An external focus promotes motor learning of an aiming task in individuals with hearing impairments.

Research has shown that external relative to internal focus (IF) instructions may improve motor performance as well as cognitive function (e.g., attentional stability and task-focus). The aim of the study was to examine the influence of attentional focus instructions on skill acquisition and learning of an aiming task in individuals with hearing impairments. The participants (N = 39, Mage = 17.87 ± 1.88 years) performed a bowling task with their dominant hand to knock down as many pins as possible. On day 1, they were randomly divided into three attentional focus groups; IF (focus on your throwing hand), external focus (EF) (focus on the pins), and control (no-focus) instructions. Each participant performed 36 trials, divided into 3 blocks of 12 trials. Attentional focus instructions were given before each block, with a brief reminder provided after each 3 trials. On day 2, retention and transfer (further distance) tests were performed. Results showed that while there were no significant differences between groups in the pre-test, the EF group outperformed both IF and control groups in retention and transfer tests. No significant difference was found between the control and IF. The findings suggest that the advantages of the external relative to the IF and no-focus instructions may generalize to individuals with hearing impairments.

Anthropometric and biomechanical factors in elite male and female fast bowlers.

Researchers have extensively studied the biomechanics and anthropometrics of fast bowling in men's cricket, but there is still limited research in women's cricket. This study describes and compares the anthropometric qualities and bowling biomechanics between elite male and female fast bowlers. An inertial measurement system was used to collect three-dimensional biomechanical data for 20 elite fast bowlers (13 males and seven females). Kinematic data was captured at one step before back foot contact, back foot contact, front foot contact, ball release to one step after ball release. Anthropometric measurements included body segment lengths, mass, body fat (BF%) and muscle mass (MM%). The student t-test and Mann-Whitney U test were used for analyses. Hotelling's T2 statistic was calculated to control Type I error during multiple comparisons (p = 0.045). Males and females differed in overall height, limb length, BF% and MM%. Females presented with slower ball release speeds (p = 0.001). Biomechanically, the females were more front-on when approaching the delivery stride and then initiated pelvis and trunk rotation during the delivery stride, not seen in the males. Females and males have a similar magnitude of trunk side-flexion, but females present with a different strategy than males (p = 0.038). Females presented with increased front knee extension at ball release (p = 0.05). The findings from this study emphasise the differences between male and female fast bowlers and suggest that the coaching principles used in male fast bowling may not be relevant to female fast bowlers.

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.

Full-Body Kinematics and Vertical Ground Reaction Forces in Elite Ten-Pin Bowling: A Field Study.

The purpose was to investigate full-body kinematics and vertical ground reaction forces in the lower extremities of the delivery and to determine delivery changes over time after many deliveries in ten-pin bowling. Six male elite ten-pin bowlers completed six bouts of twelve bowling deliveries, all strike attempts, while measuring full-body kinematics and vertical ground reaction forces. Full-body joint angles, peak vertical ground reaction forces in the feet, vertical breaking impulse, centre of mass velocity, bowling score, and ball release velocity (BRvel) were measured. Results revealed that the BRvel was significantly decreased over bouts (p < 0.001). Additionally, increased flexion of the dominant wrist (p < 0.001) and elbow (p = 0.004) prior to ball release (BR) and increased pronation of the dominant wrist during BR (p = 0.034) were observed at later bouts. It was concluded that these kinematic changes in the dominant wrist and elbow prior to and during BR were performed to compensate for the change in traction between ball and lane during a bowling match. This, in turn, caused a decrease in BRvel. A conservation of energy perspective was discussed to highlight training applications and possibilities to enhance elite athletes' bowling performance.

Intrinsic variables associated with low back pain and lumbar spine injury in fast bowlers in cricket: a systematic review.

BACKGROUND: Lumbar spine injuries in fast bowlers account for the greatest missed playing time in cricket. A range of extrinsic and intrinsic variables are hypothesised to be associated with low back pain and lumbar spine injury in fast bowlers, and an improved understanding of intrinsic variables is necessary as these may alter load tolerance and injury risk associated with fast bowling. This review critically evaluated studies reporting intrinsic variables associated with low back pain and lumbar spine injury in fast bowlers and identified areas for future investigation. METHODS: OVID Medline, EMBASE, SPORTDiscus, CINAHL, Web of Science and SCOPUS databases were last searched on 3 June 2022 to identify studies investigating intrinsic variables associated with low back pain and lumbar spine injury in cricket fast bowlers. Terms relevant to cricket fast bowling, and intrinsic variables associated with lumbar spine injury and low back pain in fast bowlers were searched. 1,503 abstracts were screened, and 118 full-text articles were appraised to determine whether they met inclusion criteria. Two authors independently screened search results and assessed risk of bias using a modified version of the Quality in Prognostic Studies tool. RESULTS: Twenty-five studies met the inclusion criteria. Overall, no included studies demonstrated a low risk of bias, two studies were identified as moderate risk, and twenty-three studies were identified as high risk. Conflicting results were reported amongst studies investigating associations of fast bowling kinematics and kinetics, trunk and lumbar anatomical features, anthropometric traits, age, and neuromuscular characteristics with low back pain and lumbar spine injury. CONCLUSION: Inconsistencies in results may be related to differences in study design, injury definitions, participant characteristics, measurement parameters, and statistical analyses. Low back pain and lumbar spine injury occurrence in fast bowlers remain high, and this may be due to an absence of low bias studies that have informed recommendations for their prevention. Future research should employ clearly defined injury outcomes, analyse continuous datasets, utilise models that better represent lumbar kinematics and kinetics during fast bowling, and better quantify previous injury, lumbar anatomical features and lumbar maturation. TRIAL REGISTRATION: Open Science Framework https://doi.org/10.17605/OSF.IO/ERKZ2 .

Identification, Taxonomy and Performance Assessment of Type 1 and Type 2 Spin Bowling Deliveries with a Smart Cricket Ball.

Spin bowling deliveries in cricket, finger spin and wrist spin, are usually (Type 1, T1) performed with forearm supination and pronation, respectively, but can also be executed with opposite movements (Type 2, T2), specifically forearm pronation and supination, respectively. The aim of this study is to identify the differences between T1 and T2 using an advanced smart cricket ball, as well as to assess the dynamics of T1 and T2. With the hand aligned to the ball's coordinate system, the angular velocity vector, specifically the x-, y- and z-components of its unit vector and its yaw and pitch angles, were used to identify time windows where T1 and T2 deliveries were clearly separated. Such a window was found 0.44 s before the peak torque, and maximum separation was achieved when plotting the y-component against the z-component of the unit vector, or the yaw angle against the pitch angle. In terms of physical performance, T1 deliveries are easier to bowl than T2; in terms of skill performance, wrist spin deliveries are easier to bowl than finger spin. Because the smart ball allows differentiation between T1 and T2 deliveries, it is an ideal tool for talent identification and improving performance through more efficient training.

Lumbar Spine Injury in Indian Fast Bowlers: 3D Biomechanical Analysis and Prevention Strategies.

Background: Lumbar spine injuries are among the most common overuse injuries in a fast bowler. Among various causative factors, bowling action technique is a crucial one. Three-dimensional motion analysis has been accepted as a gold standard tool to identify incorrect techniques. Previous studies have identified key biomechanical variables associated with lumbar injury risk in fast bowlers. Despite the large popularity of the sport, there is limited information available on the subject in Indian fast bowlers. This study aims to analyse the lumbar spine injury risk in Indian fast bowlers with respect to key biomechanical variables, using 3D motion analysis. Methods: Forty-seven male first class fast bowlers underwent 3D motion analysis in an indoor biomechanics laboratory. Motion capture was done with 3D cameras and 2D video cameras, using a standard marker set. Data processing and analysis was done using proprietary software. Biomechanical variables associated with lumbar spine injury risk including lateral trunk flexion (LTF) and knee angle at front foot contact (KA at FFC) were measured, and peak vertical ground reaction forces (pVGRF) were simultaneously recorded using force plates. Descriptive analysis of the data was done. Results: 26% of bowlers had a high LTF, 29% had low KA at FFC and 43% had high pVGRF. Thus, a large proportion of bowlers in this study were at risk of lumbar spine injury with respect to the assessed variables. Conclusion: This highlights the role of 3D motion analysis in early identification of injurious techniques, which can be modified by coaching and training interventions to prevent injuries. This study thus has implications on coaching and training of fast bowlers in India.

Bone health and asymmetry in elite female cricketers.

The aim of this study is to determine if bone mineral density (BMD) and bone asymmetry differs between female cricket fast bowlers, spin bowlers and batters. BMD was determined at the total body, lumbar spine, and proximal femurs in 12 fast bowlers, 13 batters and 11 spin bowlers from pre-season DXA scans. High Z-scores at the total body, lumbar spine, and proximal femur were observed in all cricketers (mean Z-scores: +1.4 to +3.3) compared with a general age matched reference population. Fast bowlers had significantly greater BMD on the contralateral side of the lumbar spine compared with the ipsilateral side (p = 0.001, 5.9-12.1%). No asymmetry was found between hips in all groups. All cricket positions demonstrated high BMD at all measured sites. The lumbar spine of fast bowlers is asymmetric, with significantly greater BMD on the contralateral side of the spine, particularly at L4, possibly in response to the asymmetric lumbar loading patterns observed in bowling.HighlightsElite female cricketers demonstrate high BMD at total body, lumbar spine and proximal femur sites, regardless of playing position compared with a general age and ethnic group matched reference population.Fast bowlers have greater BMD on the contralateral (opposite bowling arm) side of the lumbar spine compared with the ipsilateral side, while a symmetrical pattern was observed in spin bowlers and batters.No asymmetry in BMD or section modulus between hips was observed at any proximal femur site for any cricket position.

Female cricket pace bowling: kinematic and anthropometric relationships with ball release speed.

Background: Despite an increase in the professionalism and participation of female cricket, the coaching of female pace bowling is still reliant on male-derived knowledge. Objectives: To investigate the association between key male-derived kinematic and anthropometric parameters and ball release speed (BRS) in female pace bowlers. Methods: Eleven female pace bowlers participated in this study. BRS, and four anthropometric and five kinematic parameters were determined. Stepwise linear regression and Pearson Product Moment correlations were used to identify anthropometric and kinematic parameters linked to BRS. Results: The best predictor of BRS explaining 89% of the observed variance was the bowling shoulder angle at ball release. The best anthropometric predictor of BRS was height explaining 53% of the observed variance. Other parameters correlated with BRS included: run-up speed (r = 0.75, p = 0.013) and arm length (r = 0.61, p = 0.046). When height was controlled for, the front knee angle at front foot contact was also correlated to BRS (r = 0.68, p = 0.044). No relationship was found between trunk flexion and BRS. Conclusion: Faster BRS were characterised by faster run-up speeds, straighter front knees, and delayed arm circumduction similar to male pace bowlers. The lack of relationship between trunk flexion and BRS may highlight female pace bowlers adopting a bowling technique where BRS is contributed to by trunk rotation as well as trunk flexion. This knowledge is likely to be useful in the talent identification and coaching of female pace bowlers.

Management of lumbar bone stress injury in cricket fast bowlers and other athletes.

Background: Recent guidelines (including a special series in The Lancet) have emphasised a minimal role for imaging when assessing low back pain in adults, as the majority of patients will have non-specific findings on imaging that do not correlate well with pain. Objective: To assess whether the diagnosis of lumbar bone stress injuries in young athletes should be considered an exception to the recommendation to avoid imaging for low back pain in adults. Method: Narrative review. Results: Early lumbar bone stress injury diagnosis has been available via traditional MRI sequences (and its precursor Single Photon Emission Computed Tomography (SPECT)) for 25-30 years. MRI assessments using bone window sequences (such as Volumetric Interpolated Breath-hold Examination (VIBE)) have allowed a better understanding of the diagnosis and prognosis of lumbar bone stress injury in young athletes. MRI with bone sequences has allowed non-radiating scans to serially follow the healing of unilateral stress fractures. In the majority of cases, non-chronic unilateral fractures can heal; however, this takes three-six months rather than the six-ten weeks that would be the typical unloading period if using symptoms (only) as a guide. The use of MRI to provide evidence of bony healing (as opposed to fibrous union, which creates the pars defect that predisposes to further bone stress lesions) can lead to better long-term outcomes in athletes. There is evidence to flag this as a structural lesion which is both painful and, more importantly, can heal/resolve if managed correctly. Therefore it represents an important 'specific' diagnostic subset within adult low back pain. Conclusion: Structural (rather than functional) management of bone stress injuries in high-demand athletes, such as cricket pace bowlers, is in contrast to the recommendation of functional management for general back pain in adults. Structural management is justified when there are demonstrable superior outcomes of having better structure. Although this has not yet been shown in randomised trials of elite athletes, apparent lengthier Test cricket careers of pace bowlers who do not have pars defects suggest better athletic outcomes if bony healing is achieved. For lower demand young adults, or athletes with established bilateral pars defects, functional management may be more pragmatic.

Effect of Indian clubbell exercises on cricket fast bowlers' shoulder kinematics.

Background: The glenohumeral joint's rotational range of motion (ROM) and muscle strength are essential to execute the cricket bowling action. Performing shoulder rotation exercises may increase the rotator cuff muscle strength and rotational ROM. Objectives: The aim of this study was to test the effect of a six-week exercise programme on shoulder rotational ROM and muscle strength. Methods: Twenty-one healthy male cricket fast bowlers were recruited, ranked and pair-matched on initial shoulder rotator muscle strength and assigned to either a shoulder exercise (SE) group or cricket training (CT) only group. The SE group incorporated Indian clubbell exercises in addition to their cricket training. Results: Bowlers in both groups displayed a large increase on the dominant shoulder's internal rotation (IR) ROM, but only the SE group's bowlers displayed ROM improvements (p<0.001) bilaterally for both internal and external rotation. The CT group's fast bowler's non-dominant shoulder IR ROM significantly decreased (p=0.02) during the six weeks. Between groups, only the SE group's bowler's internal rotator muscle strength improved (p<0.001) bilaterally. The observed kinematic changes were statistically significantly greater at a 5% level for the SE group's bowlers (bilateral internal rotators muscle strength, non-dominant shoulder IR ROM and horizontal adduction ROM). Conclusion: Maintenance of the shoulder's rotational ROM and muscle strength is vital for a fast bowler. Cricket bowlers who perform regular clubbell exercises might increase their shoulder's ROM and internal rotator cuffs' muscle strength, which may aid in stabilising their glenohumeral joint while bowling.

The Physical Qualities of Elite Australian Pace Bowlers: Typical Characteristics and Longitudinal Changes in Men and Women.

PURPOSE: To determine whether the most important physical qualities in elite Australian male and female cricket pace bowlers change with age and phase of the cricket season. METHODS: An existing longitudinal database (7 cricket seasons) of selected and routinely collected physical testing data from 103 male and 58 female elite Australian pace bowlers age 18-30 years was retrospectively analyzed. Male and female physical testing data from the isometric midthigh pull, 1-repetition-maximum bench pull, run-of-3, and countermovement jump (male only) were analyzed separately by performing linear mixed models on each of the physical qualities. Type III analysis-of-variance tests were conducted to determine if a significant effect existed within the fixed effects of age, season phase, and the age × season phase interaction. Appropriate pairwise comparisons were conducted. RESULTS: Absolute and relative measures of force in the isometric midthigh pull and strength in the 1-repetition-maximum bench pull tests were significantly greater in older male and female pace bowlers. Older male pace bowlers demonstrated significantly faster absolute and relative best run-of-3 times. CONCLUSIONS: Most physical qualities across both male and female pace bowlers demonstrated an improvement with age. This is likely due to a training effect and would be anticipated to lead to a gradual enhancement of ball release speed, in accordance with previous research. Future research should look to investigate the relationship between the development of physical qualities and ball release speed among elite male and female pace bowlers.

Comparing tibial accelerations between delivery and follow-through foot strikes in cricket pace bowling.

Foot strikes of the pace-bowling delivery stride produce large ground reaction forces, which may be linked to injury, yet the biomechanics of the follow-through are unknown. This study assessed tibial accelerations across the delivery and follow-through foot strikes in pace bowlers and evaluated relationships between these measures and five common pace-bowling intensity metrics. Fifteen sub-elite male pace bowlers performed deliveries at warm-up, match, and maximal intensities. Tibial accelerations were measured using tibial-mounted inertial measurement units and recorded at back- and front-foot initial and re-contacts. A trunk-worn global navigation satellite system unit measured PlayerLoad™, run-up speed, and distance. Ball speed and perceived exertion measures were also recorded. A linear mixed model showed statistical significance of prescribed intensities (p < .001) and foot strike for tibial acceleration (p < .001). Tibial accelerations showed positive increases with changes in prescribed intensity (p < .05). The greatest magnitude of tibial acceleration was found at back foot re-contact (mean ± SD; 1139 ± 319 m/s2). Repeated-measures correlations of tibial acceleration between foot contacts were weak (r = 0.2-0.4). The greatest magnitude of tibial acceleration reported at back foot re-contact may have implications for injury incidence, representing an important avenue for future pace bowling research.

Who Believes in the Species? Three-Factor Structure and Heritability of Generativity.

Erikson asked what makes some people care for the future of the species and others not, calling this 'generativity vs. stagnation'. In three studies, we addressed structure of this trait and its heritability. Study 1 (N = 1570), using structural models of the Loyola Generativity Scale , revealed three correlated factors consisting of (1) Establishing and aiding the next generation; (2) Maintaining the world; and (3) Symbolic immortality through a positive legacy. Study 2 (N = 311) successfully replicated this structure in an independent UK sample. Study 3 tested genetic and environmental influences on generativity. All three factors showed significant and substantial heritable influence. A general factor was required, which was also heritable. In resolving previous uncertainty over the transmission of generativity across generations, shared environmental transmission models fit poorly. Substantial unique environmental effects suggest strong cultural impacts on concern for the species. Generativity researchers may usefully adopt this three-factor scoring system, allowing research on the predictive power of each component of generativity as well as molecular genetic or biological studies.

The Physical Differences Between Faster and Slower Elite Male and Female Pace Bowlers.

PURPOSE: This study investigated the differences between selected physical attributes and ball release speed in slower and faster male and female elite pace bowlers. METHODS: Twelve physical attributes and ball release speed were retrospectively analyzed from 63 male and 31 female elite pace bowlers over the course of 5 seasons. Pace bowlers were categorized as either fast (>122.9 km/h, males and >97.8 km/h, females) or slow (<122.9 km/h, males and <97.8 km/h, females) for each sex. Differences in physical attributes between slower and faster bowling groups were compared using Cohen d effect sizes. RESULTS: Faster pace bowlers displayed differences in isometric midthigh-pull peak force (d = 0.25, males and d = 0.68, females) and relative peak force (d = 0.62, males and d = 0.77, females). Faster male pace bowlers displayed differences in relative (d = 0.61) and absolute (d = 0.39) countermovement jump heights. Faster female pace bowlers displayed differences in 1-repetition-maximum bench-pull strength (d = 0.45) and run-of-3 performance (relative average, d = 1.22; relative best, d = 1.12; average, d = 0.49; and best, d = 0.40). CONCLUSIONS: Anaerobic dominant physical attributes appear to be important in both male and female pace bowlers. The contribution of these physical attributes to ball release speed appears to differ slightly between males and females. Lower-body strength (males and females), lower-body power (males), relative anaerobic capacities (females), and upper-body strength (females) appear to distinguish between slower and faster elite pace bowlers.

Relative Age Effects in Male Cricket: A Personal Assets Approach to Explain Immediate, Short-Term, and Long-Term Developmental Outcomes.

The purpose of this study was to adopt the Personal Assets Framework (PAF) to examine the immediate, short-term, and long-term developmental outcomes associated with relative age effects (RAEs) in male cricket. As such, this study was comprised of three aims: (a) examine the birth quarter (BQ) distribution of players throughout the England and Wales Cricket Board (ECB) national talent pathway (i.e., Regional U15, Regional U17, England U19, England Lions, England T20, England ODI, and England Test; n = 1800; immediate timescale), (b) explore the youth-to-senior transitions based on BQ and skill-set (i.e., batters and bowlers; short-term timescale), and (c) analyse the average number of games played at senior levels based on BQ and skill-set (i.e., long-term timescale). A chi-square goodness of fit test, Cramer's V, odds ratios, and 95% confidence intervals were used to compare the BQ distributions of each cohort against the expected BQ distributions. In the immediate timescale, results showed that relatively older players were overrepresented throughout all the youth levels (p < 0.05, V = 0.16−0.30), whereas there were no differences at senior levels (p > 0.05, V = 0.05−0.15). In the short-term timescale, when the senior cohorts were compared to the expected BQ distributions based on the Regional U15 cohort, relatively younger players were more likely to transition from youth to senior levels (p < 0.05, V = 0.22−0.37). In the long-term timescale, relatively older batters were selected for more games (p < 0.05, V = 0.18−0.51), whereas relatively younger bowlers were selected for more games (p < 0.05, V = 0.17−0.39). Moving forward, it is important for researchers and practitioners to better understand how (bi)annual-age grouping shapes developmental outcomes in across different timescales (i.e., immediate, short-term, and long-term), as well as consider alternative grouping strategies and RAE solutions.

Fortalecimento do rotador interno do ombro versus técnica de energia muscular para rotadores externos do ombro na velocidade de lançamento em jogadores rápidos que jogam críquete - um estudo quase-experimental / Shoulder internal rotator strengthening vs. muscle energy technique for shoulder external rotators on bowling speed in fast bowlers playing cricket - a quasi-experimental study

INTRODUÇÃO: A articulação do ombro é a articulação mais complexa do corpo humano, a mais móvel e menos estável em relação às outras articulações. No lançamento, usar a extremidade superior no movimento de arremesso é uma das tarefas mais desafiadoras. Para gerar um arremesso preciso, os numerosos componentes anatômicos envolvidos no movimento de arremesso acima da cabeça devem ser coordenados. A força muscular do ombro é um componente-chave para excelência no lançamento, e a força de vários grupos musculares do ombro influencia a velocidade do lançamento. Por isso, é fundamental que os jogadores de lançamento exerçam força em seu desempenho. Isso carece de estabilidade óssea e sacrifica a estabilidade para aumentar a mobilidade. OBJETIVOS: Analisar os efeitos do fortalecimento dos rotadores internos do ombro e da técnica de energia muscular (TEM) dos rotadores externos do ombro na velocidade de arremesso em jogadores rápidos de críquete. MATERIAIS E MÉTODOS: Jogadores de críquete rápido participantes de campo esportivo, com idade entre 18 e 30 anos, foram recrutados e então alocados aleatoriamente em dois grupos: grupo fortalecimento e grupo TEM. O grupo fortalecimento recebeu fortalecimento muscular para os rotadores internos do ombro e o grupo TEM recebeu a técnica de energia muscular para os rotadores externos. Todas as intervenções de exercícios envolveram sessão de supervisão do fisioterapeuta com 12 repetições e 3 séries 5 dias por semana até oito semanas. A amplitude de movimento foi medida pelo goniômetro e a velocidade do arremesso foi avaliada pela pistola de velocidade. Todos os resultados foram avaliados na linha de base, 2ª semana, 4ª semana e 8ª semana após a intervenção com a ANOVA de medidas repetidas. RESULTADOS: Dos 30 participantes avaliados, a média de idade, altura, peso e IMC foi, respectivamente, 21.40±2.36 anos de idade, 1.74±.09m, 71.80±16.77kg e 23.57±4.20Kg/m2 para o grupo fortalecimento e 22.53±1.55 anos, 1.70±.04m, 62.47±8.02kg, 21.49±2.63 Kg/m2 para o grupo TEM. Houve diferença estatisticamente significante para todos os desfechos em relação aos tempos medidos entre os dois grupos de intervenção. Porém, no grupo fortalecimento, houve maior tamanho de efeito para ADM de Rotação Interna (1.99 no grupo fortalecimento versus 1.42 no grupo TEM) e para velocidade do arremesso (1.52 versus 1.39). A ADM de rotação externa obteve maior tamanho de efeito no grupo TEM (1.66 para o grupo TEM e 1.16 para o grupo fortalecimento). CONCLUSÕES: O resultado do estudo conclui que uma melhora significativa na força dos rotadores internos e externos do ombro leva a uma melhora na velocidade do lançamento, de modo que o protocolo de treinamento de força do ombro e o treinamento de energia muscular podem ser incorporados para aumentar a velocidade do jogador.

INTRODUCTION: The shoulder joint is the most complex joint in the human body, the most mobile and least stable in relation to other joints. In bowling, using the upper extremity in the throwing motion is one of the most challenging tasks. In order to generate a precise throw, the numerous anatomical components involved in the overhead throwing motion must be coordinated. Shoulder muscular strength is a key component of excellent bowling, and the strength of various shoulder muscle groups influences bowling speed. Therefore, bowling players must exert strength in their performance. This lacks bone stability and sacrifices stability to increase mobility. OBJECTIVES: To analyse the effects of strengthening the shoulder internal rotators and the muscular energy technique of the shoulder external rotators on bowling speed in fast cricket players. METHODS AND MATERIALS: Participating rapid cricket players from the sports field, aged 18- 30 years, were recruited and then randomly allocated into two groups: the strengthening group and the MET group. The strengthening group received muscle strengthening for the shoulder's internal rotators, and the MET group received the muscle energy technique for the external rotators. All the exercise interventions were involved physiotherapist supervision sessions with 12 repetitions and 3 sets 5 days per week up to eight weeks. Range of motion was measured by goniometer instrument, and bowling speed was assessed by speed gun. All outcomes were assessed at baseline, 2nd week, 4th week, and 8th week after the intervention with repeated measures ANOVA. RESULTS: Of the 30 participants evaluated, the mean age, height, weight, and BMI were, respectively, 21.40±2.36 years old, 1.74±0.09m, 71.80±16.77kg, and 23.57±4.20Kg/m2 for the strengthening group and 22.53±1.55 years old, 1.70±0.04m, 62.47±8.02kg, 21.49±2.63Kg/m2 for the MET group. There was a statistically significant difference for all outcomes regarding the measured times between the two intervention groups. However, there was a greater effect size for internal rotation ROM (1.99 in the strengthening group versus 1.42 in the MET group) and bowling speed (1.52 versus 1.39) in the strengthening group. External rotation ROM had a greater effect size in the MET group (1.66 for the MET group and 1.16 for the strengthening group). CONCLUSIONS: The study concludes that a significant improvement in shoulder internal rotators and external rotators' strength leads to improved bowling speed, so the shoulder strength training protocol and muscle energy training can be incorporated for increasing the bowler's speed.

Measurement of uni-planar and sport specific trunk motion using magneto-inertial measurement units: The concurrent validity of Noraxon and Xsens systems relative to a retro-reflective system.

BACKGROUND: There is a range of magneto-inertial measurement unit (MIMU) systems commercially available, however sensor specifications and fusion methods vary considerably between manufacturers. Such variability can influence the concurrent validity of MIMUs relative to reference standard measurement devices. Different MIMUs have been compared during static or low-velocity conditions, with higher-velocity movements assessed in robotic-based studies. However, there is a need for the concurrent validity of higher-velocity movements to be established in human-based studies. RESEARCH QUESTION: This study aimed to assess the concurrent validity of two commercial MIMU systems (Noraxon and Xsens), relative to a 'gold-standard' retro-reflective motion capture system, when measuring trunk angles during uni-planar range of motion (ROM) and cricket bowling, which involves high-speed, multi-planar movements. METHODS: For this criterion-based validity study, both MIMU systems incorporated comparable sensor specifications and employed Kalman filter sensor fusion algorithms. The MIMU based angles were compared with angles derived from concurrently captured three-dimensional retro-reflective data for 10 fast-medium bowlers. Statistical parametric mapping and root mean squared differences (RMSD) were computed for both MIMU systems. RESULTS: One-dimensional statistical parametric mapping showed no significant differences for angles from both MIMU systems when compared with retro-reflective based angle outputs. The MIMU systems produced ROM RMSDs between 1.4 ± 1.0° and 2.6 ± 1.5°. One system displayed RMSDs between 4.6 ± 1.4° and 7.4 ± 1.9° during bowling, indicating functionally relevant differences to retro-reflective derived angles. There were some small but statistically significant differences in RMSDs between the MIMU systems. SIGNIFICANCE: MIMU-based angle accuracy is poorer during high-speed, multi-planar movement than uni-planar tasks. Comparable MIMU systems can produce varying measurements during ROM and bowling tasks. It is likely that varying sample rates and sensor fusion algorithm parameters contributed to the differences.

The core of performance in adolescent cricket pace bowlers: Trunk muscle stability, maybe, but not strength-endurance and thickness.

Background: The trunk connects the upper and lower limbs and transfers energy during movement. Exploring the role of the trunk muscles in bowling performance affords us the opportunity to uncover potential mechanisms to improve bowling performance. Objectives: To investigate the association between bowling performance and trunk muscle stability, strength-endurance and thickness in adolescent pace bowlers. Methods: Adolescent pace bowlers participated in this cross-sectional study. Trunk muscle stability was measured using Sahrmann's Stability Scale, strength-endurance using the Bourbon Trunk Muscle Strength Test and thickness of the abdominal wall and lumbar multifidus muscles using ultrasound imaging. Results: Forty-six pace bowlers with a mean age of 15.9 ±1.2 years participated. The average ball release speed was 109.2±11.8 km.h-1. This measurement was higher in level four of stability than in level two (mean difference 22.2 ± SD 6.8 km.h-1; p= .018). No link between ball release speed and strength-endurance could be found. Multiple correlations of moderate strength (r > 0.4) exist between ball release speed and absolute trunk muscle thickness with height and weight as confounding factors. The relationship between accuracy and the trunk muscle variables investigated in this study is weak. Conclusion: Bowlers with better trunk muscle stability bowled faster than those with a lower level of trunk stability, irrespective of their age, height and weight. Trunk muscle thickness correlated with ball release speed; however, confounding factors such as height and weight play a role and therefore, findings need to be interpreted with caution.

Quantifying cricket fast bowling volume, speed and perceived intensity zone using an Apple Watch and machine learning.

This study examined whether an inertial measurement unit (IMU) and machine learning models could accurately measure bowling volume (BV), ball release speed (BRS), and perceived intensity zone (PIZ). Forty-four male pace bowlers wore a high measurement range, research-grade IMU (SABELSense) and a consumer-grade IMU (Apple Watch) on both wrists. Each participant bowled 36 deliveries, split into two different PIZs (Zone 1 = 70-85% of maximum bowling effort, Zone 2 = 100% of maximum bowling effort). BRS was measured using a radar gun. Four machine learning models were compared. Gradient boosting models had the best results across all measures (BV: F-score = 1.0; BRS: Mean absolute error = 2.76 km/h; PIZ: F-score = 0.92). There was no significant difference between the SABELSense and Apple Watch on the same hand when measuring BV, BRS, and PIZ. A significant improvement in classifying PIZ was observed for IMUs located on the dominant wrist. For all measures, there was no added benefit of combining IMUs on the dominant and non-dominant wrists.