 years) attended three test sections in three days apart. Participants after 10 min warm up walked 10 min on the treadmill without any backpack in the first day. On the second day they walked 10 min with normal backpack, and on third day they walked 10 min with counterbalance load backpack. Force peck measured during three conditions of walking. A one way analysis of variance (ANOVA) was conducted for the force peaks variable, to confirm the significant difference between walking with different conditions. If statistical significance was found a between conditions a Tukey post-hoc test was used to examine where the differences exist within the conditions, where applicable. The results of current study showed significant difference in GRF after walking in three condition with p<.05. Within group analysis showed significant difference in GRF after walking with normal backpack and without backpack. In fact the normal backpack load significantly increased GRF when walking on the treadmill. The results also showed that there is no significant difference among GRF between unloaded walking and counterbalance backpack. Findings of current study clearly show the advantage of a counterbalance system for carrying the loads. In addition to these, the reduction of forces is a considerable kinematic and ergonomic benefit of carrying load in such backpacks

Anatomical Shoulder Movement Strength Imbalance Among Water Polo Overhead Athletes

Background: The game of water polo has become more familiar to all the athletes and coaches as the time has passed. It has been played as a sport for more than a century Although anatomical shoulder movement strength balance is a crucial factor in overhead throwers’ performance, it has not been studied extensively in the previous research. Objective: This study examined shoulder movement imbalance in bilateral and dominant anterior-posterior shoulder among 42 elite water polo players in Malaysia. Method: The t-test analyses of data obtained through several tests proved that water polo players had statistically significant difference between their right hand anatomical shoulder movement strength and their left hand anatomical shoulder movement strength in all eight shoulder movements, i.e. Flexion, Extension, Abduction, Adduction, Horizontal Adduction, Horizontal Abduction, Rotation and External Rotation. Results: The results of this study showed that there are significant differences of anatomical shoulder movement strength in both bilateral and Anterior-posterior shoulder movement among water polo players. The statistics results for bilateral shoulder movement of Flexion (t= 136.09 and p<.001), Extension (t= 110.92 and p<.001), Abduction (t= 121.89 and p<.001), Adduction (t= 101.47 and p<.001), Horizontal Adduction (t= 92.3 and p<.001), Horizontal Abduction (t= 95.6 and p<.001), Internal rotations (t= 109.6 and p<.001) and External rotations (t= 102.18 and p<.001) showed the p-value to be less than 0.05 for all variables of the test. The result of paired samples t-test showed there is a statistically significant difference between the mean of bilateral anatomical shoulder movement strength among water polo players. Conclusion: These findings suggest that coaches and players should take into account the shoulder movement strength imbalance in their trainings and design specific training programs to improve overhead throwers’ shoulder movement strength balance and hence their throwing performance in sports such as water polo

The ARX and ARMAX models for thermoelectric cooling on glass windows: a comparative study

Thermoelectric cooling (TEC), in particular, can be combined with a heat sink for local cooling, but they can also be integrated into electronic chips for point-to-point cooling. The study aims to develop a dynamic model of a cooling system integrated with TEC for glass window. The main target of this study is to develop a dynamic model of a cooling system integrated with TEC. The black box modelling approach in producing a mathematical model was selected based on the ARMAX and ARX model that corresponds to the actual dynamic state of the cooling system. The best model was finalized based on the best match on curve patterns when comparing the real and estimated models using the system identification tools in MATLAB, and also having the least error. The accuracy of the models was compared and analysed. The results showed that the 4th order of the ARMAX model produced a higher best fitting and standard deviation values of 80.23% and 0.027592 compared to the 4th order of the ARX model of 78.14% and 0.030769 respectively. This system accuracy is almost within the acceptable range for most error calculations in the validation method. Yet, this cooling system integrated with TEC is found more suitable for the 4th order of the ARMAX model when compared to the ARX model due to the noise parameter in the ARMAX model. Nevertheless, the noise order in this system is not dominant, therefore, whenever the noise order of the system in the ARMAX model is high than the second structure (nb), the number of errors is also high. In addition, the ARMAX model is found incapable of achieving the highest fitting due to the losses from the dynamic environment and losses from the TEC itself. Still, the use of this black box model used in this study is a significant variation where system parameters can be identified even offline