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This study aimed to understand how tennis coaches perceive and approach the development of grip positions, a foundational skill in tennis. Professionally accredited coaches, classed as less (n = 140) or more (n = 86) experienced, participated in an online survey where they provided their perspectives on the importance of developing grip positions and their opinions on using physically constraining tools for coaching. Irrespective of coach experience level, the findings revealed that technique development and grip position training were ranked as the two most important components in foundational tennis skill development. The Semi-western grip for forehand (less: 68%; more: 65%), a combination of Continental and Eastern grips for double-handed backhand (less: 59%; more: 48.8%), and the Continental grip for serves (both: 94%) were identified as the most commonly taught positions for different shots. Perceived barriers to developing grip positions were out of habit (less: 62%; more: 56%), discomfort (less: 58%; more: 50%), and lack of confidence (less: 44%; more: 21%). Notably, 65% of coaches expressed an openness to incorporating physically constraining tools to enhance grip-specific skill development. Overall, this study serves as a foundational resource, guiding coaches in optimising their strategies for foundational tennis development, prompting further research in this area. [ABSTRACT FROM AUTHOR]

The study aimed to investigate the influence of key technical determinants on shooting performance in both air rifle and pistol shooting disciplines. Following a systematic search across four databases (PubMed, CINAHL, SPORTDiscus, and Cochrane Library), a total of 22 articles were included. The findings indicate that there was a significant correlation between the stability of hold component, as measured by DEV_X (r = −0.60; 95% confidence interval (CI) = −0.69 to −0.49; p < 0.001) and HITf (r = 0.69; 95% CI = 0.56 to 0.79; p < 0.001) and shooting performance in both shooting disciplines. In addition, HITr, another stability component, revealed a significant positive correlation for shooting performance (r = 0.60; 95% CI = 0.35 to 0.77; p < 0.001) in air pistol shooting. Furthermore, in both disciplines, there was a significant positive correlation between shooting performance and measures of aiming accuracy such as COGhit (r = 0.64; 95% CI = 0.49 to 0.75; p < 0.001), Targetf (r = 0.75; 95% CI = 0.63 to 0.84; p < 0.001), and Targetr (r = 0.60; 95% CI = 0.33 to 0.78; p < 0.001). In both disciplines, there was a strong negative correlation between the cleanliness of triggering and shooting performance (r = −0.63; 95% CI = −0.75 to −0.48; p < 0.001). Time on target measure significantly correlated with shooting performance (r = 0.52; 95% CI = 0.31 to 0.68; p < 0.001) across both disciplines. The relationship between postural balance and shooting performance in air rifle shooting was negative, indicating that better postural balance is associated with improved shooting (r = −0.53; 95% CI = −0.69 to −0.33; p < 0.001). This review emphasizes the significance of various technical components in both air rifle and pistol disciplines. [ABSTRACT FROM AUTHOR]

Acquisition evaluations are expensive, have a high time liability, and tend to prioritize engineering requirements over human factors and good experimental design. Shooting serials usually consist of static prone shooting to minimize movement variability, increase reliability of accuracy and timing data or use a single data point to make acquisition decisions. To better understand the number of trials required to achieve representative performance of accuracy and timing, 60 shots from the standing unsupported position while cyclically moving the weapon from the low ready to shoot was utilized. Intra‐class correlations, standard error of measurement, minimal detectable change, and sequential averaging analysis (SAA) were used to evaluate the variables of radial error, shot interval, x‐bias and y‐bias over the 60 shots. The number of trials required to achieve an intraclass correlation of greater than 0.8 ranged from 2 (shot interval) to 58 (y‐bias), whereas SAA varied between 3 (x‐bias) and 43 (shot interval) trials. When averaging 10 shots at a time, the moving intraclass correlation remained above 0.8 for radial error and y‐bias between 7 and 15 shots, shot interval from the second shot, but x‐bias never reached 0.8. The number of trials required to satisfy each reliability method was inconsistent, in line with previous literature. Given the limitations identified in the literature as well as practical considerations such as the preference for prioritizing radial error reasonable performance stability can be achieved after 15 shots, and using the moving intraclass correlation results it is recommended that the first six shots are discarded with the following nine shots used for analysis. [ABSTRACT FROM AUTHOR]

Gait stability in soldiers can be affected by task constraints that may lead to injuries. This study determined the effects of weapon handling and speed on gait stability in seventeen soldiers walking on a treadmill with and without a replica weapon at self-selected (SS), 3.5 km·h−1, 5.5 km·h−1, and 6.5 km·h−1 while carrying a 23-kg load. Local dynamic stability was measured using accelerometry at the sacrum (LDESAC) and sternum (LDESTR). No significant weapon and speed interaction were found. A significant effect of speed for the LDESAC, and a significant effect of speed and weapon for the LDESTR were found. Per plane analyses showed that the weapon effect was consistent across all directions for the LDESTR but not for LDESAC. Weapon handling increased trunk but did not affect pelvis stability. Speed decreased stability when walking slower than SS and increased when faster. These findings can inform injury prevention strategies in the military. Practitioner summary: We determined the effects of two constraints in soldier's walking stability, weapon handling and speed, measured at the trunk and sacrum. No constraints interactions were found, however, lower stability when walking slow and greater stability with the weapon at the trunk can inform preventive strategies in military training. [ABSTRACT FROM AUTHOR]

There is limited research on the on-field performance of previously concussed athletes. The aim of this exploratory study was to investigate athlete technical performance pre- and post-concussion in Australian Football. Using publicly available data, male athletes who sustained a concussion during the 2016–19 professional Australian Football League seasons were analysed across five games pre- and post-concussion (concussion events n = 41, age 25.4 ± 3.5 years; control n = 39, age 25.2 ± 3.6 years). Mean technical performance metrics (goals, time-on-ground percentage, kicks, ground ball and disposal efficiency, contested marks) over the five games pre- and post-concussion, as well as within-athlete performance variability measures (standard deviation and coefficient of variation) were analysed. Results showed no significant group-by-time interactions, nor effect of time (pre-post) for any technical performance metric. Similarly, the within-athlete standard deviation and coefficient of variation of technical performance metrics showed no group-by-time interaction, nor effect for time. This retrospective study has shown that athlete performance averaged over five games is not affected post-concussion in elite men's Australian Football. Further prospective studies controlling for contextual match factors based on opposition and environmental conditions may be required to identify potential in-game technical performance changes following return-to-play from concussion. [ABSTRACT FROM AUTHOR]

The aim of this study was to understand the association between impact and movement characteristics during whole game and peak 1- to 10-minute rolling windows in professional rugby union. Maximal impact (impacts·min-1) and corresponding running (m·min-1) characteristics as well as maximal running (m·min-1) and corresponding impact (impacts·min-1) characteristics were obtained for 160 athletes from 4 teams across the 2018 and 2019 Super Rugby seasons. A linear mixed-effects model reported a positive association between whole-game running and impacts, where greater impact characteristics corresponded with greater running characteristics. The average 1-minute peak running characteristics (150-160 m·min-1) typically occurred when no impacts occurred. The average 1-minute peak impact characteristics (4-6 impacts·min-1) corresponded with an average relative distance of 90-100 m·min-1. Worst case scenario observed impact characteristics as large as 15 impacts·min-1 with a corresponding relative distance of 140 m·min-1. When training for peak period characteristics, running may be completed in isolation; however, peak impacts often occur in conjunction with moderate to high running movements. Given running and impact characteristics can appear concurrently within game play, this highlights the need to train them accordingly. As such, when prescribing training drills to replicate the peak characteristics in rugby union, consideration should be taken for both running and impact characteristics. [ABSTRACT FROM AUTHOR]

The purpose of this study was to compare the peak periods (1- to 6-minute epochs) for three different training methods (game-based training – GBT; small-sided games – SSG; and conditioning training – CT) in elite male rugby union (RU) players. The peak movement (m·min−1) and impact (impact·min−1) characteristics of 42 players during in-season training were assessed. When comparing between training methods, SSG drills produced the greatest peak movement characteristics for all time epochs (1-minute average peak periods – SSG 195 m·min−1, GBT 160 m·min−1, and CT 144 m·min−1). The peak impact characteristics performed during training were 1–2 impact·min−1 for a 1-minute period and then decreased as the time period increased for all training methods. The greatest distribution of training time occurred at 30–39% (SSG and CT) and 40–49% (GBT) of peak movement intensity, with less than 5% of training performed at or above 80% peak intensity across all drill types. Findings from the current study show that the peak movement periods (m·min−1) in RU training from all three training methods match or exceed those which are previously reported in peak gameplay, yet their ability to replicate peak impact characteristics is questionable. [ABSTRACT FROM AUTHOR]

The purpose of this study was to compare double-handed backhand kinematics of the non-dominant wrist of tennis players using either an eastern or continental grip position with the non-dominant hand. Trajectory data were captured using sixty reflective markers on sixteen sub-elite right-handed tennis players using a 12-camera VICON motion capture system (250 Hz). Participants executed double-handed backhands using two non-dominant grip positions (Eastern [E] and Continental [C]), aiming for two crosscourt zones (Deep [D] and Short [S]), totalling to four conditions (ED, CD, ES and CS). Three successful attempts from each condition were selected for analysis. The eastern grip demonstrated faster horizontal racket head velocity compared to the continental grip. However, no differences were observed in accuracy or spin rate between grips (p > 0.05). In the non-dominant upper limb, elbow flexion was smaller in the continental condition throughout the swing, whilst wrist extension and ulnar deviation was larger. Collectively, these data suggest that the continental grip may place the wrist in a position vulnerable to overuse injury. Future research into the kinetics of the double-handed backhand would help better understand the onset of ulnar-side wrist pain in tennis. [ABSTRACT FROM AUTHOR]

Athletes alter ball flight trajectory in interceptive ball sports to change task constraints that their opponents must overcome to successfully meet the ball in flight. This systematic review identified how athletes change their techniques to alter the ball flight trajectory in high-performance interceptive sports where the ball is projected by the hand towards an opponent. Studies that reported the kinematics or ball flight characteristics of these movements were searched for using SportsDiscus, Scopus, MEDLINE and CINAHL Plus databases up to 27 April 2021. Forty-eight articles met the inclusion criteria, including 19 baseball, 12 cricket, five handball, four softball, three volleyball and five water polo studies. Extracted data were presented as ranges and descriptively analysed to report athlete sporting actions. Trajectory deviation can be caused by imparting an altered seam orientation or spin rate and axis of rotation on the ball. Athletes impart sidespin or manipulate seam orientation to cause lateral deviation while topspin and backspin are used to create vertical changes in the flight path. Adjusting the shoulder, forearm, wrist, hand and fingers of the throwing or striking arm can be used to impart an altered seam orientation or spin rate and axis of rotation on the ball. The findings of this review could assist coaches and athletes across a variety of sports to improve the ability to deviate the ball during flight. [ABSTRACT FROM AUTHOR]

Tredrea, MSJ, Middleton, KJ, Bourne, MN, Carey, DL, Scanlan, AT, and Dascombe, BJ. Load centralization does not affect the kinetic and kinematic output of countermovement jumps. J Strength Cond Res 36(4): 1084-1089, 2022-This study aimed to compare the kinetics, kinematics, and performance of countermovement jumps (CMJs) when completed with 2 different loading conditions (centralized or peripheral) across increasing loads. Seventeen subjects (12 men and 5 women) randomly completed 2 series of CMJs with increasing loads separated by a 30-minute rest period between conditions. Subjects were loaded with either a weighted vest (centralized) or straight barbell (peripheral). A randomized, counterbalanced crossover design was used with incremental loads of 10, 20, 30, 40, and 50% of body mass added to the vest or barbell. Measures of peak force, acceleration, velocity, and power were calculated across each subphase of the CMJs. No significant differences were observed in kinetic or kinematic variables between loading conditions. Within each condition there were significant reductions (p < 0.05) in peak concentric velocity and acceleration, as well as significant increases (p < 0.05) in peak force when the external load increased. Furthermore, braking and propulsive phase duration significantly increased (p < 0.05) and jump height significantly decreased (p < 0.05) as the external load increased. Countermovement jump performance was similar in both central and peripheral loading, whereas increasing load significantly affected jump height, force, velocity, and acceleration variables irrespective of load position. The training stimulus from an external load placed centrally or peripherally is similar regardless of where it is positioned; however, from a practical perspective, a weighted vest may provide a more mobile and safer alternative than a barbell. [ABSTRACT FROM AUTHOR]

Wearable microtechnology is effective in detecting fast deliveries in cricket, however methods to quantify delivery intensity have not been established. This study aimed to investigate the utility of wearable sensors in quantifying cricket fast bowling intensity. Fifteen sub-elite male fast bowlers performed deliveries at warm-up, match, and maximal intensities. A principal component analysis resulted in the selection of perceived exertion and seven variables of bowling exertion derived from trunk- (PlayerLoad™, trunk flexion velocity, trunk forward rotation velocity) and tibia-mounted (tibial acceleration at back foot contact, front foot contact, back foot re-contact and front foot re-contact) inertial measurement units for further analysis. Repeated measures ANOVAs were used to investigate the effect of intensity on outcome variables. Significant main effects of intensity and large effect sizes were identified for all variables (p <.05, np2 > 0.14). Measures from the match and maximal conditions were significantly larger compared with the warm-up condition (Pholm <.05). No differences were observed between the match and maximal conditions (p >.05). Inertial measurement metrics can distinguish between a warm-up effort and both match and maximal fast bowling delivery intensity. These devices provide a unique, time-efficient approach to cricket fast bowling exertion quantification. [ABSTRACT FROM AUTHOR]

This study quantifies the maximum number of impacts and peak running demands during 1– to 10– minute rolling window periods in elite rugby union matches using a multi-team dataset (n = 2232 player-games). Maximum values for impacts (impacts·min−1) and running (m·min−1) were calculated for 161 athletes from four teams across the 2018 and 2019 Super Rugby seasons. The effect of window duration and playing position on peak impact and running demands were estimated using linear mixed effect models and prediction intervals. The peak impact and running demands for a 1-min period were 4.5 – 5.5 impacts·min−1 and 150 – 180 m·min−1, depending on playing position. While small variations in mean impact and running movements could be observed by position, the large prediction interval and individual player variation meant that there was no practically meaningful difference by position. As such, when prescribing training drills to replicate the peak demands in rugby union, impact and running movements of players can be similar, regardless of position. Using a prediction interval allows us to identify the range where the demands in a future game may fall, and are beneficial to use when also trying to prepare players for the demands of rugby union. [ABSTRACT FROM AUTHOR]

This study investigated the effects of weapon handling on the physiological responses and walking-gait kinematics during load carriage. Seventeen soldiers completed four twelve-minute bouts of treadmill walking at incremental speeds (3.5, 5.5, 6.5 km . h -1 and self-selected) carrying 23.2-kg of additional load, while either handling a weapon or not handling a weapon. Physiological, perceptual and biomechanical outcomes were measured throughout each trial. A weapon-by-speed interaction ( p < .05) was observed for hip flexion-extension during loading response and mid-swing. Weapon handling elevated ( p < .05) cardiorespiratory responses at 6.5 km . h -1 . Main effects ( p < .05) of weapon handling were observed for ventilation, oxygen pulse, effort perception, stride length and knee flexion-extension during toe-off. No main effects of weapon handling were observed for any other biomechanical measures. These findings demonstrate that physiological and biomechanical responses to weapon handling are likely walking-speed dependent. Practitioner summary : Weapon handling is an important part of many load-carriage tasks but is rarely investigated. Physiological and biomechanical responses were assessed at incremental speeds during load carriage. Despite similar biomechanics, there was greater physiological demands at faster walking speeds, suggesting an increased contribution from isometric muscle contractions for weapon stabilisation.