scholarly journals Using Wearable Inertial Sensors to Estimate Kinematic Parameters and Variability in the Table Tennis Topspin Forehand Stroke

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Ziemowit Bańkosz ◽  
Sławomir Winiarski

The study examined kinematic parameters and their inter- and intrasubject variability in the topspin forehand of seven top-level table tennis players. A wireless inertial measurement unit (IMU) system measured the movement of the playing hand to analyze the Ready position, Backswing, and Forward events, and a racket-mounted piezoelectric sensor captured the racket-ball Contact. In a four-phase cycle (Backswing, Hitting, Followthrough, and Back to Ready position), body sensors recorded the cycle and phase duration; angles in the sagittal plane at the shoulder, elbow, and wrist of the playing hand and at the knee joints; and acceleration of the playing hand at the moment of racket-ball contact. The coefficient of variation (CV) was calculated to determine the variability of kinematic parameters within and between players. The observed variability in stroke time duration was low (CV<20%) indicating constancy. The small-to-medium intraindividual variability of angles (CV<40%) indicates that each player used a broadly repeatable technique. The large intraindividual variability in movement was probably functional (i.e., motor adjustment and injury avoidance). Interindividual and intraindividual variability of knee and elbow angles was low; wrist extension was the most variable parameter (CV>40%) for all tasks, and shoulder joint variability was medium-to-large. Variability in hand acceleration was low (CV<20%). Individual players achieved relatively constant hand acceleration at the moment of contact, possibly because angular changes at one joint (e.g., shoulder) could be compensated for by changes at another (e.g., wrist). These findings can help to guide the teaching-learning process and to individualize the training process.

2009 ◽  
Vol 25 (3) ◽  
pp. 203-209 ◽  
Author(s):  
Rafael F. Escamilla ◽  
Glenn S. Fleisig ◽  
Coop DeRenne ◽  
Marcus K. Taylor ◽  
Claude T. Moorman ◽  
...  

A motion system collected 120-Hz data from 14 baseball adult hitters using normal and choke-up bat grips. Six swings were digitized for each hitter, and temporal and kinematic parameters were calculated. Compared with a normal grip, the choke-up grip resulted in 1) less time during stride phase and swing; 2) the upper torso more opened at lead foot contact; 3) the pelvis more closed and less bat linear velocity at bat-ball contact; 4) less range of motion of the upper torso and pelvis during swing; 5) greater elbow flexion at lead foot contact; and 6) greater peak right elbow extension angular velocity. The decreased time during the stride phase when using a choke-up grip implies that hitters quicken their stride when they choke up. Less swing time duration and less upper torso and pelvis rotation range of motion using the choke-up grip supports the belief of many coaches and players that using a choke-up grip results in a “quicker” swing. However, the belief that using a choke-up grip leads to a faster moving bat was not supported by the results of this study.


2005 ◽  
Vol 30 (5) ◽  
pp. 543-553 ◽  
Author(s):  
Sebastien Libicz ◽  
Belle Roels ◽  
Gregoire P. Millet

While the physiological adaptations following endurance training are relatively well understood, in swimming there is a dearth of knowledge regarding the metabolic responses to interval training (IT). The hypothesis tested predicted that two different endurance swimming IT sets would induce differences in the total time the subjects swam at a high percentage of maximal oxygen consumption [Formula: see text]. Ten trained triathletes underwent an incremental test to exhaustion in swimming so that the swimming velocity associated with [Formula: see text][Formula: see text] could be determined. This was followed by a maximal 400-m test and two intermittent sets at [Formula: see text] (a) 16 × 50 m with 15-s rest (IT50); (b) 8 × 100 m with 30-s rest (IT100). The times sustained above 95% [Formula: see text] (68.50 ± 62.69 vs. 145.01 ± 165.91 sec) and 95% HRmax (146.67 ± 131.99 vs. 169.78 ± 203.45 sec, p = 0.54) did not differ between IT50 and IT100 (values are mean ± SD). In conclusion, swimming IT sets of equal time duration at [Formula: see text] but of differing work-interval durations led to slightly different [Formula: see text] and HR responses. The time spent above 95% of [Formula: see text]max was twice as long in IT100 as in IT50, and a large variability between mean [Formula: see text] and HR values was also observed. Key words: interval training, maximal oxygen consumption, triathletes


2012 ◽  
Vol 182-183 ◽  
pp. 1658-1661 ◽  
Author(s):  
Bi Jian Mao

Table tennis, as one of the most popular sports in China, has grown considerably since its developed in the 19th century in England. The biomechanics of the research methods in many sports has been widely used, for understanding of sports and technology and improve sports played an important role Fast break and curving ball technology is this game’s core technology. In this study, we based on fast break and curving ball features of kinematic to reveal the table tennis forehand techniques. Eight male volunteers were participated in this tests, the speed of the racket during the playing was recorded through Vicon Motion Capture System. The action was divided into three major phases: back swing, attack and follow through. At the end of back swing stage, break and curl technologies, the speed parameter shows some differences. While the peak speed in ball contact frame, the speed of curling ball was significantly higher than the fast break. Further study could be carried out in detailing analysis at sub-stage of the action for integral considering.


2012 ◽  
Vol 166-169 ◽  
pp. 3106-3109 ◽  
Author(s):  
Bi Jian Mao

Ping Pong has been considered as one of the most popular sports in the world. Fast break and curving ball technology is this game’s core technology, it will be very important to deeply understand this through biomechanical study. In this research, we based on fast break and curving ball features of kinematic to reveal the table tennis forehand techniques. High speed motion analysis was recorded from eight male subjects. The action was divided into three major phases: back swing, attack and follow through. At the end of back swing stage, break and curl technologies, the speed parameter shows some differences. While the fastest speed in ball contact frame, the speed of curling ball was significantly higher than the fast break. Further study could be carried out in detailing analysis at sub-stage of the action for integral considering.


2013 ◽  
Vol 7 (1) ◽  
pp. 35-42
Author(s):  
Tomáš Gryc ◽  
František Zahálka ◽  
Tomáš Malý

When the golf swing is involving all body segments and is thus considered as one of the most complex of sports motions. The aim of this study was to determine the selected kinematic parameters of movement of pelvic and segments of the upper body (shoulder rotation, hip rotation, X-Factor, stretch X-Factor) that affect the club head speed at ball contact in elite golfers. To build the upper body segment model were used spots and their position during the measurement was scanned by 3D kinematic analyzer CODA Motion System. To determine the interindividual stability of performance the coefficient of variation was used and for statistical analysis of the relationship between kinematic and temporal parameters and the club head speed at ball contact the Pearson's correlation coefficient was used. We found a high interindividual stability in maximized shoulders rotation and club head speed at ball contact parameters. When analyzing relationship between the club head speed at ball contact and the observed kinematic parameters of the movement of the upper body only a high relationship with the stretch X-factor parameter was found.


Sensors ◽  
2021 ◽  
Vol 21 (24) ◽  
pp. 8303
Author(s):  
Jia-Wen Yam ◽  
Jing-Wen Pan ◽  
Pui-Wah Kong

To better understand the biomechanics of para-table tennis players, this study compared the shoulder, elbow, and wrist joint kinematics among able-bodied (AB) and wheelchair players in different classifications. Nineteen participants (AB, n = 9; classification 1 (C1), n = 3; C2, n = 3; C3, n = 4) executed 10 forehand and backhand topspin drives. Shoulder abduction/adduction, elbow flexion/extension, wrist extension/flexion, respective range of motion (ROM), and joint patterns were obtained using inertial measurement unit (IMU) sensors. The results showed clear differences in upper limb kinematics between the able-bodied and wheelchair players, especially in the elbow and wrist. For the para-players, noticeable variations in techniques were also observed among the different disability classes. In conclusion, wheelchair players likely adopted distinct movement strategies compared to AB to compensate for their physical impairments and functional limitations. Hence, traditional table tennis programs targeting skills and techniques for able-bodied players are unsuitable for para-players. Future work can investigate how best to customize training programs and to optimize movement strategies for para-players with varied types and degrees of impairment.


Author(s):  
Ziemowit Bańkosz ◽  
Sławomir Winiarski ◽  
Ivan Malagoli Lanzoni

Background: The identification of gender differences in kinematics and coordination of movement in different body segments in sports may improve the training process by emphasizing the necessity of its differentiation, and consequently individualization, developing, and improving the technique in women and men. Indicating differences can also help in determining the risk of injury in order to prevent from them by diversifying training programs. However, there is no information regarding this problem in the existing literature pertaining to table tennis. Therefore, the aim of the study was to evaluate the differences in the values of selected angular and kinematic parameters during topspin forehand and topspin backhand shots between male and female table tennis players. Methods: Six male and six female advanced table tennis players performed topspin forehand and topspin backhand shots, both receiving a backspin ball. The angular parameters in four events (ready position, backswing, maximum acceleration, and forward) at chosen joints as well as the maximal acceleration of the playing hand were measured, using the myoMotion system, and were compared between male and female players. Results: Significant differences (p ≤ 0.05) were found in the magnitude of angular parameters and maximum hand acceleration between men and women. The movement pattern of topspin strokes performed by men takes into account, more than that in the case of women, movements that use large muscle groups and large joints (hip joints, trunk joints, shoulder joints in extension, and flexion). The difference in the values of maximal acceleration reached almost 50 m/s2 in topspin forehand (p < 0.01) and 20 m/s2 in backhand (p < 0.01). Conclusions: Differentiation of movement patterns can be a manifestation of movement optimization due to anthropological differences and limitations. The differences in the values of maximal acceleration suggest that women could use both sides to perform a topspin attack against the backspin ball, while men should seek opportunities to make a stronger shot with a forehand topspin.


2021 ◽  
Vol 11 (11) ◽  
pp. 5178
Author(s):  
Ivan Malagoli Malagoli Lanzoni ◽  
Sandro Bartolomei ◽  
Rocco Di Michele ◽  
Yaodong Gu ◽  
Julien S. Baker ◽  
...  

The present study aims to assess the position of the racket, and racket height with respect to the floor, during the table tennis top spin stroke. A stereophotogrammetric system (Smart-D, BTS, 8 cameras, 550 Hz) was used to track the table tennis racket during cross-court (CC) and long-line (LL) shots. Ten national level players completed ten CC and ten LL top spin strokes responding to a robot machine. The racket motion throughout the shot showed specific technical characteristics: the minimum height of the racket was detected during the backswing phase; racket height at the end of backswing phase (maximal distance racket/table) was higher than the minimum; height at the racket maximum velocity (ball/racket impact) was greater than the net’s height. Furthermore, the maximum height of the racket occurred at the end of the forward swing. No differences in these kinematic variables between CC and LL were found. Conversely, a higher inclination of the racket at the moment of maximum speed was detected in LL vs. CC. From a practical perspective, the present findings suggest that table tennis players need to introduce specific exercises in order to increase the height of the racket during the forehand top spin stroke, to improve its effectiveness.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Ziemowit Bańkosz ◽  
Sławomir Winiarski

The research is aimed at comparing the kinematics (the movement pattern in the most important joints and accelerations of the playing hand) between female table tennis players coached in Poland (POL) and China (CHIN) during the performance of a topspin backhand stroke (so-called quick topspin). The study involved six female table tennis players at a high sports skill level, playing in Poland’s highest league. Three were national team members of Poland (age: 20.3 ± 1.9 ), while the other three were players from China (age: 20.0 ± 0.0 ). Kinematics was measured using MR3 myoMuscle Master Edition system—inertial measurement unit (IMU) system. The participants performed one task of topspin backhand as a response to a topspin ball, repeated 15 times. Statistical parametric mapping (SPM) was calculated using SPM1D in a Python package that offered a high-level interface to SPM1D. The SPM method allowed for the determination of differences between the Chinese and Polish female athletes. The differences found are probably mainly due to differences in the training methodologies caused by different coaching systems. The observed differences include, among others, greater use of the so-called small steps in order to adapt and be ready during the back to ready position and backswing phases, which gives the CHIN players slightly better conditions for preparation for the next plays. The CHIN players’ position compared to that of the POL players favours a quicker transition from the backhand to the forehand play. This difference is probably related to the difference in the dominant playing styles of the groups studied. Despite the differences in movement patterns in both groups, the exact value of playing hand was achieved. This may be a manifestation of the phenomenon of equifinality and compensation. All the differences found are probably mainly due to differences in the training methodologies caused by different coaching systems.


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