Tennis Racquet Research Articles

The Application of "Table Tennis Racquet" Random Skin Flap in the Treatment of Facial Skin Carcinoma.

The repair of facial skin and soft tissue defects remains a clinical challenge. The author introduced a novel "table tennis racquet" random skin flap for wound repair after facial skin cancer excision and discussed its survival mechanisms. A lateral mandibular neck skin flap shaped like a table tennis racquet with no well-known blood vessels at the narrow pedicle was designed in 31 cases to repair tissue defects. Among them, there were 8 cases of skin carcinoma in the frontotemporal area and 23 cases of skin carcinoma in the cheek. The flap area was 8.0 × 7.0 cm at maximum and 3.0 × 2.5 cm at minimum, with a pedicle width of 1.0-2.0 cm and a pedicle length of 2.0-6.0 cm. All 31 "table tennis racquet" random skin flaps survived, although there were 3 cases with delayed healing of distal flap bruising. All of them had an ideal local shape after repair with a concealed donor area and inconspicuous scars. This flap has a "table tennis racquet" shape with a pedicle without well-known blood vessels and has a length-to-width ratio that exceeds that of conventional random flaps, making it unconventional. Because of its long and narrow pedicle, it not only has a large rotation and coverage area but also can be designed away from the defect area, avoiding the defect of no donor tissue being localized near the defect. Overall, this approach is an ideal option for repairing tissue defects after enlarged excision of facial skin carcinoma.

There Is a Lot More to Transplantation Surgery Than the Surgery Itself: The "Other" Sir Peter John Morris, AC, FRS.

There Is a Lot More to Transplantation Surgery Than the Surgery Itself: The "Other" Sir Peter John Morris, AC, FRS.

Pickleball Sound 102 - Time History and Spectral Analysis of Pickleball Sound

The sounds from pickleball have unique time and spectral characteristics. Each time a paddle strikes a ball, a pulse of sound is generated. The loudness of this impact depends on the paddles and balls used, the skill of each player, and the force of each impact. To understand the sound generated by different paddles and balls, a simple anechoic chamber was constructed for testing paddles and balls. A test procedure was created, and a data collection process was implemented. The test chamber was used to measure impact sounds with a constant ball speed. The time history and frequency content of several paddle and ball impacts were measured. The time history and spectral content from different balls and from different paddles varied significantly. These sounds are markedly different from the sounds from a tennis racquet. The measurements show that this test chamber and this test method are good tools for measuring impact sound from pickleball paddles and balls. The measured results can be used to rank paddles based on their noise signatures. These results at a constant speed in a test chamber can also be used to estimate higher sound levels with higher force of impact in game situations.

Characteristic yet unusual presentation of an odontogenic myxoma in the anterior mandible

Odontogenic myxoma (OM) is a rare benign odontogenic tumor characterized by stellate and spindle-shaped cells dispersed in an abundant myxoid extracellular matrix. The bony invasion by the tumor imparts a characteristic ‘soap bubble’, ‘honeycomb’, or ‘tennis racquet’ radiographic appearance to the lesion. The decision of adopting a conservative or radical approach also depends on various factors such as location, size, and duration of the lesion, and age, gender, and expectations of the patient. Therefore, adequate treatment planning is crucial for the management of cases of OM and varies on an individual basis. The present case report described the management of a case of unusually large OM occurring in a 31-year-old Indian female in the mandibular anterior region crossing the midline.

수정 IPA를 이용한 테니스 동호인의 라켓 구매 시 선택속성 분석

Purpose: This study aims to use importance-performance analysis (IPA) of selection attributes in a tennis club member’s purchase to derive the ranking of priority for items that need improvement, to provide basic data that can later be used by businesses related to tennis products or tennis supply stores to efficiently determine or apply marketing strategies.BR Method: A survey was done with 370 tennis club members who play in Psuan tennis clubs. 348 surveys were used in the actual analysis, excluding 22 surveys that weer deemed to be incomplete or not properly done. For data analysis, SPSS Win Ver 26.0 program was used with a statistical significance level set at α.05. To certify the validity and credibility of the survey, factor analysis were done and produced a coefficient of Cronbach’s α. To draw the study result, analysis of frequency, exploratory factor analysis, paired-samples t-test, and revised IPA have been done.BR Results: The findings of the study are as follows. First, when purchasing a tennis racket, the importance ranking for the selection attributes was in the order of weigh, tease of use of technology, and durability. The ranking of achievement was in the order of imported brand, bradn awareness, and luxury brand. Second, as a result of analyzing the difference between the importance and achievement of the selection attribute when purchasing a tennis racquet, it was found that there was a significant difference in all questions except for ‘color’ and ‘shape’ of the design factor. Third, In the Ⅰ quadrant, seven items were included, including ‘weight’, and ‘shape’, In the Ⅱ quadrant, four items were included, including ‘price discount’, and ‘A/S expertise.’ In the Ⅲ quadrant, six items were included, including ‘A/S accessibility’, and ‘A/S period’, In the Ⅳ quadrant, five items were included, including ‘design’, and ‘color.’BR Conclusion: In summary, it is judged that it is necessary to establish a marketing strategy for the selective attributes included in Quadrant II, which are considered important by tennis club members, but with low achievement, and to derive improvement measures to improve the performance.

Biomedical Serious Game System for Lower Limb Motor Rehabilitation of Hemiparetic Stroke Patients.

Hemiparesis resulting from a stroke has a direct impact on patients' daily activities. New approaches for motor rehabilitation include Serious Games (SG) because they include (in a motivating way) the three fundamental elements for rehabilitation: intensive, repetitive and task-oriented training. This study aims to evaluate the therapeutic effects of a biomedical SG and a scoring system developed for lower limb motor rehabilitation of hemiparetic stroke patients. The SG was inspired by the classic videogame called Pong, where the goal is to control a tennis racquet, but using muscular strength. A knee extensor apparatus was adapted with a load cell and mechanical adjustments for measuring the muscular strength of the quadriceps femoris (QFG) and hamstrings (HSG). A scoring system was proposed to evaluate muscular control. Eleven hemiparetic stroke patients participated in an exercise program using the SG twice a week for ten weeks and only the paretic side was trained. Significant Effect Sizes ( d ) were found for QFG strength ( d=0.5;p=0.021 ), QFG control ( ), HSG strength ( d=1.1; p = 0.001 ), HSG control ( d=1.5; p = 0.003 ), functional mobility ( ), gait speed ( d=0.4; p=0.007 ) and motor recovery ( ). Results indicate that the intervention of a SG with both proper apparatus and evaluation system may effectively promote lower limb motor rehabilitation of hemiparetic stroke patients.

Vibration-Damping technology in tennis racquets: Effects on vibration transfer to the arm, muscle fatigue and tennis performance

High vibration transfer from a tennis racquet to the player may cause discomfort, and is hypothesized to influence performance and the onset of muscle fatigue. This study examined a racquet with a novel vibration damping technology (VDT) designed to mitigate frame vibration. Racquet vibration, post-impact vibration transfer to the player, arm electromyographic activity and tennis performance were compared to a non-VDT racquet. Nineteen young adult, competitive tennis players hit forehands and serves until near exhaustion on two days; using one of the two racquets each day. Tri-axial accelerometers mounted to racquet shaft, hand and forearm recorded vibration behaviour. Surface electromyography recorded activity of five arm muscles. In comparison to the non-VDT racquet, the VDT design showed: 1) A significantly lower mean normalised acceleration signal energy at the racquet during unfatigued play (−40%) and at near exhaustion (−34%), which corresponded to a 20–25% lower signal energy at the hand. 2) Reduced signs of arm muscle fatigue at near exhaustion, which was most pronounced in biceps and wrist extensors. 3) Players hit 11% more forehands and placed 40% more hits in the target area at near exhaustion. Conclusion: VDT effectively reduces racquet vibration. Initial evidence indicates that it may delay muscle fatigue, which was associated with increased ball placement accuracy.

The efficacy of urinary continence in patients undergoing radical prostatectomy with bladder neck extension and mucosal eversion reconstruction anastomosis

Objective To discuss the efficacy of urinary continence in patients undergoing radical prostatectomy with bladder neck extension and mucosal eversion reconstruction anastomosis. Methods From August 2016 to November 2018, 31 patients with prostate cancer underwent laparoscopic radical prostatectomy. The patients were 62-85 years old(mean 74.8 years), and the mean PSA score was 16.5 ng/ml(6.8-34.2 ng/ml). The pathological examination confirmed that the Gleason score was 6-9 and the prostate size was 44-83 ml. All patients underwent laparoscopic radical prostatectomy with bladder neck extension and mucosal eversion reconstruction anastomosis. Surgical procedure: After resection of the prostate in laparoscopic radical prostatectomy, the bladder neck was sutured at 6 o'clock position to narrow the bladder neck ( tennis racquet reconstruction). The interval was 1 cm, and 2-3 needles were sutured, the distance between the neck of the bladder and the ureter was extended. The bladder neck mucosa and urethral mucosa eversion were performed. The posterior wall of the bladder neck was sutured at interval of 1 cm on both sides of the midline. After the knot was tightened, the posterior wall of the bladder was folded and bladder neck was elevated. The posterior wall of the bladder and the posterior wall of the urethra were sutured to reduce the distance between the bladder and the urethra. Finally, the bladder and urethra were anastomosed. The postoperative urinary continence recovery and the clinical effect were recorded. Results The operation time of 31 patients ranged from 80 to 210, with an average of 139.7 minutes. Intraoperative bleeding was 50-330 ml, with an average of 144.2 ml. None of the patients switched to open surgery during the operation, and there was no injury to large vessels and rectum, and no anastomotic leakage. Postoperative pathology showed 21 cases of pT2 stage, 10 cases of pT3 stage, 2 cases of positive margin, including 1 case of basal part and 1 case of apex part, both of which received medical castration therapy postoperatively.The surgical margin was positive in 2 cases (6.45%). 31 patients removed the urinary catheter in ten days after surgery. 17 cases (54.8%) recovered instantly urinary continence; 7 cases (22.6%) urinary continence in 1 month after operation; 4 cases (12.9%) urinary continence in 3 months after operation; and 3 cases (9.7%) urinary control in 6 months after operation. One case had urinary retention after removing the urinary catheter, and cathetered for 2 more weeks. After pulling out again, the urinary continence was good. Conclusions Laparoscopic radical prostatectomy with bladder neck extension and mucosal eversion reconstruction anastomosis may be helpful for early recovery of urinary continence. Key words: Prostatectomy; Bladder neck extension; Mucosal eversion; Urinary continence

Quantifying hitting activity in tennis with racket sensors: new dawn or false dawn?

ABSTRACT The non-invasive measurement of movement through sensor technologies is common in elite sport, yet only recently become possible in tennis. This study validated two commercial tennis racquet sensors compared to gold standards in VICON and expert notational analysis. One national-level male tennis player hit 24 shots (9 forehands and 9 backhands, hit with heavy topspin, flat and slice; 6 serves) using a Babolat Play racket with a Zepp sensor. Measures of shot type, impact location and racket speed were compared against those captured by a 500-Hz 12 camera VICON system. Cohen’s kappa (κ) and a weighted kappa (κ w) assessed the accuracy of stroke classification and impact location, respectively, and intraclass correlation coefficients (ICC) validated sensor-derived racket speed. Both sensors recorded the same total stroke volume as VICON, while Zepp racket speed displayed near perfect agreement with VICON (ICC = 0.983; p < 0.001). They exhibited moderate agreement with true stroke classification (Babolat: κ = 0.730; Zepp: κ = 0.612) and minimal agreement with true impact location (Babolat: κ w = 0.412; Zepp: κ w = 0.217). During match play, both sensors achieved near perfect accuracy for stroke volume but experienced difficulty discriminating the different stroke types. In sum, the Babolat Play and Zepp determined stroke volume and intensity accurately but were less effective in identifying specific strokes and impact locations.

Automatic Line Calling Badminton System

A system and relevant method are described to detect whether a projectile impact occurs on one side of a boundary line or the other. The system employs the use of force sensing resistor-based sensors that may be designed in segments or assemblies and linked to a mechanism with a display. An impact classification system is provided for distinguishing between various events, including a footstep, ball impact and tennis racquet contact. A sensor monitoring system is provided for determining the condition of sensors and providing an error indication if sensor problems exist. A service detection system is provided when the system is used for tennis that permits activation of selected groups of sensors and deactivation of others.

A coaches’ perspective on the contribution of anthropometry, physical performance, and motor coordination in racquet sports

ABSTRACTDifferences and similarities between table tennis and other racquet sports exist, but are not well documented in the literature, in spite of the relevance for talent identification. In this study we aimed at identifying the key characteristics of table tennis in comparison with tennis and badminton based upon a survey in coaches. A total of 177 licensed coaches from all across the world and with diverse professional backgrounds completed a survey on anthropometric measures, physical performance, and motor coordination skills. On a scale from 1 to 10, coaches indicated to what extent a talent characteristic was important for their sport. MANOVA identified key differences as well as similarities between all three racquet sports and a subsequent discriminant analysis allocated coaches correctly for table tennis, tennis, and badminton 81.01%, 55.6%, and 71.4% respectively. Our results show that table tennis and other racquet sport coaches are well aware of differences between the racquet sports and also the importance and value of testing and assortment of skill components. These findings can assist coaches in future talent orientation and transfer in racquet sports.

Nonlinear membrane stiffness model of a tennis racquet string bed

The overall stiffness of the string bed of a tennis racquet depends on numerous factors including the size and shape of the string bed, initial string tension, string spacing, and string geometric ...

Tennis Elbow Pathogenesis

Lateral epicondylitis, also known as tennis elbow, is a common pathology that usually affects tennis players and athletes involved in overhead throwing, especially athletes between 30 and 50 years old. It is a painful condition that starts with swelling of the tendons that attach to the lateral epicondyle of the humerus and continues as a tendinosis. This pathology is related to a repetitive contraction of the extensor carpi radialis and it could also be associated with the conditions of the tennis racquet, an improper technique while playing tennis or with the frequency of play. The aim of this review is to analyze the different causes of suffering lateral epicondylitis in tennis players and its pathogenesis.

A Case Of Recurrent Odontogenic Myxoma Of The Mandible: Clinical And Radiographic Diagnosis With Review Of Literature

Odontogenic myxomas are benign tumors of ectomesenchymal origin and comprise of 3%-8% of all odontogenic tumors. They may be derived from cells of the dental follicle, dental papilla or periodontal ligament. Most of the tumors occur in the second to third decades of life and show a marked female predilection. They occur in the premolar-molar region of both jaws but show a preference to the mandible over the maxilla. Radiographically they may be identified due to their characteristic ‘tennis racquet’ appearance although other radiographic forms such as soap-bubble, honeycomb or wispy lace-like trabeculae also exist. Histological appearance of a myxoid stroma made up of 80% hyaluronic acid and 20% chondroitin sulphate with collagen fibres and spindle shaped fibroblasts is distinctive. Owing to the absence of a capsule and the gelatinous nature of the ground substance, a high degree of recurrence is seen especially in tumors that are conservatively managed. Therefore adequate surgical resection with other modes of tissue destruction such as cryotherapy should be followed. Long term follow-up with radiologic surveillance is advocated in order to recognize a possible recurrence and prevent massive tissue destruction and its associated morbidity.

Reliability and Factorial Validity of Non-Specific and Tennis-Specific Pre-Planned Agility Tests; Preliminary Analysis.

Agility is an important quality in tennis, yet there is an evident lack of studies focussing on the applicability of tennis-specific agility performances and comparing them to equivalent non-specific agility performances. The aim of this study was to evaluate the reliability and factorial validity of three tests of pre-planned agility, performed in specific (with a tennis racquet) and non-specific (without a tennis racquet) conditions. The sample consisted of 33 tennis players (13 males and 20 females; age: 18.3 ± 1.1 years and 18.6 ± 1.3 years; body height: 185.4 ± 51 cm and 169.3 ± 4.2 cm, 74.0 ± 4.4 kg and 61.2 ± 3.1 kg, respectively). The variables comprised three agility tests: a 20-yard test, a T-test and the Illinois test, all performed in both specific and non-specific conditions. Between-subject and within-subject reliability were found to be high (Cronbach Alpha: 0.93 to 0.98; Coefficient of Variation: 3 to 8%), with better within-subject reliability and stability of the measurement for specific tests. Pearson’s product moment correlations between the non-specific and specific agility performances were high (r ≥0.84), while factor analysis extracted only one significant latent dimension on the basis of the Guttman-Kaiser criterion. The results of the 20-yard test were better when the test was conducted in the specific conditions (t-test = 2.66; p < 0.05). For the Illinois test, superior results were recorded in the non-specific conditions (t-test = 2.96; p < 0.05), which can be explained by the test duration (about 20 s) and non-specific locomotion forms such as rotational movements. Considering the findings of the present study, when testing tennis-specific pre-planned agility, we suggest using tests of short duration (less than 10 s) and sport-specific types of locomotion.

Tennis Elbow Pathogenesis

Lateral epicondylitis, also known as tennis elbow, is a common pathology that usually affects tennis players and athletes involved in overhead throwing, especially athletes between 30 and 50 years old. It is a painful condition that starts with swelling of the tendons that attach to the lateral epicondyle of the humerus and continues as a tendinosis. This pathology is related to a repetitive contraction of the extensor carpi radialis and it could also be associated with the conditions of the tennis racquet, an improper technique while playing tennis or with the frequency of play. The aim of this review is to analyze the different causes of suffering lateral epicondylitis in tennis players and its pathogenesis.

Scaling Tennis Racquets During PE in Primary School to Enhance Motor Skill Acquisition

Purpose: Research supporting the skill acquisition benefits of scaling sports equipment for children in a real-world setting where child-to-coach ratios are high is scarce. Thus, the aim of this study was to examine the influence of scaling the tennis racquet on children's skill acquisition in a primary school setting. Method: Children aged 6 to 7 years old practiced for 5 weeks during physical education classes using either a small racquet (SR group; n = 23) or a large racquet (LR group; n = 23). Measures of hitting technique, hitting performance, and general hand–eye coordination were administered before and after the practice period. Results: The high child-to-coach ratio (22:2) seemingly led to a small number of practice opportunities for children. Despite this finding, children in the SR group displayed greater improvements in hitting technique for the forehand and backhand. This finding did not translate to better hitting performance (i.e., skill outcome), however, with similar results found for both groups during the pretest and posttest. Conversely, the LR group showed greater improvements in the hand–eye coordination measure of bouncing the ball on the ground. Conclusion: Scaling equipment for children enhanced the acquisition of a more desirable technique in a real-world setting. We speculate that this technique acquisition would also lead to improved hitting performance following a longer practice period, whereby children are exposed to more practice opportunities.

The kinematics of table tennis racquet: differences between topspin strokes.

Studies of shot kinematics in table tennis have not been sufficiently described in the literature. The assessment of the racquet trajectory, its speed and time characteristics makes it possible to emphasize on certain technical elements in the training process in order, for example, to increase strength, speed of rotation or speed of the shot while maintaining its accuracy. The aim of this work was to measure selected kinematic parameters of table tennis racquet during forehand and backhand topspin shots, while considering the differences between these strokes in table tennis. The measurements took place in a certified biomechanical laboratory using a motion analysis system. The study involved 12 female table tennis players in high-level sports training and performance. Each subject had to complete series of six tasks, presenting different varieties of topspin shots. The longest racquet trajectory was related to forehand shots, shots played against a ball with backspin and winner shots. The maximum racquet velocity was precisely in the moment of impact with the ball. The individual of velocity and distance were larger in the direction of the acting force, depending on the individual shot. Changing the type of topspin shot requires changes of time, velocity and primarily distance parameters as well as the direction of the playing racquet. The maximum speed of the racquet occurring at the moment of the impact is probably the most important principle in playing technique. The results can be directly used in improving training of table tennis techniques, especially in the application and use of topspin shots.

The microstructure of a graphene-reinforced tennis racquet

The microstructure of a graphene-reinforced tennis racquet has been analysed using a combination of optical microscopy and Raman spectroscopy. It is shown that the main structural components in the racquet frame are high-strength carbon fibres in an epoxy resin matrix. It is also found that graphene-based nanoparticles are used to reinforce resin-rich regions in the shaft of the racquet at the discontinuity in the fibre tows, where the handle is joined to the racquet head. From a detailed analysis of the relative positions and intensities of the Raman G and 2D bands, it is demonstrated that the nanoparticles employed in the racquet are most probably graphite nanoplatelets which have been added to improve the mechanical properties of the resin-rich regions. The nomenclature used for describing graphene-based materials is also discussed in the context of this present study.

SportsTech: Tennis Racquets

So, Wimbledon is upon us once again, and like so many others I have been inspired to dig my tennis racquet out of the dark recesses of the garden shed, where it generally stays for 11 months of the year. Its chipped and battered frame and straggly strings are a far cry from the state-of-the-art objects that Federer and co will be wielding on Centre Court. With Wimbledon approaching, we show how to keep up with the professionals in the latest tennis racquet technology.