Forehand Stroke Research Articles

Comparison of Open and Closed Stance Forehand Strokes among Intermediate Tennis Players

Background: Nowadays tennis is becoming faster and players are able to hit powerful from virtually anywhere on the tennis court. Training programmers and effective planning will help in designing safe, effective, and productive programs designed to help optimize the tennis performance of players. Objective: This research examine the effectiveness of open and closed stance forehand strokes in terms of percentage of success, accuracy and also to investigate whether there is a relation between level of accuracy and the choice of forehand strokes used by tennis player. Method: Participants were divided into two groups, namely, male and female who learned forehand strokes for one month. The participants were tested by using a two skill test for percentage of success and level of accuracy. Result: Founding showed that the closed stance forehand stroke has far better percentage of success and accuracy among the intermediate tennis players, but the difference was not significant. In addition, male players showed more accuracy and success in this research. And also accuracy did not have any influence to choice of forehand stroke among the intermediate tennis players. Conclusion: This research could improve the training protocol design for teaching the closed stance and open stance strokes. Keywords: Forehand stroke, open stance, closed stance, tennis accuracy, percentage of success

The Effects of Forced Exhalation and Inhalation, Grunting, and Valsalva Maneuver on Forehand Force in Collegiate Tennis Players.

To examine the effects of forced expiration (FE), forced inspiration (FI), grunting (GR), and valsalva maneuver (VM), on air volume, maximum force production, and muscle recruitment during a simulated forehand stroke in collegiate tennis players. Superficial electrodes were placed over the anterior deltoid, pectoralis major, rectus abdominis, lumbar and thoracic erector spinae, and external and internal obliques. Subjects stood in a simulated forehand stroke stance with their dominant hand positioned on a force plate. Subjects performed 3 repetitions of maximal 2- to 3-second isometric forehands with randomly assigned breathing conditions (FE, FI, VM, and GR) and 30-seconds rest between contractions. Air volumes were also collected during each trial. A repeated-measures multivariate analysis of variance compared normalized peak electromyographic activity across the 7 muscle groups. Separate repeated measures ANOVAs compared the effect of breathing conditions on peak force production and air volume. Statistical significance was set at p ≤ 0.05 for all analyses. Overall muscle activity differed significantly by breathing condition (p = 0.031) with greater anterior deltoid activity was seen in FE and GR vs. VM. Internal oblique activity was significantly greater in GR than FI or VM, and thoracic erector spinae activity was significantly greater during FE and VM than FI. Force production did not differ significantly among breathing conditions (p = 0.74); however, GR forces were greater than FI and VM forces (p ≤ 0.05). Forced expiration air volume was significantly greater (p < 0.001) than FI, GR, or VM. These findings suggest that either GR or a more quiescent FE can be used to enhance force production. Forced expiration is a potentially safer alternative to VM and more aurally pleasing than GR.

Changes in ball speed by forehand stroke with take-back action using dorsal-palmar flexion in table tennis

Changes in ball speed by forehand stroke with take-back action using dorsal-palmar flexion in table tennis

Self-talk does not affect the transfer and retention in the tennis forehand learning in beginners

The aim of this study was to investigate the effects of self-talk on motor learning in beginners. The learning task was the forehand stroke in tennis. Eighty-four students were assigned into five self-talk groups and one control group. One of the self-talk groups used four cues for directing attention to key elements of the forehand stroke. The other self-talk groups made use of only one of the four cues (ball, bounce, hit, and ready), and the control group received only general instructions. In the acquisition phase, all groups performed 180 trials over three days. Then they performed a transfer test of 10 trials involving a change in the target direction. After five days they performed a retention test in the same conditions of the acquisition phase. The performance was analysed in terms of rates of success and consistency of the forehand hit to the target located on the opponent’s court. Results showed that all groups improved their performances in the acquisition phase, and that they maintained the improvement in the retention and transfer tests. However, no differences were found between the groups. It was concluded that self-talk did not affect the learning of forehand stroke in tennis. In addition, learning with self-talk with four cues was similar to that with selftalk with only one cue.

The Development of a Methodology to Determine the Relationship in Grip Size and Pressure to Racket Head Speed in a Tennis Forehand Stroke

This study developed a methodology to examine the effects of grip size and grip firmness on the kinematic contribution of angular velocity (KCAV) to the generation of racket head speed during a topspin tennis forehand. The KCAV is subdivided into kinematic contribution of joint angular velocity and kinematic contribution of the body segments in the upper trunk translational and angular velocities. Two Babolat Pure Storm GT rackets, with grip sizes 2 and 4 respectively, were used with Tekscan 9811E pressure sensors applied to the handles to examine pressure distribution during the stroke. Upper body kinematic data taken from the racket arm and trunk were obtained by means of a Vicon motion capture system. One elite male tennis player was recruited. Fifty topspin forehand strokes per grip at two nominal grip pressures were performed in a laboratory environment with balls being tossed towards the player and struck on the bounce towards a target on a net in as consistent a way as practically achievable.Processing of the results showed that the firm grip condition led to a significant (p<0.001) increase in average racket head speed compared to a normal grip condition. The normal gripping condition resulted in a significant (p<0.001) increase in average racket head speed for grip size 2 compared to grip size 4. A trend in negative linear relationships was found between upper trunk and shoulder joint in KCAV across conditions. Using the smaller grip also led to a trend in negative linear relationship between shoulder joint and wrist joint in KCAV across grip conditions. Grip pressure for grip size 2 showed the same pattern across gripping conditions. From 50-75% of completion in forward swing, the pressure difference due to grip firmness decreased. This feasibility study managed to quantify the KCAV while performing a topspin forehand, with respect to changing of grip size and grip pressure in an elite male tennis player for the first time.

Effects of racket weight distribution on forehand strokes in tennis

"Effects of racket weight distribution on forehand strokes in tennis." Computer Methods in Biomechanics and Biomedical Engineering, 18(sup1), pp. 2044–2045

테니스 포핸드 스트로크 시 스윙타입과 스탠스 형태에 따른 라켓움직임 관한 비교분석

테니스 포핸드 스트로크 시 스윙타입과 스탠스 형태에 따른 라켓움직임 관한 비교분석

Robustness to temporal constraint explains expertise in ball-over-net sports

The present study investigated motor expertise in interpersonal competitive ball-over-net sports in terms of a dynamical system with temporal input. In a theoretical framework, the behavior of the system is characterized by a fractal-like structure according to switching input, which changes uniquely according to the duration of input and internal parameter of the system. We investigated periodic movements, in which the player executed a forehand or backhand stroke repeatedly, and continuous switching movements, in which the player continuously switched between two movement patterns corresponding to hitting the ball under two ball directions and with six temporal constraint conditions during a table tennis rally. In the periodic movement, we observed two limit-cycle attractors corresponding to each direction in the phase space independent of temporal constraint or skill level. Conversely, in the continuous switching movement, a transition in trajectories between the two limit-cycle attractors was observed in the phase space, and this transition was characterized by a fractal-like structure. The fractal-like structure moved closer to the random structure as temporal constraint increased independent of skill level. However, the temporal constraint condition closest to the random structure was higher for the advanced players than for the novices, indicating that robustness to the temporal constraint was higher for the advanced players than for the novices. Our results suggest that motor expertise in interpersonal competitive ball-over-net sports is more robust to temporal constraints with various inputs.

Body segments cooperation during forehand stroke production in young and adult tennis players

Zusa, A., Lanka, J., Vagin, A., & Cicchella, C. (2015). Body segments cooperation during forehand stroke production in young and adult tennis players J. Hum. Sport Exerc., 9(Proc1), pp.S161-S168. The purpose of the study was to investigate biomechanical characteristics of the forehand stroke production in adult and young tennis players, such as body segments cooperation, separation angle (x-factor) and max speed of a racquet. Kinematic data was collected with an optoelectronic motion capture system Qualisys. Participants in the experiment were 6 mid-level adult tennis players (age 19.5 ± 2.3 years, weight 66.8 ± 7.7 kg, height 170.5 ± 7.8 cm, sports experience 13.2 ± 1.7 years) and 4 young tennis players (age 11 ± 0.6 years, weight 43.5 ± 4.8 kg, height 156.3 ± 4.8 cm, sports experience 5 ± 0.5 years). The task of the motion was to carry out 3 forehand strokes for 3 times, the position of the feet and type of stance was not regulated. Results showed that racquet speed during forehand follow through phase, is significantly higher in adult players. Adult athletes have significantly higher x-factor values, which indicates that they more effectively implement muscle-tendon complex pre-stretching principle during backswing and forward swing phase. As well as adults, young tennis players also perform principle of sequential action of body segments during the stroke production, according to their technical skills and level of training. Key words: KINEMATICS, XFACTOR, MUSCLE-TENDON COMPLEX PRE-STRETCHING, MAX SPEED OF A RACQUET, BODY SEGMENTS INTERACTION.

A study on a method of coaching of forehand stroke of badminton

A study on a method of coaching of forehand stroke of badminton

The effects of "grunting" on serve and forehand velocities in collegiate tennis players.

The aim of this study was to examine the effects of grunting on velocity and force production during dynamic and static tennis strokes in collegiate tennis players. Thirty-two (16 male and 16 female) division II and III collegiate tennis athletes with a mean age of 20.2 ± 1.89 years participated as subjects. Demographic and survey data were obtained before subjects completed a 10- to 15-minute warm-up of serves and ground strokes while grunting and not grunting. The subjects performed randomized sets (3 grunting and 3 nongrunting trials) of serves and forehand strokes both dynamically and isometrically. Stroke velocities and isometric forces were measured with a calibrated radar gun and calibrated dynamometer, respectively. Electromyographic (EMG) data from subjects' dominant pectoralis major and contralateral external oblique muscles were recorded and averaged for data analysis. A repeated measures multivariate analysis of variance (RM-MANOVA) compared dynamic stroke velocity, isometric muscle force, and peak EMG activity during each breathing condition at the 0.05 alpha level. The RM-MANOVA indicated that dynamic velocity and isometric force of both serves and forehand strokes were significantly greater when the subjects grunted (F = 46.572, p < 0.001, power = 1.00). Peak muscle activity in the external oblique and pectoralis major muscles was also greater when grunting during both types of strokes (F = 3.867, p = 0.05, power = 0.950). Grunt history, gender, perceived advantages, and disadvantages of grunting, years of experience, highest level of competition, and order of testing did not significantly alter any of these results. The velocity, force, and peak muscle activity during tennis serves and forehand strokes are significantly enhanced when athletes are allowed to grunt.

Children's learning of tennis skills is facilitated by external focus instructions

The present study examined the effects of instructions promoting external versus internal foci of attention on the learning of a tennis forehand stroke in 11-year old children. Three groups of participants practiced hitting tennis balls at a target. External focus group participants were instructed to direct their attention to the movement of the racquet, while participants in the internal focus group were asked to direct their attention to the movements of their arm. Participants in a control group did not receive attentional focus instructions. Two days after the practice phase (60 trials), learning was assessed in retention and transfer tests. The results showed that the external focus group demonstrated greater accuracy in hitting a target relative to the two other groups in retention, and relative to the internal focus group in transfer. We conclude that instructions inducing an external focus of attention can enhance children's sport skill learning.

IMPACT OF SHIFT IN FOCUS OF ATTENTION ON LEARNING TABLE TENNIS BACKHAND WITH SELF-TALK IN HIGH SCHOOL FEMALES STUDENTS

Aim: The purpose of the present study was to investigate the effect of variability of attentional focus distance by self-talk on the learning of table tennis backhand. Methods: Therefore, 80 high school girls by mean age 16(+-0/62) yr. were randomly selected from sport school of Sanandaj and assigned to 5 groups. After pretest, the participants performed 180 forehand strokes during 6 sessions with repeating the words *slightly rotation* in the internal focus group *slightly open* in the near external focus group, *over the net* in the far external focus group, and each of the words *slightly rotation, slightly open, and over the net* respectively in each 2 sessions in the increasing distance of attentional focus group. Control group performed without self-talk during acquisition phase. Retention test was performed 48 hours after acquisition test in the same situation without self-talk, and after half an hour break, transfer test was done by changing the direction of target (parallel forehand) without self-talk. The accuracy and the pattern of forehand strokes were measured by a 5 point-scale (Liao and Masters, 2001) and researcher-made scale, respectively. At the end of acquisition phase, participants filled out the frequency and self-talk beliefs questionnaire. Results: According to the results of 2-factor mixed ANOVA, acquisition, retention, and transfer of backhand accuracy in internal focus of attention group were significantly lower than other groups (p&lt;0.05). Furthermore, the effect of increasing attentional focus distance on acquisition of backhand pattern was significant. The effect of near external attentional focus on retention of pattern was significant. But transfer of stroke pattern in control group was significantly more than far external focus group (p&lt;0.05). Conclusions: Thus, it is recommended to use self-talk by increasing attentional focus and near external attentional focus and not to use internal focus of attention to instruct backhand to novice adolescents.

A comparison of the upper limb movement kinematics utilized by children playing virtual and real table tennis

Active virtual games (AVG) may facilitate gross motor skill development, depending on their fidelity. This study compared the movement patterns of nineteen 10–12yr old children, while playing table tennis on three AVG consoles (Nintendo Wii, Xbox Kinect, Sony Move) and as a real world task. Wrist and elbow joint angles and hand path distance and speed were captured. Children playing real table tennis had significantly smaller (e.g. Wrist Angle Forehand Real-Kinect: Mean Difference (MD): −18.2°, 95% Confidence Interval (CI): −26.15 to −10.26) and slower (e.g. Average Speed Forehand Real-Kinect: MD: −1.98ms−1, 95% CI: −2.35 to −1.61) movements than when using all three AVGs. Hand path distance was smaller in forehand and backhand strokes (e.g. Kinect-Wii: MD: 0.46m, 95% CI: 0.13–0.79) during playing with Kinect than Move and Wii. The movement patterns when playing real and virtual table tennis were different and this may impede the development of real world gross motor skills. Several elements, including display, input and task characteristics, may have contributed to the differences in movement patterns observed. Understanding the interface components for AVGs may help development of higher fidelity games to potentially enhance the development of gross motor skill and thus participation in PA.

Nonlinear pedagogy: an effective approach to cater for individual differences in learning a sports skill.

Learning a sports skill is a complex process in which practitioners are challenged to cater for individual differences. The main purpose of this study was to explore the effectiveness of a Nonlinear Pedagogy approach for learning a sports skill. Twenty-four 10-year-old females participated in a 4-week intervention involving either a Nonlinear Pedagogy (i.e.,manipulation of task constraints including equipment and rules) or a Linear Pedagogy (i.e., prescriptive, repetitive drills) approach to learn a tennis forehand stroke. Performance accuracy scores, movement criterion scores and kinematic data were measured during pre-intervention, post-intervention and retention tests. While both groups showed improvements in performance accuracy scores over time, the Nonlinear Pedagogy group displayed a greater number of movement clusters at post-test indicating the presence of degeneracy (i.e., many ways to achieve the same outcome). The results suggest that degeneracy is effective for learning a sports skill facilitated by a Nonlinear Pedagogy approach. These findings challenge the common misconception that there must be only one ideal movement solution for a task and thus have implications for coaches and educators when designing instructions for skill acquisition.

Potential effects of racket grip size on lateral epicondilalgy risks

The effects of tennis racket grip size on the forces exerted by muscles affecting lateral epicondylalgia (LE) were assessed in this study. Grip forces and joint moments applied on the wrist were quantified under three different handle size conditions, with and without induced muscle fatigue for intermediate and advanced players. The obtained experimental results were then used as input data of a biomechanical model of the hand. This simulation aimed to quantify the impact of grip strength modulation obtained in the experiment on the wrist extensor muscle forces. Our results show that there is an optimal grip diameter size defined as the handle inducing a reduced grip force during the stroke, in both fatigued and non-fatigued sessions. The results of the simulation suggested that extensor muscles were highly employed during forehand strokes, which confirms that the mechanical overuse of extensor tendons is a potential risk factor for tennis elbow occurrence. The handle grip size appeared to be a significant factor to reduce this extensor tendon loading. This suggests that grip size should be taken into account by players and designers in order to reduce the mechanical risk factors of overuse injury occurrence.

Scapulothoracic kinematics during tennis forehand drive

Scapular dyskinesis is recognized as an abnormality in the kinetic chain; yet, there has been little research quantifying scapular motion during sport tasks. Tennis forehand drives of eight highly skilled tennis players were studied to assess the scapulothoracic kinematics and evaluate repeatability using video-based motion analysis. Scapulothoracic downward/upward rotation, posterior/anterior tilt, and internal/external rotation were computed using an acromial marker cluster. On average, the upward rotation, anterior tilt, and internal rotation varied from 1° to 26°, from 7° to 32°, and from 42° to 100°, respectively, during the tennis forehand drive. During the backswing and forward swing phases of the forehand stroke, small changes were observed for the three scapular angle values, while all angles increased rapidly during the follow-through phase. This suggests that the tennis forehand drive may contribute to scapula dyskinesis, mainly due to the great amplitude in scapulothoracic anterior tilt and internal rotation observed during the follow-through phase. Knowledge of normal scapula motion during sport tasks performed at high velocity could improve the understanding of various sport-specific adaptations and pathologies.

Prediction of human actions: Expertise and task‐related effects on neural activation of the action observation network

The action observation network (AON) is supposed to play a crucial role when athletes anticipate the effect of others' actions in sports such as tennis. We used functional magnetic resonance imaging to explore whether motor expertise leads to a differential activation pattern within the AON during effect anticipation and whether spatial and motor anticipation tasks are associated with a differential activation pattern within the AON depending on participant expertise level. Expert (N=16) and novice (N=16) tennis players observed video clips depicting forehand strokes with the instruction to either indicate the predicted direction of ball flight (spatial anticipation) or to decide on an appropriate response to the observed action (motor anticipation). The experts performed better than novices on both tennis anticipation tasks, with the experts showing stronger neural activation in areas of the AON, namely, the superior parietal lobe, the intraparietal sulcus, the inferior frontal gyrus, and the cerebellum. When novices were contrasted with experts, motor anticipation resulted in stronger activation of the ventral premotor cortex, the supplementary motor area, and the superior parietal lobe than spatial anticipation task did. In experts, the comparison of motor and spatial anticipation revealed no increased activation. We suggest that the stronger activation of areas in the AON during the anticipation of action effects in experts reflects their use of the more fine-tuned motor representations they have acquired and improved during years of training. Furthermore, results suggest that the neural processing of different anticipation tasks depends on the expertise level.

Effects of a Simulated Tennis Match on Lymphocyte Subset Measurements

Tennis is an activity requiring both endurance and anaerobic components, which could have immunosuppressive effects postexercise. Purpose The purpose of this investigation was to determine the effect of a simulated tennis match on apoptotic and migratory markers on lymphocyte subsets. Method Male high school (n = 5) and college (n = 3) tennis players (M age = 18.9 ± 3.3 years) completed 10 sets of a tennis protocol including serves, forehand strokes, and backhand groundstrokes with 1-min rest periods between sets. Apoptosis antigen 1 receptor (CD95) and chemokine receptor fractalkine (CX3CR1) expression was analyzed on helper T lymphocytes (CD4+), cytotoxic T lymphocytes (CD8+), and B lymphocytes (CD19+) twice, at resting baseline and immediately after all 10 sets of the tennis protocol. Results An increase was observed in each lymphocyte subtype (p < .02, effect size = .41), and comparison of absolute changes revealed increases in CD4+/CD95+, CD8+/CD95+, and CD8+/CX3CR1 lymphocytes following the tennis protocol (p < .01, effect size = .43), but not in CD19+ cells. Conclusions A simulated tennis match has adequate intensity to induce immune modulations in terms of increased cell death and cellular migration in T lymphocyte subsets. Lymphocytopenia following tennis play is influenced by both apoptotic and migratory mechanisms.

The effect of haptic guidance and visual feedback on learning a complex tennis task

While haptic guidance can improve ongoing performance of a motor task, several studies have found that it ultimately impairs motor learning. However, some recent studies suggest that the haptic demonstration of optimal timing, rather than movement magnitude, enhances learning in subjects trained with haptic guidance. Timing of an action plays a crucial role in the proper accomplishment of many motor skills, such as hitting a moving object (discrete timing task) or learning a velocity profile (time-critical tracking task). The aim of the present study is to evaluate which feedback conditions-visual or haptic guidance-optimize learning of the discrete and continuous elements of a timing task. The experiment consisted in performing a fast tennis forehand stroke in a virtual environment. A tendon-based parallel robot connected to the end of a racket was used to apply haptic guidance during training. In two different experiments, we evaluated which feedback condition was more adequate for learning: (1) a time-dependent discrete task-learning to start a tennis stroke and (2) a tracking task-learning to follow a velocity profile. The effect that the task difficulty and subject's initial skill level have on the selection of the optimal training condition was further evaluated. Results showed that the training condition that maximizes learning of the discrete time-dependent motor task depends on the subjects' initial skill level. Haptic guidance was especially suitable for less-skilled subjects and in especially difficult discrete tasks, while visual feedback seems to benefit more skilled subjects. Additionally, haptic guidance seemed to promote learning in a time-critical tracking task, while visual feedback tended to deteriorate the performance independently of the task difficulty and subjects' initial skill level. Haptic guidance outperformed visual feedback, although additional studies are needed to further analyze the effect of other types of feedback visualization on motor learning of time-critical tasks.