Bowler and coach experiential knowledge of new ball swing bowling in elite cricket.

Swing bowling can influence the outcome of cricket matches, but technique characteristics and coaching practices have not been investigated at an elite level. This study aimed to provide insight into the perceived technique parameters, coaching practices and variables contributing to conventional new ball swing bowling in elite cricket. Six Australian Test match fast bowlers and six Australian international and national-level coaches were interviewed. A reflexive thematic analysis of interview transcripts generated themes associated with swing bowling. Most bowlers reported their technique allows them to naturally create either inswing or outswing, with technique variations used to create swing in the opposite direction. To increase delivery effectiveness, bowlers and coaches recommended pitching the ball closer to the batter in length and varying release positions along the crease. Coaches recommended making individualised technique adjustments, but suggested all bowlers could benefit from maintaining balance and forward momentum to create a consistent release position in repeated deliveries. This study could inform training strategies to alter techniques and improve swing bowling performance. Future research should investigate the physical qualities of fast bowlers and use biomechanical analyses to provide a deeper understanding of swing bowling.

Inter- and intra-athlete technique variability of conventional new ball swing bowling in elite and pre-elite Australian male fast bowlers.

This study aimed to investigate inter- and intra-athlete technique variability in pre-elite and elite Australian fast bowlers delivering new ball conventional swing bowling. Ball grip angle and pelvis, torso, shoulder, elbow, wrist, upper arm, forearm, and hand kinematics were investigated at the point of ball release for inswing and outswing deliveries. Descriptive evaluations of group and individual data and k-means cluster analyses were used to assess inter- and intra-bowler technique variability. Inter-athlete technique and ball grip variability were identified, demonstrating that skilled bowlers use individualised strategies to generate swing. Functional movement variability was demonstrated by intra-athlete variability in successful swing bowling trials. Bowlers demonstrated stable technique parameters in large proximal body segments of the pelvis and torso, providing a level of repeatability to their bowling action. Greater variation was observed in bowling arm kinematics, allowing athletes to manipulate the finger and ball position to achieve the desired seam orientation at the point of ball release. This study demonstrates that skilled bowlers use individualised techniques and grips to generate swing and employ technique variations in successive deliveries. Coaches should employ individualised training strategies and use constraints-led approaches in training environments to encourage bowlers to seek adaptive movement solutions to generate swing.

Surveillance is the first step to preventing injury among fast jet aircrew: results of a 2-year prospective cohort study.

OBJECTIVES: Injury surveillance is imperative for injury prevention but difficult in military populations. Our objective was to accurately describe the pattern of musculoskeletal complaints among Royal Australian Air Force (RAAF) fast jet aircrew (FJA) using the validated University of Canberra Fast Jet Aircrew Musculoskeletal Questionnaire (UC-FJAMQ) over a 2-year period, and determine injury burden on the workforce and operational capability. METHODS: 306 RAAF FJA were monitored over a 2-year period (4×5 month reporting periods). Musculoskeletal complaint episodes (MCEs) were captured weekly using the UC-FJAMQ. Time loss episodes (TLEs) were captured from the UC-FJAMQ and injury registers completed by embedded physiotherapists. Cumulative severity and operational impact scores from the UC-FJAMQ, and time loss duration, were used to describe severity and calculate burden. RESULTS: Mean weekly UC-FJAMQ response rate was 62%. 1012 MCEs were captured, with a mean weekly prevalence of 14.9% (95% CI 14.2-15.6), and incidence of 4.1 episodes per person-year (95% CI 3.9-4.4). A total of 145 TLEs were captured, with a mean 5-month prevalence of 12.4% (range 8.9-15.3%), and incidence of 0.37 episodes per person-year (95% CI 0.31-0.43). Spinal regions accounted for 81% of MCEs and contributed 76% and 85% of burden in relation to cumulative severity and operational impact, respectively. 57% of TLE burden came from spinal regions. CONCLUSIONS: Despite modest weekly UC-FJAMQ response rates, musculoskeletal complaints were shown to be widespread and negatively impact operational capability. Future injury prevention efforts among FJA should focus on spinal regions, particularly the neck.

Previous experiences can influence individual cricket spin bowlers' perceptions of affordances in the performance landscape.

The ecological dynamics framework emphasises that movement solutions are guided by the relationship that exists between the performer and their environment, scaled to an individual's own action capabilities. This suggests that representative practice tasks should be used in high performance settings to encourage individually optimised movement solutions for both team and individual sports. This study specifically focuses on individual cricket spin bowlers and aims to understand the influence of their prior learning experiences on their perceptual attunement strategies when tasked with performing on a familiar Australian cricket pitch and a less familiar bespoke international (Indian) pitch. Two right hand leg spin bowlers that were part of a group of eight emerging expert spin bowlers were chosen for individual analysis. Bowler A reported 80 prior experiences of bowling on subcontinental (i.e., India, Pakistan, or Bangladesh) pitches whereas Bowler B had only 20 prior experiences. Overall, both bowlers' outcome performances either met or exceeded their expectations. Bowler A chose to calibrate his bowling style on the less familiar pitch to improve the fit between his delivery characteristics and the environmental pitch conditions, whereas Bowler B maintained his bowling style, even though he recognised a difference in the pitch conditions. Therefore, Bowler A maintained stable performance outcomes by implementing flexible movement solutions. In contrast, while Bowler B achieved his expected performance outcomes, his lack of diverse learning experiences may limit his action capabilities, although more performance trials are needed to confirm this conclusion. Regardless, this study demonstrates that there is valuable information in knowing how a player achieves a successful result, which should be coupled with performance outcomes to help create individualised development strategies.

Hamstring musculotendon mechanics of prospectively injured elite rugby athletes.

The musculotendon mechanics of the hamstrings during high-speed running are thought to relate to injury but have rarely been examined in the context of prospectively occurring injury. This prospective study describes the hamstring musculotendon mechanics of two elite rugby players who sustained hamstring injuries during on-field running. Athletes undertook biomechanical analyses of high-speed running during a Super Rugby pre-season, prior to sustaining hamstring injuries during the subsequent competition season. The biceps femoris long head muscle experienced the greatest strain of all hamstring muscles during the late swing phase. When expressed relative to force capacity, biceps femoris long head also experienced the greatest musculotendon forces of all hamstring muscles. Musculotendon strain and force may both be key mechanisms for hamstring injury during the late swing phase of running.

"Train how you play": Using representative learning design to train amateur cricketers.

Training task design with amateur female cricketers has typically comprised of deconstructed and monotonous approaches which may not maximise skill development. Clear guidelines to improve these practices in this cohort are lacking. The training environment should provide the same sources of information, decisions and variability as matches in order to prepare players for the match environment, which can be achieved through representative learning design (RLD). An RLD training intervention designed to promote skill development was performed over five weeks with two amateur female cricket teams to provide a framework for community coaches at the foundation stage of cricket. Skill development was recorded as changes in skilled actions for batting and bowling, with cognitions coded as themes for each skill during training. Six of ten batters and seven of eight bowlers exhibited increases in skill development ranging between 7-49%. Changes in batting and bowling behaviour improved substantially between moderately and extensively designed sessions. Batters' thoughts shifted from their own skill execution to objectives, while bowlers focused on their opponent's execution. Moderate to extensive RLD appears to promote skill development in amateur cricketers, making it a viable option for coach education and training design at the foundation level of cricket.

Effect of Footwear on the Biomechanics of Loaded Back Squats to Volitional Exhaustion in Skilled Lifters.

ABSTRACT: Brice, SM, Doma, K, and Spratford, W. Effect of footwear on the biomechanics of loaded back squats to volitional exhaustion in skilled lifters. J Strength Cond Res 36(10): 2676-2684, 2022-This study examined whether footwear influences the movement dynamics of barbell back squats to volitional exhaustion in experienced lifters. Eleven men (1 repetition maximum [1RM] = 138 ± 19 kg; 1RM % body mass = 168 ± 18%) performed 3 sets (5-12 ± 4 repetitions per set) of loaded barbell back squats to volitional exhaustion using raised-heel and flat-heel footwear. Barbell motion as well as moments, angles, angular velocity, and power in the sagittal plane at the ankle, knee, hip, and lumbopelvis were examined during the second repetition of the first set (T second ) and the final repetition of the third set (T final ). There were significant reductions ( p < 0.05) in lower-limb concentric angular velocity and power output for both footwear conditions. For the raised-heel condition at T final , hip and knee concentric angular velocities were significantly slower ( p < 0.05), and knee concentric power output was significantly less ( p < 0.05) compared with the flat-heel condition. A reduction in barbell velocity was not observed for the raised-heel condition despite there being reduction in hip and knee angular velocities. Furthermore, no differences were identified in lower-limb joint moments or any of the biomechanical characteristics of the lumbopelvis between the footwear conditions. The findings of this study suggest that neither type of footwear reduced joint loading or improved joint range-of-motion.

Factors associated with neck pain in fighter aircrew: a systematic review and meta-analysis.

Neck pain is a common complaint among fighter aircrew, impacting workforce health and operational capability. This systematic review aimed to identify, evaluate and synthesise the current evidence for factors associated with the occurrence of neck pain among fighter aircrew. Six electronic databases were searched in June 2019 and updated in June 2020 utilising the maximum date ranges. Included studies were appraised for methodological quality, ranked according to level of evidence and relevant data extracted. Where methods were homogeneous and data availability allowed, meta-analyses were performed. A total of 20 studies (16 cross sectional, one case-control, one retrospective cohort and two prospective cohort) were eligible for inclusion. Of the 44 factors investigated, consistent evidence was reported for greater occurrence of neck pain among aircrew operating more advanced aircraft and those exposed to more desk/computer work, while another 12 factors reported consistent evidence for no association. Of the 20 factors where meta-analyses could be performed, greater occurrence of neck pain was indicated for aircrew: flying more advanced aircraft, undertaking warm-up stretching and not placing their head against the seat under greater +Gz. Despite many studies investigating factors associated with neck pain among fighter aircrew, methodological limitations limited the ability to identify those factors that are most important to future preventive programmes. High-quality prospective studies with consistent use of definitions are required before we can implement efficient and effective programmes to reduce the prevalence and impact of neck pain in fighter aircrew. PROSPERO registration number: CRD42019128952.Neck pain is a common complaint among fighter aircrew, impacting workforce health and operational capability. This systematic review aimed to identify, evaluate and synthesise the current evidence for factors associated with the occurrence of neck pain among fighter aircrew.

Shorter work boot shaft height improves ankle range of motion and decreases the oxygen cost of work.

Work boots featuring design elements implemented to protect the foot and lower limb are common in many industries. However, boot design can have negative unintended consequences such as increases in work related fatigue and injury risk. This study compared joint kinematics and the physiological cost of two commercially available steel-toed work boots with different shaft designs worn throughout a simulated work task. A boot with a lower-cut and scalloped shaft allowed greater sagittal plane range of motion at the ankle joint compared to a boot with a higher-cut straight shaft, particularly in the late stance phase of the gait cycle. This was coupled with a decreased physiological cost of treadmill walking (2.6 and 3.1% improvement in oxygen consumption and walking economy, respectively), likely caused by a more efficient gait pattern. A lower-cut and scalloped shaft could lead to decreases in work-related fatigue and the subsequent risk of injuries in workers. Practitioner summary: Gait kinematics and the physiological cost of work boots with different shaft heights has not previously been investigated. A randomised cross-over study design found that a boot with a lower shaft height and scalloped collar improved ankle range of motion and reduced the physiological cost experienced by the wearers. Abbreviations: ROM: range of motion; FS: full shaft; SS: scalloped shaft; COM: centre of mass; HR: heart rate; RPE: rating of perceived exertion; ES: effect size.

Bowling action and ball flight kinematics of conventional swing bowling in pathway and high-performance bowlers.

When executed correctly, swing bowling has the potential to influence the outcome of a cricket match, yet little is known about the required bowling action and ball flight characteristics. This study aimed to describe the bowling action and initial ball flight characteristics as well as to identify variables that may be associated with increased swing in pathway and high-performance medium and fast pace bowlers. A 17-camera Vicon motion analysis system captured retro-reflective markers placed on the upper-body of participants and new cricket balls to quantify bowling action and initial ball flight kinematics. Bowlers delivered the ball with their forearm and hand angled in the direction of intended swing with an extended wrist flexing through the point of ball release. Bowlers who produced more swing had increased seam stability, possibly linked to a lower wrist and ball angular velocity. It is believed that swing increases with seam stability, however, optimal ranges may exist for seam azimuth angle, ball angular velocity and release speed. These findings may assist coaches to optimise the performance of bowlers, however, future research should use bowlers who play at higher levels to investigate swing bowling at greater speeds.

Effects of digital filtering on peak acceleration and force measurements for artistic gymnastics skills.

Low-pass filters are ideal when filtering human movements, however the effectiveness of such filters relies on the correct selection of the cut-off frequency. The aim of this study was to determine the most appropriate filter cut-off for acceleration- and force-time data when measuring peak resultant acceleration (PRA) and ground reaction force (PRGRF) during gymnastics landings. Sixteen gymnasts executed backward handsprings and backward somersault landings onto a matted force plate while wearing four inertial measurement units (IMUs). Acceleration- and force-time data were filtered using a fourth-order Butterworth filter at different cut-off frequencies ranging from raw through to 250 Hz. Residual analysis plots were produced, and the PRGRF and PRA for all IMUs were calculated for each participant and skill at all cut-off frequencies. Descriptive statistics, model II linear regressions and Bland-Altman plots were conducted. Results indicated that a minimum 85 Hz cut-off is optimal. High cut-off frequencies (>80 Hz) showed good linear relationships and had minimal mean bias compared with raw values, indicating that either filtered (above ~85 Hz) or raw signals can be used. It is suggested that for applied sports settings no filtering is needed, however a minimum cut-off of 85 Hz should be implemented for research purposes.

Impact of performing heavy-loaded barbell back squats to volitional failure on lower limb and lumbo-pelvis mechanics in skilled lifters.

A common practice in resistance training is to perform sets of exercises at, or close to failure, which can alter movement dynamics. This study examined ankle, knee, hip, and lumbo-pelvis dynamics during the barbell back squat under a moderate-heavy load (80% of 1 repetition maximum (1RM)) when performed to failure. Eleven resistance trained males performed three sets to volitional failure. Sagittal plane movement dynamics at the ankle, knee, hip, and lumbo-pelvis were examined; specifically, joint moments, joint angles, joint angular velocity, and joint power. The second repetition of the first set and the final repetition of the third set were compared. Results showed that while the joint movements slowed (p < 0.05), the joint ranges of motion were not altered There were significant changes in most mean joint moments (p < 0.05), indicating altered joint loading. The knee moment decreased while the hip and lumbo-pelvis moments underwent compensatory increases. At the knee and hip, there were significant decreases (p < 0.05) in concentric power output (p < 0.05). Whilst performing multiple sets to failure altered some joint kinetics, the comparable findings in joint range ofmotion suggest that technique was not altered. Therefore, skilled individuals appear to maintain technique when performing to failure.

The influence of upper-body mechanics, anthropometry and isokinetic strength on performance in wrist-spin cricket bowling.

Delivering a cricket ball with a wrist-spin (WS) bowling technique is considered one of the game's most difficult skills. Limited biomechanical information exists for WS bowlers across skill levels. The purpose of this study was to compare biomechanical, isokinetic strength and anthropometric measures between elite (12) and pathway bowlers (eight). Data were collected using a motion analysis system, dynamometer and a level-two anthropometrist. A regression analysis identified that performance was best explained by increased wrist radial deviation torque and longitudinal axis rotational moments at the shoulder and wrist. From back foot impact (BFI) to ball release (BR), elite bowlers rotated their trunks less, experienced less trunk deceleration resulting in a more front-on position and increased pelvis rotation angular velocity. They also displayed an increased shoulder internal rotation moment as the upper arm moved from external into internal rotation and was a major contributor in the subsequent differences observed in the distal segments of the bowling limb. Anthropometric differences were observed at the wrist and finger joints and may be used to form the basis for talent identification programmes. This study highlights the important contribution to bowling performance of the musculature responsible for producing long axis rotations of the bowling limb.

From the field of play to the laboratory: Recreating the demands of competition with augmented reality simulated sport.

Biomechanical analysis has typically been confined to a laboratory setting. While attempts have been made to take laboratory testing into the field, this study was designed to assess whether augmented reality (AR) could be used to bring the field into the laboratory. This study aimed to measure knee load in volleyball players through a jump task incorporating AR while maintaining the perception-action couplings by replicating the visual features of a volleyball court. Twelve male volleyball athletes completed four tasks: drop landing, hop jump, spike jump, and spike jump while wearing AR smart glasses. Biomechanical variables included patellar tendon force, knee moment and kinematics of the ankle, knee, hip, pelvis and thorax. The drop landing showed differences in patellar tendon force and knee moment when compared to the other conditions. The hop jump did not present differences in kinetics when compared to the spike conditions, instead of displaying the greatest kinematic differences. As a measure of patellar tendon loading the AR condition showed a close approximation to the spike jump, with no differences present when comparing landing forces and mechanics. Thus, AR may be used in a clinical assessment to better replicate information from the competitive environment.

Late swing or early stance? A narrative review of hamstring injury mechanisms during high-speed running.

Hamstring injuries are highly prevalent in many running-based sports, and predominantly affect the long head of biceps femoris. Re-injury rates are also high and together lead to considerable time lost from sport. However, the mechanisms for hamstring injury during high-speed running are still not fully understood. Therefore, the aim of this review was to summarize the current literature describing hamstring musculotendon mechanics and electromyography activity during high-speed running, and how they may relate to injury risk. The large eccentric contraction, characterized by peak musculotendon strain and negative work during late swing phase is widely suggested to be potentially injurious. However, it is also argued that high hamstring loads resulting from large joint torques and ground reaction forces during early stance may cause injury. While direct evidence is still lacking, the majority of the literature suggests that the most likely timing of injury is the late swing phase. Future research should aim to prospectively examine the relationship between hamstring musculotendon dynamics and hamstring injury.

Injury epidemiology and risk factors in competitive artistic gymnasts: a systematic review.

BACKGROUND: Artistic gymnastics is reported to have some of the highest injury rates in sports, which limits participation and often involves considerable medical expenses. PURPOSE: To critically appraise the epidemiological literature on injury patterns and risk factors in competitive artistic gymnastics. STUDY DESIGN: Systematic review. METHODS: Six databases were searched for articles that investigated injuries in competitive artistic gymnasts. Injury incidence, prevalence and risk factor data were extracted, alongside information on injury location, type, severity, nature and mechanism of injury. Quality and level of evidence were assessed using a modified Downs and Black quality index checklist and the Oxford Centre for Evidence-based Medicine guidelines. RESULTS: The search identified 894 articles, with 22 eligible for inclusion. Descriptive analysis showed that injury incidence and prevalence varied from 0.3 to 3.6 injuries per gymnast (female=0.3-3.6, male=0.7) and 2.0-2.3 (female=2.0-2.3, male=2.0), respectively. Male gymnasts sustained mostly upper limb injuries, while female gymnast reported lower limb injuries. Floor was associated with the greatest number of injuries for both male and female gymnasts. Higher competitive level and exposure to competition were risk factors for gymnastics injury: age, body mass, body size, training duration and life stress were significant associated factors. CONCLUSION: Injury incidence and prevalence results are substantial among artistic gymnasts of all competitive levels. Gymnasts who train at highly competitive levels and are exposed to competition environments are a greater risk of injury. Future researchers should implement consistent reporting methods.

Illegal bowling actions contribute to performance in cricket finger-spin bowlers.

With advances in technology, scientists are now able to more accurately measure elbow displacement changes during the cricket bowling action. This has led to the realization that the majority of bowlers undergo some degree of elbow extension during the forward swing phase of bowling. Consequently, the International Cricket Council were obliged to revise the once zero tolerance for elbow extension threshold to a 15° range. However, it is still not understood if bowling with >15° of elbow extension aids performance or alters other kinematic movements. The purpose of this study was to compare performance and technique measures between legal and illegal finger-spin bowlers. Data were collected from 48 pathway and elite bowlers using a 22-camera motion analysis system. Results indicated that the ball velocity and revolutions at ball release of pathway bowlers with illegal actions showed no significant difference and were similar to elite legal bowlers. Technique differences were also identified, with illegal bowlers being more front-on, forcing a reliance on increased elbow flexion and supination to impart effective ball kinematics at ball release. The performance benefit of greater ball velocity and revolutions is obtained when finger-spin bowlers deliver the ball with more than the allowable 15° of elbow extension, thus reinforcing the validity of the current bowling laws. To counteract bowling with an illegal action, it is recommended that a more side-on technique at back foot impact and rotating the trunk through to the point of ball release will assist bowlers in reducing undesirable elbow extension levels.

Does performance level affect initial ball flight kinematics in finger and wrist-spin cricket bowlers?

Spin bowling plays a fundamental role within the game of cricket yet little is known about the initial ball kinematics in elite and pathway spin bowlers or their relationship to performance. Therefore, the purpose of this study was to record three-dimensional ball kinematics in a large and truly high level cohort of elite and pathway finger-spin (FS) and wrist-spin (WS) bowlers, identifying potential performance measures that can be subsequently used in future research. A 22-camera Vicon motion analysis system captured retro-reflective markers placed on the seam (static) and ball (dynamic) to quantify ball kinematics in 36 FS (12 elite and 24 pathway) and 20 WS (eight elite and 12 pathway) bowlers. Results indicated that FS bowlers delivered the ball with an increased axis of rotation elevation, while wrist-spin bowlers placed greater amounts of revolutions on the ball. It also highlighted that ball release (BR) velocity, revolutions and velocity/revolution index scores for both groups and seam stability for FS bowlers, and seam azimuth angle and spin axis elevation angle for WS bowlers, were discriminators of playing level. As such these variables could be used as indicators of performance (i.e. performance measures) in future research.

Contribution of uncertainty in estimation of active drag using assisted towing method in front crawl swimming.

Active drag force in swimming can be calculated from a function of five different variables: swim velocity, tow velocity, belt force, power output and exponent of velocity. The accuracy of the drag force value is dependent on the accuracy of each variable, and on the contribution of each variable to drag estimation. To calculate uncertainty in drag value, first the derivatives of the active drag equation with respect to each variable were obtained. Second, these were multiplied by the uncertainty of that variable. Twelve national age and open level swimmers were recruited to complete four free swimming and five active drag trials. The uncertainties for the free and the tow swim velocities, and for the belt force, contributed approximately 5-6% and 2-3% error, respectively, in calculation of drag. The result of the uncertainty of the velocity exponent (1.8-2.6) indicated a contribution of about 6% error in active drag. The contribution of unequal power output showed that if a power changed 7.5% between conditions, it would lead to about 30% error in calculated drag. Consequently, if a swimmer did not maintain constant power output between conditions, there would be substantial errors in the calculation of active drag.

Peak outward acceleration and ball release in cricket.

The purpose of this study was to investigate the utility of peak outward acceleration (POA) measured from an inertial sensor worn at the wrist as an indicator of the critical end point of the bowling action ­ ball release, a critical element when assessing illegal actions. Twenty-one finger-spin and fast bowlers from nine countries were recruited from the ICC under-19 Cricket World Cup to take part in this research. Bowlers delivered a cross section of their standard deliveries while wearing an inertial sensor placed on their wrists. Ball release was determined by a validated motional analysis ball release (MABR) protocol and compared to the simultaneously collected POA. POA was shown to be highly correlated with MABR (R(2) = 0.98) and a Bland-Altman plot indicated that all 148 trials were within the 3.42 frame (0.014 s) limits of agreement. POA when measured by an inertial sensor worn on the wrist during bowling had a close relationship with an established method of identifying ball release in a biomechanical laboratory regardless of bowler and delivery type. Further, accuracy can be achieved with the adoption of a simple regression equation applied to the POA and as such is a valid measure of ball release in cricket bowlers.