Tennis ball cord combined with endoscopy for giant gastric phytobezoar:A case report

BACKGROUND Due to the specificity of Chinese food types,gastric phytobezoars are relatively common in China.Most gastric phytobezoars can be removed by chemical enzyme lysis and endoscopic fragmentation,but the treatment for large phytobezoars is limited,and surgical procedures are often required for this difficult problem.CASE SUMMARY For giant gastric phytobezoars that cannot be dissolved and fragmented by conventional treatment,we have invented a new lithotripsy technique(tennis ball cord combined with endoscopy)for these phytobezoars.This non-interventional treatment was successful in a patient whose abdominal pain was immediately relieved,and the gastroscope-induced ulcer healed well 3 d after lithotripsy.The patient was followed-up for 8 wk postoperatively and showed no discomfort such as abdominal pain.CONCLUSION The combination of tennis ball cord and endoscopy for the treatment of giant gastric phytobezoars is feasible and showed high safety and effectiveness,and can be widely applied in hospitals of all sizes.

Research on the Impact of Core Strength Training on the Motor Skills of Tennis Beginners

With the popularity of tennis in the sports world,more and more beginners are joining this sport.However,for beginners,how to improve motor skills and game performance is still an important issue.Core strength training has potential as a potential adjunct to improve overall fitness and skill in athletes.Therefore,this research aimed to explore the potential impact of core strength training on the motor skills of tennis beginners to provide better training strategies and guidance for coaches and athletes.

“Tennis Xpress”对高校非体育大学生身体素质、技术技能、流畅体验的影响及作用机制研究

运用问卷调查法、教学实验法等主要研究方法,对Tennis Xpress课程背景下的高校非体育专业大学生的身体素质、技术技能掌握和流畅体验情况进行探讨与分析;其目的在于揭示Tennis Xpress教学法在提升非体育专业大学生流畅体验、身体素质和技术技能方面具有更高效率,与此同时揭示流畅体验、身体素质和技术技能三方面的作用机制。结果表明:①“Tennis Xpress”教学模式较传统教学模式更能改善高校非体育专业大学生的身体素质、网球技术技能和流畅体验;②“Tennis Xpress”教学模式提升了教学质量,对于初学网球非体育专业大学生的流畅体验具有积极的作用,利于在高校网球选项课教学中推广与普及;③“Tennis Xpress”教学模式背景下,揭示了流畅体验中“控制感、时间消失感、集中注意力、临场感”四要素与技术技能和身体素质之间的作用机制。研究结论:“Tennis Xpress”教学模式只是众多成功教学方法或模式中的冰山一角,提示广大网球专业教师要围绕“临场感”来设计新教学方法或模式的探究。

Changes in the latencies of visual-evoked potentials in people undergoing tennis training Dynamic comparison before and after 8 weeks training

BACKGROUND： Some previous studies have shown that exercise is an important factor that affects the latencies of visual-evoked potentials （VEPs）. OBJECTIVE： To investigate the effects of spending a period of time undergoing tennis training on the latencies of VEPs by comparing the latencies of VEPs before tennis training with those after 8 weeks of tennis training. DESIGN, TIME AND SETTING： The non-randomly concurrent controlled experiment was performed in the Department of Human Movement Sciences, Physical Education College, Shandong Normal University from April to June 2007. PARTICIPANTS： In total, 45 healthy volunteers from Shandong Normal University were selected as subjects, including 31 students majoring in physical education （11 males and 5 females participated in the tennis training plan for 8 weeks）, and 14 students from other subjects. Informed consent was obtained. According to whether they were majoring in physical education or not, and whether or not they took part in tennis training, the students were divided into 3 groups： a tennis group of physical education students （n = 16） a non-tennis group of physical education students （n =15） and a non-tennis group of non-physical education students （n = 14）. METHODS： The subjects in the tennis group took part in a regular tennis training plan of 2 hours a day and 3 days per week, for 8 weeks, while the subjects in two non-tennis groups were not in the tennis training plan The NDI-200 neural electricity tester （Shanghai Haishen Medical Electronic Instrument Co., Ltd.） was used to measure VEPs before and after the experiment in all three groups, and to compare the latencies of VEPs recorded before training with those recorded after training. MAIN OUTCOME MEASURES： Comparison of the changes in latencies of VEPs before and after 8 weeks of tennis training. RESULTS： All 45 subjects finished the test and datas from all were included in the statistical analysis. There were no significant differences among all the three groups before tennis training, but the female subjects in each group showed significantly shorter N75 latencies than male subjects of the same group （P 〈 0.05）. Comparing the latencies of VEPs after training with those recorded before training, the N75, P100 and N145 latencies were all found to be significantly shorter than before training in the tennis group （P 〈 0.05）, but the N75, P100 and N145 latencies were unaffected in the two non-tennis groups （P 〉 0.05）; some latencies were even significantly longer than the before-training values. CONCLUSION： Special tennis training for 8 weeks can make the subjects＇ VEP latencies significantly shorter. Thus, VEP latencies can change with tennis training.

Mechanical solution for a mechanical problem:Tennis elbow

Lateral epicondylitis is a relatively common clinical prob lem, easily recognized on palpation of the lateral protu berance on the elbow. Despite the "itis" suffix, it is no an inflammatory process. Therapeutic approaches with topical non-steroidal anti-inflammatory drugs, cortico steroids and anesthetics have limited benefit, as would be expected if inflammation is not involved. Other ap proaches have included provision of healing cytokine from blood products or stem cells, based on the recog nition that this repetitive effort-derived disorder repre sents injury. Noting calcification/ossification of tendon attachments to the lateral epicondyle(enthesitis), dry needling, radiofrequency, shock wave treatments and surgical approaches have also been pursued. Physi ologic approaches, including manipulation, therapeuti ultrasound, phonophoresis, iontophoresis, acupuncture and exposure of the area to low level laser light, ha also had limited success. This contrasts with the benefi of a simple mechanical intervention, reducing the stres on the attachment area. This is based on displacemen of the stress by use of a thin(3/4-1 inch) band applied just distal to the epicondyle. Thin bands are required as thick bands(e.g., 2-3 inch wide) simply reduce mus cle strength, without significantly reducing stress. Thi approach appears to be associated with a failure rateless than 1%, assuming the afflicted individual modifies the activity that repeatedly stresses the epicondylar attachments.

Vision testing method for diameter,roundness and hardness of table tennis ball

Under the premise of fully respecting current national standard of table tennis ball,this paper presents an integrated and effective method for testing diameter,roundness and hardness of table tennis ball based on vision measurement. Firstly,camera calibration is performed by 40 mm gauge block to capture the images of table tennis ball in static and pressed state in an appropriate lighting condition. Then image binarization and extraction of image contour are carried out. The least square method is used to fit its center. Finally,the diameter,roundness and hardness are calculated. The measurement data are analyzed by using the method presented in this paper for table tennis ball with known parameter data and with unknown parameter data. Experimental results show that this method can improve measurement accuracy and provide a technical basis for the online testing and integration measurement of table tennis ball.

Correlation analysis of national elite Chinese male table tennis players’ shoulder proprioception and muscle strength

BACKGROUND Shoulder is the most injured part in table tennis players,and it takes multiple roles in transmitting power and striking the center of the ball during the stroke.Proprioception is strongly correlated with high level of athletic performance.It is customary to assume that there is a correlation between proprioception and muscle strength and therefore proprioceptive assessment and rehabilitation is often neglected.AIM To investigate the correlation between isokinetic muscle strength and proprioception in the internal and external rotation muscle groups of elite Chinese male table tennis players,to provide reference for physical training and rehabilitation of elite table tennis players.METHODS A total of 19 national elite table tennis players from the Chinese National Table Tennis Team were recruited in this research.All of them had more than 10 years training experience and had participated major competitions such as the National Games and World Youth Championships.IsoMed 2000 was used to test the peak torque of internal and external rotation isokinetic concentric contraction of the athletes'bilateral shoulder joints at low speed(60°/s)and high speed(180°/s)respectively;IsoMed 2000 was used to conduct the Joint Position Reproduction test to evaluate the athletes'proprioceptive ability capacity at low speed(60°/s)and high speed(180°/s)respectively.If the data satisfied the normal distribution,the correlation between the differences in peak torque s and angles in different directions was analyzed using a Pearson simple linear model;otherwise,Spearman correlation analysis was used.The comparison of proprioceptive ability between the table tennis racket-holding hand and non-racket-holding hands was performed using independent samples t-test if the data satisfied a normal distribution;otherwise,the Mann-Whitney U test was used.RESULTS There was no direct linear correlation between the strength and proprioceptive correlation analysis at slow speed(60°/s)and fast speed(180°/s)in the racket-holding hand;At the slow speed(60°/s)and fast speed(180°/s),there was no correlation between muscle strength and proprioception in the non-racket-holding hand except for the internal rotation variable error(VE)and external rotation relative peak torque,which showed a moderate positive correlation(r=0.477,P<0.05),(r=0.554,P<0.05).The internal rotation’s constant error(CE)and VE were 1.06±3.99 and 2.94±2.16,respectively,for the racket-holding hand,and-3.36±2.39 and 1.22±0.93,respectively,for the non-racket-holding hand;the internal rotation’s CE,VE of the racket-holding hand was lower than that of the non-racket-holding hand,and there was a highly significant difference(P<0.01).CONCLUSION There was no correlation between muscle strength and proprioceptive function in the internal and external rotation of the racket-holding hand’s shoulder in elite Chinese male table tennis players.These results may be useful for interventions for shoulder injuries and for the inclusion of proprioceptive training in rehabilitation programs.

网球进校园背景下Touchtennis运动进校园路径探析

Touchtennis运动是衍生于网球的一种新兴运动项目与网球运动相似并且具有自己的特点,其简单易上手,持续回合多,具有极佳的健身娱乐性,并且其竞技性比肩网球。通过文献资料法、逻辑分析法对该运动项目的自身特点结合网球进校园背景下进行分析,以Touchtennis推广进校园融入学校体育中的可行性以及发展路径进行研究。得出以下结论;Touchtennis场地设施需求较低,和现有学校场地具有极佳的兼容性,而且动作技术简单。由于采用了8cm直径的海绵球,学生练习过程中具有极佳的安全性;其观赏性、娱乐性不输于网球,并且具有极高的竞技性。因此,该项运动在中小学的推广极具价值。

A.I.Tennis App在高校网球训练中的应用

A.I.Tennis App是一款专门针对网球运动开发的一种人工智能软件,特别适合在业余网球练习、学校网球教学以及网球运动队训练中推广应用。采用文献法对A.I.Tennis App、人工智能、网球训练方法以及高校网球训练等相关的文献进行梳理,为本文的撰写提供理论支撑;运用逻辑分析法对A.I.Tennis App的基本特性和高校网球训练方法进行剖析,阐述A.I.Tennis App在高校网球训练中所发挥的积极作用,旨在促进高校网球训练方法和训练模式的创新,为高校网球运动队的可持续发展提供理论参考和有益借鉴。

Longitudinal trajectories of athlete burnout among young table tennis players: A 3-wave study

Purpose:The purposes of this study were to examine the trajectories of athlete burnout across a 2-month period characterized by high physical,psychological,and social demands to explore(1)whether several subgroups of athletes representing distinct burnout trajectories emerged from the analyses and(2)whether athlete burnout symptoms(reduced accomplishment,sport devaluation,and exhaustion)developed in tandem or whether some burnout dimensions predicted downstream changes in other dimensions(causal ordering model).Methods:One hundred and fifty-nine table tennis players in intensive training centers completed a self-reported athlete burnout measure across 3 time points within a 2-month period characterized by high demands.Data were analyzed through latent class growth analysis.Results:Results of latent class growth analysis showed 3 distinct trajectories for each athlete burnout dimension,indicating not only linear or quadratic change but also stability in longitudinal athlete burnout perceptions.Results also suggested that the 3 dimensions of athlete burnout did not develop in tandem.Rather,the likelihood of belonging to particular emerging trajectories of sport devaluation and physical/emotional exhaustion was significantly influenced by the athletes’perception of reduced accomplishment assessed at Time 1.Thus,reduced accomplishment predicted downstream changes in the 2 other athlete burnout dimensions.Conclusion:As a whole,these results highlighted that the multinomial heterogeneity in longitudinal athlete burnout symptoms needs to be accounted for in future research.

Improved sweat gland function during active heating in tennis athletes

Background：Relatively few studies on the peripheral sweating mechanisms of trained tennis athletes have been conducted.The purpose of this study was to compare the sweating capacities of tennis athletes against untrained subjects（controls）.Methods：Thirty-fi e healthy male volunteers participated including 15 untrained subjects and 20 trained tennis athletes（nationally ranked）.Active heat generation was performed for 30 min（running at 60%VO2max） in a climate chamber（temperature,25.0°C ± 0.5°C;relative humidity,60% ± 3%,termed active heating）.Sweating data（local sweat onset time,local sweat volume,activated sweat glands,sweat output per gland,whole body sweat loss volume） were measured by the capacitance hygrometer-ventilated capsule method and starch-iodide paper.Mean body temperature was calculated from tympanic and skin temperatures.Results：Local sweat onset time was shorter for tennis athletes（p〈0.001）.Local sweat volume,activated sweat glands of the torso and limbs,sweat output per gland,and whole body sweat loss volume were significant y higher for tennis athletes than control subjects after active heating（p〈0.001）.Tympanic and mean body temperatures were lower among tennis athletes than controls（p〈0.05）.Conclusion：These results indicate that tennis athletes had increased regulatory capacity of their sweat gland function.

Testing method for veer of table tennis ball

Under the premise of fully respecting Technical Leaflet T3developed by the International Table Tennis Federation(I T T F),this paper proposes an effective method for testing the veer degree of the table tennis ball based on airflow suspension and machine vision.By sequentially capturing the images of the ball in the stable state of spinning and suspension,a set of fitting circle centres from different circular sections can be obtained by circle fitting through the least square method.The minimum circumscribed circle(MCC)diameter of these centres is served as a basic parameter to evaluate the veer degree of the ball.Experimental results show that this diameter can effectively reflect the veer degree of the ball.The method proposed in this papercan provide a technical basis for the veer online testing of the table tennis ball.

Effectiveness of a Single High Dose of Platelet-Rich Plasma (PRP) Injection Over Corticosteroid and Hyaluronic Acid Injections on Osteoarthritis, Chronic Tendinitis and Tennis Elbow Treatment

Background: Corticosteroid, hyaluronic acid (HA) injections and Anti-inflammatory agents are considered as non-invasive treatments for knee osteoarthritis (OA), Chronic Tendinitis (CT) and Tennis elbow (TE) that are supposed to provide symptomatic relief and to help surgical delay intervention. Platelet rich plasma (PRP) is a biological component shown to be beneficial for different orthopedic dysfunctionalities treatment. The presence of GFs in PRPs such as transforming growth factor-β, insulin-like growth factor 1co-stimulate the mesenchymal stem cells and fibroblasts secretions and promotes the fibrin matrix formation which effectively drive the healing process, induces regenerative response and lead to the damage structure repair in orthopedics trauma. Methods: Three groups of a total of 30 patients presenting OA, CT and TE diagnosis, non-responding to corticosteroid, HA and non-steroid anti-inflammatory treatments were randomized to undergo one intra-articular injections of single high dose of PRP. The efficacy of Intra-articular PRP Injections was evaluated before the injection and one month after. The efficiency assessment score was based on [1] Knee injury and Osteoarthritis Outcome Score, [2] Physical Function Short Form (KOOS-PS) Arabic (KSA) version LK 1.0, [3] HOOS-Physical Function Short form (HOOS-PS), and [4] Macdermid patient-rated Tennis Elbow. Results: A significant reduction of pain and a marked improvement in movements was observed in the 3 patient’s groups, PRP-injected patients showed significantly higher values compared with baseline: (p < 0.005 vs baseline), improve functional status and reduce clearly the articular dysfunctions over the time. In our study, single High dose injection of PRP provided an overall superior clinical improvement compared with HA and corticosteroid treatments over the time and the different follow-up checkpoints of the study.

The Effect of Deep Friction Massage versus Stretching of Wrist Extensor Muscles in the Treatment of Patients with Tennis Elbow

Overuse injuries of the elbow and forearm are very common in athletes. This study was conducted to evaluate the effect of muscle stretching and deep friction massage with using wrist joint support during management of tennis elbow. This study included forty patients with tennis elbow divided into two equal groups: the first group with a mean age 38.1 ± 0.294 followed a physical therapy program in form of deep friction massage on the proximal attachment of wrist extensor muscles, the second group with a mean age 37.6 ± 0.253, submitted to stretching exercises of wrist extensors. Both of groups submitted to ultrasonic therapy with wrist splint during treatment period, three sessions per week for six weeks. Outcome measures were universal goniometer, visual analogue scale, and squeezing sphygmomanometer. The results showed that there was a significant improvement in ROM of wrist flexion and wrist extension, and handgrip in second group and it was more than in the first group while no significant difference in pain. This study showed that stretching exercise is more beneficial in the management of patients with tennis elbow.

Analysis of the Duration and Rest Time of Wheel Chair Para Table Tennis at the Rio 2016 Paralympic Games

The purpose of this study was to analyse and compare the match characteristics of wheelchair PTT （Para table tennis） classes that played in the team tournament at the Rio 2016 Paralympic. Eight PTT matches of each selected class （1, 2, 4 and 5） were analysed.The variables analysed were DR （duration of rally） and RT （rest time）. In observing the characteristics of the matches in Classes 1, 2, 4 and 5, the DR corresponded to 3.4 ± 1.2, 4.2 ± 1.5, 4.5 ± 1.6 and 5.2 ± 1.2 seconds, and RT to 13.8 ± 3.5, 14 ± 3.5, 13.3 ± 3.1 and 12.3± 3.3 seconds. In Classes 1 and 2, significant differences in DR were found, but none in RT （p 〉 0.05）. In the DR and RT of classes 4 and 5 there were significant differences （p 〈 0.05）. The results indicated that the DR in Classes 1 and 2 were different because of sitting balance due to severe reduction of function in Class 1 playing arm, interfering in the rally and rest. In Classes 4 and 5 the differences in DR and RT were caused by little sitting balance in Class 4. These characteristics should be used by coaches to check the disadvantages that Class 1 presents against Class 2, and the physical limitations of Class 4 that can directly influence DR in the team tournament against athletes with normal trunk muscle function （Class 5）. Planned training prescriptions between classes would aim at achieving better sport performance in training and team tournaments.

The Impact of Developing Coordination Abilities on the Skill Abilities for Table Tennis Iuniors

The coordination abilities are closely related to the development of technical motor skills, where the player cannot master the technical skills in the special activity, in case lack of special coordination abilities for this activity. Many of table tennis experts agree on that the special coordination abilities for table tennis include each of： （1） the motor adaptation and adjustment ability; （2） the ability to differentiate; （3） reaction speed ability; （4） orientation ability; （5） balance ability; （6） coupling ability; and （7） the ability to sense the rhythm. The aim of this study is to design a training program to develop the special coordination abilities of table tennis and identify the impact of this program on the general skill ability for table tennis juniors. The researcher used the experimental method in two groups： One group is experimental group and another is the control group. The most important result of this study was the training program led to the improvement of the special coordination abilities of table tennis for the experimental group, which led to higher levels of the general skill ability in table tennis for the experimental group more than the control group.

掌中大满贯 N-Gage QD专用游戏“Virtua Tennis”评测

在游戏玩家眼中，世嘉出品的“Virtua Tennis”绝对是值得尊敬和喜爱的游戏。此游戏的闻名在于玩家做出漂亮的挥拍击球动作并不需要复杂的操作。操作简单、易上手是“Virtua Tennis”博得玩家喜爱的原因之一。“Virtua Tennis”最初只是作为PS2／PC游戏推出。逐渐扩展至其他平台之上。N—Gage手机平台便是其中之一，与其他平台一样“Virtua Tennis”在N-Gage QD手机之上同样也拥有良好的口碑。游戏包括两个模式，标准比赛和世界巡回赛，且可以通过蓝牙无线技术支持4人同时进行对抗赛。相信喜欢网球的朋友一定会爱上这个游戏。

The impact of the new composite material technology on the performance of the tennis rackets

With the continues improving of people＇s living standards, more and more people work out in all kinds of sports fields beyond the busy work. On the other hand, the development of the modem competitive sports also requires that the sports experts should not only strive for the scientific training, but should also pay much attention on the improvement and development of the sports equipment at the same time, which makes the sports equipment market have achieved unprecedented prosperity. This paper introduces the application of the fiber reinforced composite materials in the field of sports equipment, which is described mainly from the advantages of the fiber reinforced composite materials used in sports equipment areas, and from the aspects of the principles of material selection, the product varieties, the application examples and the status.