소프트볼 타자의 타격 수행 시 숙련성에 따른 시각탐색 전략 및 선구안 능력 차이

Background and purpose: Knee injuries are common among female softball players, and the stability of the lower extremities and the strength of the knee are essential factors for them. The purpose of this study was to investigate the effect of Kinesio taping with squat exercise (KTSE) on lower extremity muscle activity, muscle strength, muscle tone, and dynamic stability of softball players. Methods: In this study, 40 softball players were randomly assigned to the KTSE group and sham taping with squat exercise (SKTSE) group. All subjects were tested three times a week for 6 weeks, i.e., for a total of 18 times. To evaluate the lower-extremity muscle activity, muscle strength, and muscle tone of the lower extremities, as well as dynamic stability, we used Noraxon Mini DTS, a digital muscular meter from JTech Medical, MyotonPRO, and the side hop test (a clinical evaluation method), respectively. These items were measured before the experiment and 6 weeks after the start of the experiment. Results: Both groups showed significant differences in lower-extremity muscle activity, muscle strength, muscle tone, and dynamic stability (p < 0.05). After the experiment, significant effects on lower-extremity muscle activity, muscle strength, muscle tone, and dynamic stability were observed in the KTSE group compared with in the SKTSE group (p < 0.05). Conclusions: KTSE did not have a negative effect on all items of the functional performance test. KTSE improved lower-extremity muscle activity, muscle strength, muscle tone, and dynamic stability.

Vision is arguably our premier navigational aid, allowing us to map out and actively explore our surroundings. However, we view the world from a constantly shifting platform and some visual mechanisms function optimally only if the images on the retina are reasonably steady. As we go about our everyday activities, visual and vestibular mechanisms help to stabilize our gaze on particular objects of interest by generating eye movements to offset our head movements. The general picture that has emerged of gaze stabilization in primates during motion is of two vestibulo-ocular reflexes, the RVOR and TVOR, that compensate selectively for rotational and translational disturbances of the head, respectively, each with its own independent visual backup mechanisms. A major objective of this chapter is to review recent work on low-level, pre-attentive mechanisms that operate with ultra-short latencies and are largely independent of conscious perception. Recent advances in the field of robotics and, particularly, in the domain of active vision, provide a complementary view of the uses and associated problems of visuo-inertial integration for the stabilization of gaze. Much like biological systems, robots have to comply with physical constraints imposed by the environment and/or by the need to coordinate their sensori-motor components in an efficient way. In contrast with biological systems, however, the experimental variation of implementation parameters and control strategies allows, among other things, a comparison of the different hypotheses and implementations. The goal of this chapter is to draw parallels between the results from biology and from a robot which uses inertial and visual information to stabilize its cameras/eyes. The Chapter is organized as follows. Section 2 describes the peculiarities of the patterns of retinal motion (optic flow) experienced by an observer moving through the environment. The appropriate compensatory eye movements required to stabilize gaze are described in Section 3, introducing the distinction between vergence and version eye movements. Section 4 describes the main characteristics of the vestibular system from a biological and artificial perspective and the distinction between “rotational” and “translational” components of the vestibulo-ocular reflex (VOR). The magnitude of the eye movements required for complete compensation depends on various kinematic parameters such as the position of the eyes in the head, the inter-ocular distance, as well as the distance to the fixation point. Section 5 deals with the integration of visual and inertial information for gaze stabilization. This Section builds upon the concept of “translational” and “rotational” components of the VOR and highlights the differences between “version” and “vergence” control of compensatory eye movements. In particular the role of the radial component of optical flow in the feed-forward control of eye movements is compared with the feed-back loop mediated by binocular disparity. In Section 6, the contribution of inertial and visual information in gaze stabilization is discussed with reference to the different latencies and processing power required by the two modalities. The advantage of the integration of visual and inertial data is discussed from a biological and robotics perspective in the concluding Section.

In the sport of softball, player ability is assumed to be in part attributed to speed, strength, and agility. As such, a preseason battery of physical performance tests may provide coaches information that may aid in the development of a softball player’s ability. However, information regarding the relationship between basic physical performance tests and player ability is limited. Purpose: To compare a preseason battery of performance tests (speed, strength, and agility) with in-season player performance outcomes to determine if a meaningful relationship existed. Methods: Fifteen varsity level high school female softball players (age: 16.1±1.4 yrs, height: 163.1±5.9 cms, mass: 64.8±8.6 kgs completed a preseason battery of performance tests 8-weeks prior to the season. Tests were performed across two sessions, separated by 48 hours to minimize the effects of fatigue. On day one, the athletes completed strength assessment consisting of the one-repetition maximum bench press (1RM BP) and the 1RM back squat (SQ). On day two, the athletes completed 3 trials of the agility (T-Test) and 3 trials of sprint speed (18.3m) assessments with the best score of the three trials used for analysis. Following the completion of the season, the head coach ranked the athletes on a 0-5 scale in batting average, fielding percentage, runs batted in (RBI), and on base percentage (OBP) accumulating a player ability score (PAS) between 0-20. Pearson correlation coefficients (r) were then calculated between the physical performance scores and the PASs. Results: The correlations were as follows: 1RM BP and PAS (r=0.23), 1RM SQ and PAS (r=0.26), T-Test and PAS (r=-0.41), & 18.3 meter sprint and PAS (r=-0.54). Conclusion: Within the parameters of this study, the relationship between preseason physical performance measures and player ability ranges from low to moderate. As such, coaches should prioritize sport specific skills activities followed by physical conditioning exercise in order to improve player ability in this population. Article visualizations:

Softball is a sport that requires speed, agility, and lower-body power to be successful. Accordingly, strength and conditioning programs have focused on improving speed and lower-body power, which are beneficial to players performing softball-related tasks. The purpose of this study was to determine the correlation between absolute and relative lower-body strength to performance measures among female collegiate softball players. Archived data collected during pre-season performance testing for twenty-one (n = 21) NCAA Division II collegiate softball players was used for this analysis. Measurements included countermovement jump (CMJ), broad jump (BJ), linear speed (LS), 505 test for change of direction speed (COD), and shuttle runs. Absolute lower body strength (ALBS) was measured using a 3-repetition maximum hex-bar deadlift (HBDL) and body weight was used to calculate relative lower body strength (RLBS) of each player. Pearson's correlation coefficients were used to relate measures of lower body strength to each performance test. Significant (p ≤ 0.05) large to moderate correlations were discovered between RLBS and COD (505L: r = −0.59, 505R: r = −.63), 300 yard (yd) shuttle run time (trial 1: r = −0.47, trial 2: −0.50), and lower-body power (CMJ: r = 0.48, BJ: r = 0.52). ALBS was correlated only to the BJ (r = 0.43). The results suggest that relative strength is related more with COD, shuttle run, and lower-body power when compared to absolute strength. Therefore, strength and conditioning professionals should consider measures of RLBS when administering softball specific tests for developing and implementing a successful strength program in collegiate softball.

The patterns of optic flow seen during self-motion can be used to determine the direction of one's own heading. Tracking eye movements which typically occur during everyday life alter this task since they add further retinal image motion and (predictably) distort the retinal flow pattern. Humans employ both visual and nonvisual (extraretinal) information to solve a heading task in such case. Likewise, it has been shown that neurons in the monkey medial superior temporal area (area MST) use both signals during the processing of self-motion information. In this article we report that neurons in the macaque ventral intraparietal area (area VIP) use visual information derived from the distorted flow patterns to encode heading during (simulated) eye movements. We recorded responses of VIP neurons to simple radial flow fields and to distorted flow fields that simulated self-motion plus eye movements. In 59% of the cases, cell responses compensated for the distortion and kept the same heading selectivity irrespective of different simulated eye movements. In addition, response modulations during real compared with simulated eye movements were smaller, being consistent with reafferent signaling involved in the processing of the visual consequences of eye movements in area VIP. We conclude that the motion selectivities found in area VIP, like those in area MST, provide a way to successfully analyze and use flow fields during self-motion and simultaneous tracking movements.

Young EFL learners' processing of multimodal input: Examining learners’ eye movements

Cross sectional. To compare the strength and range of motion of the dominant and nondominant shoulders of adult female amateur tennis players. The secondary purpose of the study was to examine whether there were any differences in the observed relationships between women with a past history of shoulder pain and those with no history of shoulder pathology. Information on characteristics of the shoulder in amateur female tennis players is scarce, as research has concentrated on highly skilled or male players, despite the cumulative prevalence of shoulder pain in this group. Fifty-one female competitive, amateur tennis players (average age, 45 years) were tested bilaterally for shoulder internal/external rotation passive range of motion and isokinetic concentric strength. Shoulder range of motion and strength ratios were comparable between sides. In the dominant arm, the total rotational range of motion was 221 degrees, with an internal to external rotator peak torque ratio of 1.05. External rotator strength was significantly greater in the dominant arm of individuals with no history of pain. Range of motion and strength adaptations widely reported in highly skilled tennis players were not apparent in amateur female players. In assessment and management, clinicians should regard the amateur female tennis player as a separate entity from the highly skilled player.

Walking and turning is a movement that places individuals with Parkinson's disease (PD) at increased risk for fall-related injury. However, turning is an essential movement in activities of daily living, making up to 45% of the total steps taken in a given day. Hypotheses regarding how turning is controlled suggest an essential role of anticipatory eye movements to provide feedforward information for body coordination. However, little research has investigated control of turning in individuals with PD with specific consideration for eye movements. The purpose of this study was to examine eye movement behavior and body segment coordination in individuals with PD during walking turns. Three experimental groups, a group of individuals with PD, a group of healthy young adults (YAC), and a group of healthy older adults (OAC), performed walking and turning tasks under two visual conditions: free gaze and fixed gaze. Whole-body motion capture and eye tracking characterized body segment coordination and eye movement behavior during walking trials. Statistical analysis revealed significant main effects of group (PD, YAC, and OAC) and visual condition (free and fixed gaze) on timing of segment rotation and horizontal eye movement. Within group comparisons, revealed timing of eye and head movement was significantly different between the free and fixed gaze conditions for YAC (p<0.001) and OAC (p<0.05), but not for the PD group (p>0.05). In addition, while intersegment timings (reflecting segment coordination) were significantly different for YAC and OAC during free gaze (p<0.05), they were not significantly different in PD. These results suggest individuals with PD do not make anticipatory eye and head movements ahead of turning and that this may result in altered segment coordination during turning. As such, eye movements may be an important addition to training programs for those with PD, possibly promoting better coordination during turning and potentially reducing the risk of falls.

BackgroundThe 3-point shot plays a significant and pivotal role in the historical context ofbasketball competitions. Visual attention exerts a crucial influence on theshooting performance of basketball players. This study aims to investigate the eyemovement characteristics exhibited by high-level basketball players whileexecuting 3-point shot at varying exercise intensities, as well as explore thecorrelation between these eye movement characteristics and 3-point field goalpercentage.MethodsA total of twenty highly skilled female basketball players were recruited asparticipants for this study. During the experiment, the participants wore an eyetracker to record their eye movement data while executing 3-point shot at varyingexercise intensities (low, moderate, and high). The collected eye movement datawas analyzed using Tobii Pro Lab software. Additionally, the participants’exercise intensity was monitored by wearing Polar Team Pro sensors.ResultsThe average number of fixations during the execution of a 3-point shot at threeexercise intensities exhibited statistically significant differences in the front,bottom, top left, and bottom right. Moreover, notable disparities were observed inthe average fixation duration for the front, bottom, and bottom right. The averagetotal number of fixations and fixation duration in the moderate intensity shotwere comparatively lower than those observed in the low and high intensity shots,while the average number of fixations and percentage of fixation duration on thefront were relatively higher compared to those in the low and high intensityshots. Under varying intensities, there were no significant differences observedin the average number of fixations and the 3-point field goal percentage each AOI;however, a significantly positive correlation was found between the front averagefixation duration and the 3-point field goal percentage.ConclusionDuring the execution of a moderate intensity 3-point shot, the player’s fixationis focused and stable, their information search strategy is efficient, and theirinformation processing is precise. Variations in exercise intensity result inchanges to both the information search strategy and degree of processing. Fixatingon the front has a positive impact on 3-point field goal percentage.

1. Purkinje cell activity was recorded from lobules VI and VII of the cerebellar vermis during the performance of visuooculomotor tasks designed to dissociate the signals related to head, smooth-pursuit eye, and retinal image movements. Task-related modulations in the simple spike discharge rates of 157 cells were observed in three alert monkeys. 2. Of 65 Purkinje cells that were completely tested for all three signals, all exhibited smooth-pursuit eye movement-related activity. An additional vestibular or visual response was observed in 17 and 11% of the cells, respectively. Eye, head, and retinal image velocity signals were all recorded in the same unit in 52% of the Purkinje cells. The responses of 5% of the fully tested cells were associated with changes in the direction of eye, head, and retinal image movement. 3. The observed sensorioculomotor responses were direction selective in 98% of the Purkinje cells. For the Purkinje cells that were fully tested, 60% of the cells exhibited peak discharge rates for ipsilateral and 40% for contralateral eye velocity. Of these Purkinje cells, 45% exhibited eye, head, and retinal image velocity signals with equivalent direction preferences. 4. Of 42 Purkinje cells tested, 88% demonstrated some kinds of interactive responses during combined eye and sensory stimulation. The interaction of eye and head velocity signals has been discussed in a companion paper (38). The modulation in discharge rate observed during tracking in the presence of a random dot background pattern could be predicted from the dissociated responses to smooth pursuit in the dark and to movements of the background pattern during suppression of eye movements. 5. The sensitivity to smooth-pursuit eye velocity averaged 1.4 times the sensitivity to head velocity. In 80% of the Purkinje cells, however, the sensitivity to eye velocity exceeded the sensitivity to head velocity by an average of only 10%. The sensitivity to smooth-pursuit eye velocity averaged 1.6 times the sensitivity to retinal image velocity. 6. An increase in Purkinje cell discharge rate was observed during the open-loop period of the initiation of smooth-pursuit eye movements. This open-loop response was consistent with the presence of a visual signal during ocular pursuit, since these cells were also shown to be responsive to a dissociated retinal image velocity signal. Furthermore, the magnitude of the open-loop response indicated an enhancement of the sensitivity to retinal image velocity when visual information became behaviorally significant.(ABSTRACT TRUNCATED AT 400 WORDS)

Previous studies suggested that eye movements might be one of the factors that static images evoke illusory motion perception. The influence that visual information gives to posture control is also...

In this article, we present the following: a background of visually induced motion sickness (VIMS), the goal of our study, and descriptions of three recent studies conducted by our group on the measurement and analysis of eye movement while viewing movies and the relationship of eye movement with VIMS. First, this study focuses on the relationship between eye movement and motion sickness susceptibility. We investigated the relationship between the motion sickness susceptibility and the frequency of optokinetic nystagmus (OKN) with peripheral viewing. It was revealed that susceptible participants showed a lower OKN frequency under conditions that strongly support the occurrence of OKN than insusceptible participants. Second, this study focuses on the relationship between visual information and postural variation such as visually evoked postural responses (VEPRs). In this study, both eye movement and the center of gravity while viewing a movie were measured. Additionally, we evaluated the difference in the transfer gain of the transfer function (vision as input and equilibrium function as output) due to the type of movie content or way of viewing. The gain for the three-dimensional movie with peripheral viewing exceeded that for the two-dimensional movie with central viewing. Third, this study focuses on eye movement and the application of deep-learning technology. In this study, we classified the eye movement as peripheral or central using a convolutional deep neural network with supervised learning. Then, cross validation was performed to test the classification accuracy. The use of >1-s eye movement data yielded an accuracy of >90%.

Background: The aim of the present study was to assess physiological-biochemical reactions to incremental exercise loads and the levels and development of endurance skills in young male and female team game players. Material/Methods: The study sample comprised 370 soccer, handball, basketball and volleyball players (186 girls and 184 boys) from the Lower Silesian Regional Teams in Poland, aged 14.20 ±1.37 years (boys) and 13.90 ±1.15 years (girls). The exercise test consisted ofthe shuttle run Beep Test for estimation of aerobic fitness. The assessment of endurance skills was based on the length of the covered distance in the Beep Test as well as on measurements of the heart rate (physiological) and blood lactate concentration (metabolic). Results: Among the four studied groups of players a statistically significant improvement in endurance skills was noted in male volleyball players (p ≤ 0.05). Conclusions: Significantly higher levels of endurance skills in young male handball, basketball and volleyball players and in female volleyball players who remained on the regional teams for two consecutive years may be an indication of the players’ proper selection and training. Significant changes in blood lactate concentration in young players, revealed in both cross-sectional and continuous studies, were only noted in male volleyball players. Significant decreases in the heart rate in the cross-sectional study was found only in male handball and basketball players and in female basketball players, whereas in the continuous study only in male handball players. An assessment of young players’ physiological-biochemical reactions on the basis of exercise test results can effectively enhance the optimization of training loads.

ABSTRACTGraphical password composition is an important part of graphical user authentication which affects the strength of the chosen password. Considering that graphical authentication is associated with visual search, perception, and information retrieval, in this paper we report on an eye-tracking study (N = 109) that aimed to investigate the effects of users’ cognitive styles toward the strength of the created passwords and shed light into whether and how the visual strategy of the users during graphical password composition is associated with the passwords’ strength. For doing so, we adopted Witkin’s Field Dependence-Independence theory, which underpins individual differences in visual information and cognitive processing, as graphical password composition tasks are associated with visual search. The analysis revealed that users with different cognitive processing characteristics followed different patterns of visual behavior during password composition which affected the strength of the created passwords. The findings underpin the need of considering human-cognitive characteristics as a design factor in graphical password schemes. The paper concludes by discussing implications for improving recognition-based graphical passwords through adaptation and personalization techniques based on individual cognitive characteristics.

This research investigated the difference in aspects of gaze control between esports experts (Expert) and players with lower skills (Low Skill) while playing the real-time strategy game called StarCraft. Three versions of this game at different difficulty levels were made with the StarCraft Editor, and the gaze movements of seven Expert and nine Low Skill players were analyzed while they played the games. The gaze of Expert players covered a significantly larger area in the horizontal direction than the gaze of Low Skill players. Furthermore, the magnitude and number of saccadic eye movements were greater, and saccade velocity was faster in the Expert than in the Low Skill players. In conclusion, StarCraft experts have a specific gaze control ability that enables them to quickly and widely take visual information from all over the monitor. This could be one of the factors enabling StarCraft experts to perform better than players with lower skills when playing games that require task-switching ability.