COMPARATIVE ANALYSIS OF MUSCLE ACTIVITIES DURING RESISTANCE EXERCISES USING VARIABLE AND ELASTIC LOADS

Over the last few decades, many resistance training devices and methods have been deve'loped for the purpose of increasing strength~ One of the most popular devices being used is variable resistance training (VRT) device (Baechle & Groves, 1992). This type of exercise machines has a major advantage that, by altering the shapes of cams, the resistance profiles at different joint positions can match the strength curve (maximum torque-angle curve) of a joint motion. Despite this advantage, the method has not been perfected and there are arguments against its effectiveness (Garhammer, 1989; Ward, 1993). The major disadvantages of this device are the relatively high cost and large space required. The elastic band exercise device such as elastic tubing is getting popular in recent years, especially in rehabilitation settings. To a certain extent, an elastic exercise device has characteristics similar to a variable resistance-training device. The major advantages of this device are its safety, inexpensiveness, and compact design. To evaluate the stresses placed on different upper arm muscles during a biceps curl using selected home exercise devices, it was the purpose of this study to examine the electromyographic (EMG) activities of the pectoralis major, biceps brachii, triceps brachii, and brachioradialis muscles during biceps curls using a VRT device and an elastic tubing

Local Whittle estimator for anisotropic random fields

AbstractA local Whittle estimator is developed to simultaneously estimate the long memory parameters for stationary anisotropic scalar random fields. It is shown that these estimators are consistent and asymptotically normal, under some weak technical conditions. A brief simulation study illustrates a practical application of the estimator

Temperature dependence of Mott transition in VO_2 and programmable critical temperature sensor

The temperature dependence of the Mott metal-insulator transition (MIT) is studied with a VO_2-based two-terminal device. When a constant voltage is applied to the device, an abrupt current jump is observed with temperature. With increasing applied voltages, the transition temperature of the MIT current jump decreases. We find a monoclinic and electronically correlated metal (MCM) phase between the abrupt current jump and the structural phase transition (SPT). After the transition from insulator to metal, a linear increase in current (or conductivity) is shown with temperature until the current becomes a constant maximum value above T_{SPT}=68^oC. The SPT is confirmed by micro-Raman spectroscopy measurements. Optical microscopy analysis reveals the absence of the local current path in micro scale in the VO_2 device. The current uniformly flows throughout the surface of the VO_2 film when the MIT occurs. This device can be used as a programmable critical temperature sensor.Comment: 4 pages, 3 figure

The Effect of the Rapid Antigen Test for Influenza on Clinical Practice in the Emergency Department: A Comparison of Periods before and After the 2009 H1N1 Influenza Pandemic

Introduction. The rapid antigen test (RAT) plays an important role in the Emergency Room (ER). In this study, we investigated the effect of the RAT for influenza on clinical practice in an emergency department. Methods. A retrospective chart review was conducted considering two periods, namely before and after the 2009 influenza pandemic. The rate of antibiotic administration, the use of blood sample tests, the use of simple chest X-rays, the rate of antibiotic administration according to the result of the RAT, and the duration of ER stay in the case of influenza-like illnesses were investigated for the two study periods considered. Results. The use of the RAT increased from 23.9% to 39.8% in influenza-like pediatric patients (p<0.05) and from 4.9% to 67.6% in adult patients (p<0.001). After the 2009 influenza pandemic, the number of cases of antibiotic administration, blood sample test and simple chest X-ray decreased by 19.0%, 46.2%, and 27.4%, respectively, in pediatric patients with the use of RAT. Among RAT-positive patients, after the 2009 influenza pandemic, none of the pediatric patients and only 3 of the adult patients (17.6%) were administered antibiotics. The duration of ER stay was longer in patients who underwent RAT than in those who did not. Conclusion. The increased use of RAT for influenza has led to a decrease in antibiotic administration and a reduction in additional diagnostic tests in influenza-like illnesses. However, the use of RAT has not contributed to a decrease in the duration of ER stay

THE EFFECTS OF WEARING ROLLER SHOES ON MUSCLE ACTIVITY IN THE LOWER EXTREMITY DURING WALKING

Roller shoes have become increasingly popular among children and its features of retractable wheels which allow the user to walk or roll without changing the footwear. Maintaining balance during forward walking with roller shoes is not an easy task. To prevent falling backward, the user needs to lock the knees and tighten the ankles and thighs while the upper body is slightly leaning forward. Constant walking with roller shoes forces the user to walk in a manner much different from normal gait. Prolonged exposure to un-natural stresses on human body forces our body to evolve by strengthening those incorrect and temporary functions (Clement et al., 1981). For children, the chronic stress may lead to serious injuries in the lower extremity later in life. If any potential of injury exists in a movement it is critical to examine the associated muscle activity that may lead to injury. To the best of our knowledge, the effects of wearing roller shoes on muscle activity in the lower extremity have rarely been studied, especially in the youth population. Thus, the purpose of this study was to compare muscle activity in the lower extremity during walking wearing jogging and roller shoes

Spatial Regression With Multiplicative Errors, and Its Application With Lidar Measurements

Multiplicative errors in addition to spatially referenced observations often arise in geodetic applications, particularly in surface estimation with light detection and ranging (LiDAR) measurements. However, spatial regression involving multiplicative errors remains relatively unexplored in such applications. In this regard, we present a penalized modified least squares estimator to handle the complexities of a multiplicative error structure while identifying significant variables in spatially dependent observations for surface estimation. The proposed estimator can be also applied to classical additive error spatial regression. By establishing asymptotic properties of the proposed estimator under increasing domain asymptotics with stochastic sampling design, we provide a rigorous foundation for its effectiveness. A comprehensive simulation study confirms the superior performance of our proposed estimator in accurately estimating and selecting parameters, outperforming existing approaches. To demonstrate its real-world applicability, we employ our proposed method, along with other alternative techniques, to estimate a rotational landslide surface using LiDAR measurements. The results highlight the efficacy and potential of our approach in tackling complex spatial regression problems involving multiplicative errors

DIRECTIONAL CONTROL IN TENNIS SERVES PERFORMED BY ELITE PLAYERS

This study quantified the pre-and post-impact 3-D kinematics of the ball and racquet during the serves that landed at different locations performed by five male and four female professional tennis players. Data were collected during competition using two high-speed cameras (200 Hz). Two first serves .-one landed near the center line and the other near the side line --were analyzed for each subject. A 2 x 2 ANOVA (0 < .05) was performed for each parameter. The results indicate that the males had significantly greater post-impact ball and racquet velocities than their female counterparts. Though not statistically significant, the ball tended to travel to the left less during the toss and have lower post-impact velocity for serves that landed near the side line. Altering the toss might be one of the strategies used by players to control ball direction in the serve