Side Step Research Articles

Bulk and surface topological indices for a skyrmion string: current-driven dynamics of skyrmion string in stepped samples

The magnetic skyrmion is a topological magnetic vortex, and its topological nature is characterized by an index called skyrmion number which is a mapping of the magnetic moments defined on a two-dimensional space to a unit sphere. In three-dimensions, a skyrmion, i.e., a vortex penetrating though the magnet naturally forms a string, which terminates at the surfaces of the magnet or in the bulk. For such a string, the topological indices, which control its topological stability are less trivial. Here, we study theoretically, in terms of numerical simulation, the dynamics of current-driven motion of a skyrmion string in a film sample with the step edges on the surface. In particular, skyrmion–antiskyrmion pair is generated by driving a skyrmion string through the side step with an enough height. We find that the topological indices relevant to the stability are the followings; (1) skyrmion number along the developed surface, and (2) the monopole charge in the bulk defined as the integral over the surface enclosing a singular magnetic configuration. As long as the magnetic configuration is slowly varying, the former is conserved while its changes is associated with nonzero monopole charge. The skyrmion number and the monoplole charge offer a coherent understanding of the stability of the topological magnetic texture and the nontrivial dynamics of skyrmion strings.

Validation of Accelerometry Data to Identify Movement Patterns During Agility Testing

Purpose: The purpose of this study was to develop an algorithm for the detection and timing of foot contact/off timing for each lateral repetition and assess the validity/reliability of the calculated timings.Methods: Participants performed a modified Edgren Side Step Test in which they moved laterally along a 4-m path as quickly as possible while wearing an accelerometer on each ankle. Time of completion of each attempt was recorded using a stopwatch and digital video was obtained. Accelerometer-based (ACC) events were determined for the start of the test (START), foot contact at the end-line (FC) and the lifting of the foot when transitioning to the other direction (FO). Based on these ACC events the Overall, Split (ST) and Lag (LT) times were determined and compared to either the stopwatch or video-based timings (p < 0.05). The ACC event criterion was then applied by independent reviewers to assess inter/intra-rater reliability of identifying the events.Results: There was no significant difference in ACC (12.37 ± 2.19 s) based Overall Time compared to the Stopwatch (12.42 ± 2.25 s, p = 0.34). Bland-Altman plots for ST and LT revealed very good agreement between the ACC time to the Video (ST: Bias = 0.11 s, LOA −0.57 to 0.79; LT: Bias = −0.11 s, LOA −0.43 to 0.22). Intra and inter-rater reliability was moderate to excellent for all reviewer identified events.Conclusions: This study demonstrates methodology to identify ACC based timings during an agility test. The inclusion of an accelerometer supplements standard timing options with the added benefit of assessing sided split and lag times.

Proprioceptive training in dance sport: effects of agility skills

The aim of this research is to determine the effects of proprioceptive training on the improvement of agility skills in dance sport fitness conditioning. Proprioceptive training is realized throughout tasks that include the establishing and maintaining various positions on balance boards of different dimensions, working surfaces and platforms. 38 male and female competitive dancers divided into an experimental and control groups. The experimental group took part in a proprioceptive training program over a period of 12 weeks (3 x 30 minutes per week). The control group (at the same time as the experimental) had regular sport dance training. At the beginning and at the end of the experiment, agility skills were measured by means of three different agility tests: Side steps, Figure '8' with bending and Agility in the air. Statistically significant differences among the groups in the final measurement (p= .00) generally show a positive effect of the proprioceptive training program on the improvement of agility skills with the experimental group, especially in tests Figure '8' with bending and Side steps. Such findings could encourage the use of proprioceptive training model in daily dance classes due to its potential to improve dancers' agility skills. Therefore, the use of a proprioceptive training model, as an innovative approach in individual and group dance fitness conditioning is recommended.

Intelligent models for movement detection and physical evolution of patients with hip surgery

Abstract This paper develops computational models to monitor patients with hip replacement surgery. The Kinect camera (Xbox One) is used to capture the movements of patients who are performing rehabilitation exercises with both lower limbs, specifically, ‘side step’ and ‘knee lift’ with each leg. The information is measured at 25 body points with their respective coordinates. Features selection algorithms are applied to the 75 attributes of the initial and final position vector of each rehab exercise. Different classification techniques have been tested and Bayesian networks, supervised classifier system and genetic algorithm with neural network have been selected and jointly applied to identify the correct and incorrect movements during the execution of the rehabilitation exercises. Besides, prediction models of the evolution of a patient are developed based on the average values of some motion related variables (opening leg angle, head movement, hip movement and execution speed). These models can help to fasten the recovery of these patients.

Performance analysis of desiccant wheels assisted fresh air humidifiers in winter using natural gas boilers: Applied in cold and dry climate regions

A fresh air handling unit is proposed for space humidification in winter for buildings located in cold and dry climate regions. The air handling unit has three-stage desiccant wheels to transfer moisture from dehumidification air (A deh ) to humidification air (A hum ), both of which are from outdoor, and heat from boilers is used to drive this process. Humidification performances of this device were discussed when ambient humidity ratio was from 1 to 4.5 g kg −1 and corresponding operating strategies under different ambient conditions were proposed to keep the supply humidity ratio in the range of 5.1–5.5 g kg −1 . Then, effective heating systems, including air side heat recovery and step utilization of heat from low-grade waste heat, were investigated. Humidification efficiency ( η sys ) of systems without heat recovery ranges from 0.24 to 0.9. With heat recovery at the air side, which is called improved system I, η sys was enhanced to 0.4–1.2. Water circulation layout was redesigned to realize step utilization of heat. Return water temperature from humidification devices could be reduced, and η sys can be obviously enhanced when low-grade waste heat sources are available. When air source heat pumps are used to preheat the return water, from Case A to Case H, primary energy efficiency can be improved by 5.8–26.1% as compared with the improved system I.

THE INFLUENCE OF INTEGRATION OF PHYSICAL AND MUSIC EDUCATION ON CLASS TEACHING STUDENTS MOTOR SKILLS DEVELOPMENT

The aim of this research was the integration of Physical and Musical activities to the development of motor skills of class teaching students. The sample of 64 survey participants consisted of primary school students, aged 9 and 10 (± 6 months) from Niš and divided into two groups - experimental and control group, 32 participants in each group. The participants from the experimental group participated in the additional Physical Education lessons which included coordination and speed exercises, that is, the integrated lessons, while the survey participants from the control group were included only in regular Physical Education lessons, and also in Music Education lessons. The following motor skills were examined: Speed, Agility, Flexing, Explosive strength, Repetitive strength and Segmental speed. The obtained results show that there is a statistically significant difference in 20 meter run with the elongated start (M20VS .000), 30 meter run with the elongated start (M30VS .000), figure-of-eight agility run test (MKOT .000), side steps (MKUS .000), standing forward bend (MDPK .000), split (MŠPA .000), standing long jump (MSDM .000), standing triple jump (MTRS .000), foot tapping (MTAN .005) and hand tapping (MTAP .001). Given the results obtained, the design of a special program that would include the integration of the content of these subject areas would contribute to the development of elementary physical and musical skills.

Optimal Design of Presplit Blasting Network of Deep Concave Open-Pit Mine Slope with Heterogeneous Complex Rock Mass

To ensure that the mining steps of deep concave open-pit coal mines with heterogeneous complex rock masses in arid areas are safely bounded by the design requirements and form a fixed side wall, to avoid the occurrence of instability and disaster caused by blasting vibration, based on non-homogeneous rock mass structure, lithology characteristics, fracture surface composition, morphology and joints, analysis of fissure development trend, and case studies of wedge-shaped landslide accident caused by blasting vibration, we proposed: (1) The pre-split instantaneous denotation charge is the dosage used for the segment unit charge of the primary blast hole and buffer hole, and it’s used for calculating . Based on this, the time intervals of segmented detonating cord and fuse are calculated and the actual detonating unit charge is decided. (2) Leave lateral free surface on the fixed side boundary and drill inclined blast holes along the slope of the steps, connect detonating cords to the blasting network, multi-point instantaneous detonate uncoupled segmented charge holes, use the pre-crack and fracture surface to reduce the damage caused by the explosion shock wave of the primary and buffer blasting holes. (3) The main blast hole and buffer hole are connected by non-conductive detonating cord and “four-way” blasting network, couple continuous concentrated charge using non-conductive detonating cord and fuse plus or detonator plus segmented ammonium dynamite initiator and expanded ammonium oil charge for millisecond interval detonation. Control the number of blasting holes and unit detonating charge over equal segments of fuse and detonating cord, reduce the impact of close-range blasting vibration of vertical deep holes on fixed side wall and step slope. Results of the blasting experiment show that using the technology of detonating cord in combination with non-conductive detonator’s pre-split hole millisecond differential blasting network plus reserved free face and segmented unit charge detonation, provide 1-2 blasting lateral free face or positive free face, making the blasting effect dispersed around the blasting hole. It has better solved the major safety problem of instability and disaster caused by the blasting effect on the fixed border-to-boundary steps of deep concave open-pit mine in arid region.

Relative and Absolute Reliability of a Motor Assessment System Using KINECT® Camera.

(1) Background: Virtual reality is currently useful in different clinical specialties as a diagnostic and therapeutic tool. In this study, we analyzed the relative and absolute reliability of the motor evaluation with the Kinect camera, a markerless motion system. (2) Methods: Observational study in healthy people, whose inclusion criteria were: healthy people, age 18 to 40 years old without pathologies or injuries in osteoarticular structures or ligamentous muscle and pharmacological treatment with influence on motor skills. Fifty-two subjects were evaluated. (3) Results: The results of the relative reliability were favorable in variables such as the amplitude of passage of the right leg (ICC (Intraclass Correlation Coefficient) = 0.95 ± 0.03), the step width of the left leg (ICC = 0.92 ± 0.04) or balance of the left leg (ICC = 0.90 ± 0.05). Moderate values were found for other variables. The absolute reliability, measured by the coefficient of variation, was favorable in most of the variables. (4) Conclusions: The results reflect a favorable intraclass correlation in the evaluation of the variation and asymmetry of movements of the upper limbs, the balance of both legs, the side step width and the evaluation of the sitting and standing positions. The reliability of the evaluation of the variation of movements and the asymmetry of the lower limbs must be further improved.

The Pedi-CHAMP Agility Test: Completion Rates For Typically Developing Children Aged 5 To 17yrs

The Comprehensive High-Level Activity Mobility Predictor (CHAMP) was developed to assess the rehabilitation and performance in active military service-members who sustained traumatic injury. A pediatric version of this 4-part agility test (the Pedi-CHAMP) has been adapted for use in children aged 5 to 17 years. The Pedi-CHAMP consists of a) 30sec single limb stance (SLS) on each leg, b) a modified Edgren Side-Step Test (Edgren) consisting of 3 continuous repetitions of side-step movements in each direction over a 4m course c) an L-test (10m forward, 10m side-step in each direction, 10m backwards) and d) the Illinois Agility Test (IAT) triple shuttle run with directional weaving on the second pass. PURPOSE: To assess the completion rate of each portion of the Pedi-CHAMP in typically developing children aged 5 to 17 years. METHODS: With IRB-approval, 1,093 children (574 females, average age 11.0±3.9yrs (range 5.0-17.9yrs) were tested and included for analysis. Each participant was given two attempts to complete each portion of the test. If one attempt was unsuccessful or disqualified based on performance, a third attempt was offered. Participants were grouped by age (rounded down to the nearest year) and sex (male/female). A complete test was noted if the participant was able to follow directions and did not demonstrate any performance deemed to disqualify the trial (missed end line/cone, failed to maintain proper body position during side step, etc.) RESULTS: All participants were able to follow the directions and perform the SLS test. It should be noted, however, that 29% were not able to maintain balance for 30 secs on one or both legs. The SLS rate of completion was higher in girls than boys for children aged 5 to 11 years. The overall completion rates for the modified Edgren and L-test tasks were 93% and 92%, respectively. Similar trends between sexes were seen for both tests, with completion rates improving from 74% (Edgren) and 69% (L-Test) in children aged 5yrs to <90% by 8yrs of age. The Illinois Agility Test (IAT) had an overall completion rate of 99%, with all age-sex groups achieving at least 92% completion. CONCLUSION: The Pedi-CHAMP is a 4-part agility test that can be successfully administered in typically developing children aged 5 to 17yrs.

Effect Of Exercise Intervention On Physical Fitness Factors In Elementary School Children

Sports have been very popular after-school activities for children. It is quite likely that sports have a positive effect on child growth in many ways. The Ministry of Education, Culture, Sports, and Technology of Japan has reported that the total scores of physical fitness tests differ greatly between those who exercise regularly and those who do not. However, it is not clear how exercise habits affect physical fitness factors during childhood. Such detailed knowledge would be useful in promoting long-term athlete development and improving physical fitness throughout life. PURPOSE: To explore the effect of exercise intervention on physical fitness factors in elementary school children. METHODS: The subjects of this study were 1,079 1st- to 6th-grade male elementary school students. A questionnaire survey was conducted to investigate the exercise and lifestyle habits and the results of physical fitness tests conducted at Japanese elementary schools. The existence or not of exercise habits after-school activities and the results of physical fitness tests were used for the analysis. The physical fitness test includes measurements of grip strength, sit-ups, sitting front stretches, side steps, twenty-meter shuttle run, fifty-meter run, standing long jump, softball throw, height, and weight. RESULTS: There were no significant differences between grades in the existence or not of exercise habits about height and weight. After the 3rd grade, children with exercise habits showed higher performance on sit-ups, side steps, the twenty-meter shuttle run, the fifty-meter run, and softball throw than children with no exercise habits. There was little difference in grip strength, sitting front stretches, and long jump between children with exercise habits and those without. CONCLUSION: Endurance, speed, and agility develop greatly in elementary school children who exercise regularly. However, exercise habits have little effect on single strength and power. In addition, differences between children with and without exercise habits are observed after the 3rd grade.

Detection and classification of single-trial movement-related cortical potentials associated with functional lower limb movements

Objective. Brain-computer interfaces that activate exoskeletons based on decoded movement-related activity have been shown to be useful for stroke rehabilitation. With the advances in the development of exoskeletons it is possible to replicate a number of different functional movements that are relevant to rehabilitate after stroke. In this study, the aim is to detect and classify six different movement tasks of the lower extremities that are used in the activities of daily living. Approach. Thirteen healthy subjects performed six movement tasks (1) Stand-to-sit, (2) Sit-to-stand, (3) Walking, (4) Step up, (5) Side step, and (6) Back step. Each movement task was performed 50 times while continuous EEG was recorded. The continuous EEG was divided into epochs containing the movement intention associated with the movements, and idle activity was obtained from recordings during rest. Temporal, spectral and template matching features were extracted from the EEG channels covering the motor cortex and classified using Random Forest in two ways: (1) movement intention vs. idle activity (estimate of movement intention detection), and (2) classification of movement types. Main results. The classification accuracies associated with movement intention detection were in the range of 80%–90%, while 54 ± 3% of all movement types were classified correctly. The stand-to-sit and sit-to-stand tasks were easiest to classify, while step up often was classified as walking. Significance. The results indicate that it is possible to detect and classify functional movements of the lower extremities from single-trial EEG. This may be implemented in a brain-computer interface that can control an exoskeleton and be used for neurorehabilitation.

Effects of Dynamic Stretching Combined With Static Stretching, Foam Rolling, or Vibration Rolling as a Warm-Up Exercise on Athletic Performance in Elite Table Tennis Players.

Warm-up exercise is an essential preexercise routine for athletes to optimize performance. However, the benefits of combined warm-up protocols remain unclear. This comparative study investigated the acute effects of dynamic stretching (DS) followed by static stretching (SS), self-myofascial release using a foam rolling (FR) device, or vibration foam rolling (VFR) as a warm-up exercise to improve flexibility, power, agility, and specific skills in elite table tennis players. A crossover study. University. Twenty-three elite table tennis players. Players completed 3 different interventions in a random order (DS + SS, DS + FR, and DS + VFR). The target muscle groups included the bilateral posterior calf, posterior thigh, anterior thigh, back, and shoulder. Sit-and-reach test for flexibility, board jump test for lower-extremity power, medicine ball throw test for upper-extremity power, Edgren Side Step Test for agility, and ball speed of table tennis was assessed before and after intervention. After intervention, significant increases in flexibility (15.2%, 20.4%, and 23.8%); lower-limb power (4.5%, 6.6%, and 6.3%); upper-limb power (9.6%, 8.5%, and 9.1%); and ball speed (7.4%, 7.6%, and 7.7%) were observed for DS + SS, DS + FR, and DS + VFR, respectively (all P < .001). In addition, only DS coupled with FR (5.1%) and DS in conjunction with VFR (2.7%) significantly improved agility (P < .001). However, no significant improvements in agility were observed after DS + SS. In addition, no one protocol was superior to the other in all outcomes. The authors suggest that a combination of DS with FR or VFR as warm-up exercises significantly improved flexibility, power, ball speed, in addition to agility in elite table tennis players. Coach and athletic professionals may take this information into account for choosing more effective warm-up protocols to enhance performance.

THE RELIABILITY OF A QUALITATIVE SCORING SYSTEM OF TRUNK AND LIMB ALIGNMENT DURING A 45-DEGREE SIDE STEP CUT

Background:Three dimensional (3D) motion analysis is considered the “gold standard” for evaluating human movements. However, its clinical utility is limited due to cost, operating expertise and lengthy post-processing time. Numerous qualitative scoring systems, using videos, have been introduced to assess trunk and lower extremity (LE) alignment in dynamic maneuvers. However, it is unknown if a qualitative scoring system is a reliable method to evaluate cutting movement.Hypothesis/Purpose:To assess the inter-rater and intra-rater reliability of a qualitative scoring system to evaluate trunk and LE alignment during a 45-degree side step cut. The sub-aim was to investigate the effect of interactive peer discussion on inter-rater reliability.Methods:A repeated measures study design was used. Six raters (2 MDs, 2 PTs, and 2 ATs) independently viewed 10 videos, consisting of a 45-degree side step cut performed by adolescent male and female athletes. A clinically established checklist (Figure 1) was given to examine quality of movements. After the 1st round, an interactive peer discussion was held to discuss videos, movement quality, and the checklist. Subsequently, after a 1-week wash out period, a 2nd round of evaluation (examining the same 10 videos) was performed. Following the 2nd round, and a 2-week wash out period, a 3rd round was performed to assess intra-rater reliability. In each round, video sequences were altered in random order to avoid memory bias. Intraclass correlation coefficient (ICC) and their 95% confident intervals (95% CIs) were calculated. Values less than 0.50, between 0.50 and 0.75, between 0.75 and 0.90, and greater than 0.90 were defined as poor, moderate, good and excellent reliability, respectively.Results:Inter-rater reliability for the 1st round was moderate (ICC: 0.565, 95%CIs: 0.074-0.866). Inter-rater reliability for the 2nd round was better, however, was still moderate (ICC: 0.632, 95%CIs: 0.100-0.895). Intra-rater reliability between the 2nd and 3rd round ranged from moderate to excellent (ICC: 0.589-0.910).Conclusion:The results of this study showed moderate inter-rater reliability and moderate to excellent intra-rater reliability of the qualitative checklist. Following the interactive peer discussion, slight improvements in inter-rater reliability were observed. The findings indicate that this checklist may allow clinicians to standardize their assessment of trunk and LE alignment during a cutting task, however, more objective methods to evaluate multiplane movements, such as genu valgum, may be warranted.Figure 1.45-Degree Side Step Cut Checklist

Comparative analytical study of Some Biomechanical Variables of the Wall barrier of Stability and Motion in Volleyball

The goal of the research is to identify the following: 1-Evaluate some of the biomechanical variables of the wall barrier skill of stability and motion in volleyball. 2-Differences in some biomechanical variables between the barrier wall skill of stability and motion in volleyball. The researcher hypothesized that there are differences of statistical significance in the values ​​of some biomechanical variables between the barrier wall skill of stability and motion in volleyball. The researcher used the descriptive approach in the method of analysis and comparison to the relevance of the nature of the research. The researcher conducted the final field experiment on a sample of (5) advanced players representing the team of the University of Mosul volleyball، and were chosen in a deliberate way. The researcher used the technical scientific observation، the questionnaire، the measurement، the analysis and the test، as a means of collecting data to obtain the research variables under study. The researcher also used the following programs in the analysis: 1 - MAX TRAQ 2 - ACD See Statistical methods: arithmetic mean، standard deviation، T test of associated samples. The researcher reached the following: 1-There are significant differences in the variable velocity of the corner of the body from the maximum flexion until the moment left the ground between the barrier wall of stability and motion and in favor of the barrier wall of the resistance of the motion. 2-There are significant differences in the variable motor kinetic motion of Mtcj maximum of flexion until reaching the highest rise between the wall of the resistance of stability and motion and in favor of the wall of the resistance of the motion. 3-There are significant differences in the variables (total time، displacement and vertical speed of Mtkj، angular velocity of the knee joint، angular velocity of the trunk، vertical momentum، corner velocity of the hip joint in favor of the wall of the motion. The researcher recommended. 1- Emphasis on the main section of the motion, ie, the state of readiness and readiness and start to perform the wall of the correct form. 2 - Emphasis on the side step to prepare for the advancement because of the role of large in the player to get a vertical shift and thus get a vertical speed to enable it to reach the highest altitude.

방향전환 동작 시 골반 사전운동이 하지분절 운동역학적 변인에 미치는 영향

Purpose: The purpose of this study is to analyze the effect of pre-orientation of the pelvis on kinematic and kinetic variables of the lower extremity injury during 90˚SSC (side step cutting). This study is also to investigate the relationship between pelvic pre-orientation and lower extremity injury during the SSC.BR Method: Nine healthy male college students participated in this study. Three dimensional motion analyses were used to analyze the kinematic and kinematic variables of A-SSC (typical SSC) and B-SSC (SSC which suppressed pre-orientation of the pelvis) during WAP (weight acceptance phase).BR Results: The approach velocity reached to side cutting point was not significantly different between the two SSCs. Pelvic pre-orientation significantly decreased in the B-SC. The maximum ground reaction force and the location of the center of gravity significantly increased laterally in the A-SSC. Landing distance and last step length both increased with the B-SSC. The maximum angles of knee and hip were not significantly different except the valgus angle of knee joint. The knee valgus and internal rotation moment increased significantly in the A-SSC.BR Conclusion: The length of the last step increased laterally in the B-SSC, but did not increase with the valgus and internal rotation moment of the knee joint. Therefore, even if the pelvic pre-orientation is suppressed during the SSC, it does not seem to have any negative effect on the non-contact knee injury.

Small stepping motion of processive dynein revealed by load-free high-speed single-particle tracking

Cytoplasmic dynein is a dimeric motor protein which processively moves along microtubule. Its motor domain (head) hydrolyzes ATP and induces conformational changes of linker, stalk, and microtubule binding domain (MTBD) to trigger stepping motion. Here we applied scattering imaging of gold nanoparticle (AuNP) to visualize load-free stepping motion of processive dynein. We observed artificially-dimerized chimeric dynein, which has the head, linker, and stalk from Dictyostelium discoideum cytoplasmic dynein and the MTBD from human axonemal dynein, whose structure has been well-studied by cryo-electron microscopy. One head of a dimer was labeled with 30 nm AuNP, and stepping motions were observed with 100 μs time resolution and sub-nanometer localization precision at physiologically-relevant 1 mM ATP. We found 8 nm forward and backward steps and 5 nm side steps, consistent with on- and off-axes pitches of binding cleft between αβ-tubulin dimers on the microtubule. Probability of the forward step was 1.8 times higher than that of the backward step, and similar to those of the side steps. One-head bound states were not clearly observed, and the steps were limited by a single rate constant. Our results indicate dynein mainly moves with biased small stepping motion in which only backward steps are slightly suppressed.

EFFECTS OF EXERCISE PROGRAM ON COORDINATION AND EXPLOSIVE POWER IN UNIVERSITY DANCE STUDENTS

The aim of this research is to determine the effects of a ten-week modern and recreational dance exercise program and trunk and leg muscle strengthening exercises on the coordination and explosive power of student-age female dancers. The total number of participants was 54, of which 27 made up the experimental group who participated in an experimental exercise program and 27 the control group. The experimental group performed Hip Hop and Dancehall dances and trunk and leg muscle strengthening exercises 3 times a week for 90 min each. The control group had no additional forms of exercise other than regular daily activities. The coordination of the participants was evaluated on the basis of six tests (Side Steps, 20 Steps forward Twirling a Baton, Skipping the Horizontal Jump Rope, Turning in 6 squares, Hand-Foot Drumming and Agility test with a Baton) and two tests for determining explosive power parameters (the squat jump and countermovement jump). Results showed statistical significance between the groups in 5 variables of coordination at the multivariate and univariate level (p&lt;.05, p&lt;.01), and in both variables of explosive power at the univariate level (p&lt;.05). A large and intermediate effect size of the experimental program was determined for 5 variables of coordination, and intermediate effect size for both variables of explosive power. The results of this study showed that a ten-week exercise program for recreational and modern dance and exercises for strengthening the muscles of the torso and legs have a positive effect on the changes in the parameters of coordination and explosive power in student-age female dancers.

The Effect of Basketball Shoe Collar on Ankle Stability: A Systematic Review and Meta-Analysis

Purpose: This review is to systematically estimate if there is any relationship between the shoe collar characteristic and the risk of ankle sprain by reviewing the literature. Methods: Relevant papers were collected through PubMed, ScienceDirect, Google Scholar, and Scopus focused on ankle stability comparison in basketball shoes between high-top and low-top. Articles were involved if they: 1) compared subjects between high-top shoes and low-top shoes, 2) only focused on basketball shoes, 3) utilized kinematics and electromyogram as the primary outcome, 4) published in English. Results: 6 studies were collected in this systematic review, the selecting studies were divided into two different groups based on different motions of test, one of group is a side step cutting task for testing ROM of ankle in coronal plane, another one is conducting a jump task and the peak ankle inversion data at the landing after jump was extracted. Through the meta-analysis combined with a random effect, the model indicated that the type of shoe has no effect on the ankle inversion (p = 0.08) and ROM (p = 0.85). Conclusion: The results showed that there no significant difference in the shoe collar was found. Thus, the more parameters of ankle changes and muscle activity of lower extremity should be assessed in the future to improve our comprehensive understanding for shoe collar effect of ankle stability.

Recent Trends in Physique and Motor Ability of Preschool Children-Trends After 2000 in Japan

The purpose of this study was to clarify the trends since 2000 in body shape, physical strength, and motor ability in early childhood in Japan. The study subjects were kindergarten and nursery school girls (age 3–5 years old) in Aichi Prefecture, Japan. Physique (height and weight), quantitative motor ability (20 m dash, standing long jump, tennis ball throw, side step, one-leg hop, hanging from a horizontal bar, and general motor ability (jump over and under) were compared in the 1999 and 2009 school years. The results revealed that, compared with ten years earlier, height was approximately 0.9 cm shorter in 4-year-old girls and weight was approximately 0.3 kg lighter in 3- and 4-year-old girls in 2009. In physical strength and motor ability, the time for jump over and under was shorter in 3-year-olds, the number of times a rope was jumped was higher and the time hanging from a horizontal bar was longer, and the time for jump over and under was shorter in 4-year-olds. In 5-year-olds, only an increase in the number of times a rope was jumped increased. The tennis ball throw and side steps were not significantly different from 10 years earlier in any of the ages. Physique, physical strength, and motor ability improved with growth, but compared with 10 years earlier many of the items were found to decrease or remain the same in all ages.

Social information affects Canada goose alert and escape responses to vehicle approach: implications for animal-vehicle collisions.

BackgroundAnimal–vehicle collisions represent substantial sources of mortality for a variety of taxa and can pose hazards to property and human health. But there is comparatively little information available on escape responses by free-ranging animals to vehicle approach versus predators/humans.MethodsWe examined responses (alert distance and flight-initiation distance) of focal Canada geese (Branta canadensis maxima) to vehicle approach (15.6 m·s−1) in a semi-natural setting and given full opportunity to escape. We manipulated the direction of the vehicle approach (direct versus tangential) and availability of social information about the vehicle approach (companion group visually exposed or not to the vehicle).ResultsWe found that both categorical factors interacted to affect alert and escape behaviors. Focal geese used mostly personal information to become alert to the vehicle under high risk scenarios (direct approach), but they combined personal and social information to become alert in low risk scenarios (tangential approach). Additionally, when social information was not available from the companion group, focal birds escaped at greater distances under direct compared to tangential approaches. However, when the companion group could see the vehicle approaching, focal birds escaped at similar distances irrespective of vehicle direction. Finally, geese showed a greater tendency to take flight when the vehicle approached directly, as opposed to a side step or walking away from the vehicle.ConclusionsWe suggest that the perception of risk to vehicle approach (likely versus unlikely collision) is weighted by the availability of social information in the group; a phenomenon not described before in the context of animal–vehicle interactions. Notably, when social information is available, the effects of heightened risk associated with a direct approach might be reduced, leading to the animal delaying the escape, which could ultimately increase the chances of a collision. Also, information on a priori escape distances required for surviving a vehicle approach (based on species behavior and vehicle approach speeds) can inform planning, such as location of designated cover or safe areas. Future studies should assess how information from vehicle approach flows within a flock, including aspects of vehicle speed and size, metrics that affect escape decision-making.