Asymmetry in internal oblique muscle thickness: Not the key to a cricket fast bowler's performance

Purpose Previous studies found that trunk muscle asymmetry may play a role in preventing injury in cricket fast bowlers, while the association with bowling performance has not been investigated. This study aims to describe the side-to-side differences in trunk muscle thickness and determine the association between bowling performance and these side-to-side differences in trunk muscle thickness in adolescent fast bowlers. Methods In this observational cross-sectional study, bowling performance, namely ball release speed and bowling accuracy, was recorded in adolescent fast bowlers. Ultrasound imaging measured external oblique, internal oblique, transversus abdominis and lumbar multifidus muscle thickness. Results Fast bowlers (n = 46) with a mean age of 15.9 (±1.2) years participated. On the non-dominant side, the external oblique and internal oblique at rest were thicker than on the dominant side (external oblique: p = 0.011, effect size = 0.27; internal oblique: p < 0.0001, effect size = 0.40), while the transversus abdominus ( p = 0.72, effect size = 0.19) and lumbar multifidus ( p = 0.668, effect size = 0.04) were symmetrical. Weak correlations existed between bowling performance and the side-to-side differences in the thickness in all muscles, except for two moderate correlations: 1. The smaller the side-to-side difference in absolute thickness of the external oblique when contracted, the faster the ball release speed (Spearman's (ρ) = −0.455, p = 0.002). 2. Also, a smaller side-to-side difference in external oblique contraction ratio (Spearman's (ρ) = −0.495, p = 0.0001) was associated with faster ball release speed. Conclusions No relationship between bowling performance and side-to-side differences in internal oblique muscle thickness could be established, while more symmetrical external oblique muscles may be linked to faster ball release speeds.

Motion Analysis Focusing on Rotational Movements of Professional Female Baseball Pitchers: Comparison with Male University Baseball Pitchers

Purpose: The purpose of this study was to compare pitching motion of the professional female baseball pitchers with the male university baseball pitchers focused on the pelvic and thoracic movements. Subjects and methods: The participants were 15 healthy professional female baseball pitchers (11 right-handers and 4 left-handers; age, 21.7 ± 3.2 years; height, 162.5 ± 5.1 cm; weight, 59.0 ± 6.6 kg) and 14 healthy male university baseball pitchers (12 right-handers and 2 left-handers; age, 19.9 ± 0.8 years; height, 176.4 ± 3.0 cm; body mass, 73.1 ± 3.0 kg). Throwing motion was captured by three-dimensional motion analysis system. Kinematic data of the lead hip, pelvis, thorax, and dominant shoulder were collected and the joint angle at maximum external rotation phase and ball release phase were compared. Results: The female baseball pitchers rotated pelvis and thorax more than the male at the maximum external rotation phase and ball release phase (p < 0.05). At the same, the pelvis and thorax of the female baseball pitchers were tilted significantly closer to horizontal plane than the male (p < 0.05). The pelvis and thorax of the male baseball pitchers was tilted to non-dominant lateral side. Conclusions: The results of this study indicate that the pelvic and thoracic movements of the professional female baseball pitchers was different from male university pitchers.

Free throw technical analysis and its relationship with success in Under-12 basketball players (Análisis técnico de los tiros libres y su relación con el éxito en jugadores de baloncesto menores de 12 años)

The aim of this study was to determine the free throw technique and successful free throw technique both prior to ball release and at ball release moments in under-12 basketball, using a court-applied test. The participants were 102 players from eight male under-12 officially federated basketball teams. We used a point/ideographic/multidimensional observational design to analyse the recordings of 612 free throws. The test consisted of performing one, two or three free throws. One participant performed the free throws and the other passed the ball to him. The roles were exchanged until the two participants performed all the free throw options. As a result, the participants did not execute the free throw using the technique proposed by the literature. This difference was because jumping free throws shoots, with low style, feet at the same distance, and moderate forward displacement of the centre of mass predominated. The free throw technique was in general more regular than that of the successful free throws. Players used an unregulated technique, without meeting the criteria that activate success in the free throw. This technique resulted attempting successful free throws at 4 m from the basket, which is 2.60 m high, with a 485-g ball. Taking into account the characteristics of the participants of the present work in terms of age, strength, maturity, height, weight, and body mass index, coaches and the competition managers should assess what should be improved in under-12 basketball to allow players to increase free throw success. Resumen: El objetivo de este estudio fue determinar la técnica de tiro libre y la técnica de tiro libre con éxito, tanto antes de la salida del balón como en el momento de salida del balón en baloncesto U-12, a través de un test de tiro. Los participantes fueron 102 jugadores de ocho equipos masculinos de baloncesto U-12 federados. Se utilizó un diseño observacional puntual/ideográfico/multidimensional para analizar las grabaciones de 612 tiros libres. La prueba consistía en realizar uno, dos o tres tiros libres. Un participante realizaba los tiros libres y el otro le pasaba el balón. Los participantes intercambiaban los roles hasta que los dos realizaron todas las opciones de tiro libre. Los resultados mostraron que los participantes no ejecutaron el tiro libre utilizando la técnica propuesta por la literatura. Esta diferencia se debió a que predominaron los tiros libres con salto, con estilo bajo, pies a la misma distancia y desplazamiento moderado del centro de masas hacia adelante. La técnica de los tiros libres en general fue más regular que la de los tiros libres con éxito. En conclusión, los jugadores utilizaron una técnica alejada de las recomendaciones teóricas, poco regular, y sin cumplir los criterios que posibilitan éxito en el tiro libre. Esto ocurrió como consecuencia de intentar obtener éxito en una situación de tiro libre a 4 m de la canasta, situada a 2.60 m de altura, y con un balón de 485 g. Teniendo en cuenta las características de los participantes del presente trabajo en cuanto a edad, fuerza, madurez, altura, peso e índice de masa corporal, los entrenadores y los responsables de las competiciones deberían valorar qué debe mejorarse en el baloncesto U-12 para que los jugadores puedan aumentar el éxito en los tiros libres.

Effects of a self-training program on shooting performance and kinematics in young basketball players: a case study (Efectos de un programa de autoentrenamiento sobre el rendimiento y cinemática de tiro en jóvenes jugadores de baloncesto: un caso de estu

The current study intended to investigate the effects of a self-training program on shooting performance and kinematics of young basketball players. Fourteen male basketball players aged 16.64±.50 years, divided in control group (n=7) and experimental group (n=7), were assessed on free-throw, two-point and three-point shooting performance and on four kinematic parameters (release height, release angle, release speed and trajectory variability), before and after a five-week training program. During the five-week period, the experimental group accomplished a shooting training program that included 600 shots per week. Both groups maintained their regular basketball practice. The results show that the experimental group significantly increased their shooting performance on three-point (p<.05) and on free-throw (p<.05). Moreover, a significant decrease in three-point ball release angle (p<.05) and a significant increase in free-throw ball release height (p<.05) were observed in the experimental group, while the control group significantly increased the two-point ball release speed (p<.05). In conclusion, self-shooting basketball practice, in addition to formal practice, significantly improves shooting performance of young basketball players. In contrast, the reduced changes on the analysed kinematic parameters caused by the self-training program are most likely a consequence of the absence of external feedback during training process. Resumen. El propósito del presente estudio fue investigar los efectos de un programa de autoentrenamiento en el rendimiento y cinemática de tiro de jóvenes jugadores de baloncesto. Catorce jugadores de baloncesto masculinos, de 16.64±0.50 años, divididos en grupo de control (n=7) y grupo experimental (n=7), fueron evaluados en el rendimiento de tiro libre, de dos puntos y de tres puntos y en cuatro parámetros cinemáticos (altura de liberación, ángulo de liberación, velocidad de liberación y variabilidad de la trayectoria), antes y después de un programa de entrenamiento de cinco semanas. Durante el período de cinco semanas, el grupo experimental realizó un programa de entrenamiento de tiro que incluía 600 tiros por semana. Ambos grupos mantuvieron su práctica regular de baloncesto. Los resultados muestran que el grupo experimental aumentó significativamente su rendimiento en el tiro de tres puntos (p<.05) y en el tiro libre (p<.05). Además, se observó, en el grupo experimental, una disminución significativa del ángulo de liberación en el tiro de tres puntos (p<.05) y un aumento significativo de la altura de liberación en el tiro libre (p<.05), mientras que el grupo de control aumentó significativamente la velocidad de liberación en el tiro de dos pontos (p<.05). En conclusión, la autopráctica de tiro en baloncesto, además de la práctica formal, mejora significativamente el rendimiento de tiro de los jugadores jóvenes. Por el contrario, los cambios reducidos en los parámetros cinemáticos analizados son probablemente una consecuencia de la ausencia de corrección externa durante el proceso de autoentrenamiento.

The effects of a four weeks combined resistance training programme on cricket bowling velocity

Background: Despite the importance of resistance training for cricket pace bowlers, there is limited research displaying meaningful improvements in ball release velocity following resistance training. Objectives: The study aimed at investigating the effects of a four weeks combined resistance training programme on ball release velocity in club cricket pace bowlers. Methods: Eighteen adult male club level pace bowlers were allocated into a combined resistance training (CRT) group or a traditional cricket training (TR) group. The CRT group (n=9) performed two training sessions a week for four weeks, consisting of a combination of core and lower body strength exercises, plyometric exercises, and weighted implement training. The TR group (n=9) did no resistance training and only bowled with regular weighted cricket balls. Pre- testing/post-testing variables were ball release velocity, bowling accuracy, and upper and lower body neuromuscular performance. Results: The CRT group significantly increased their ball release velocity by six percent (5.1 km·h-1), effect size (ES) =0.65, p<0.001) after four weeks of training, while there was no significant difference in the TR group (0.00 km·h-1, ES=0.0, p=0.674). There was no statistically significant difference in the bowling accuracy and lower body neuromuscular performance for both groups and the upper body neuromuscular performance for the CRT group. Conclusion: This study provides evidence of a combined resistance training programme that can be used to improve bowling velocity in cricket pace bowlers. This increase in ball velocity was not related to any of the neuromuscular performance variables measured.

The influence of shoulder abduction and external rotation on throwing arm kinetics in professional baseball pitchers

Background The relationships between shoulder abduction and external rotation with peak kinetic values at the shoulder and elbow in professional baseball pitchers are not well established. Methods Professional pitchers ( n = 322) threw 8–12 fastballs under 3D motion analysis (480 Hz). Pitchers were stratified into quartiles by shoulder abduction and external rotation at distinct timepoints. Regression analyses were performed to quantify associations between shoulder position and kinetics. Results Shoulder abduction remained relatively consistent throughout the pitch (foot contact–ball release: 85.5 ± 11.1–90.7 ± 8.4°); shoulder external rotation increased dramatically (foot contact–ball release: 30.8 ± 24.6–165.2 ± 9.7°). For every 10° increase in maximum shoulder rotation, shoulder superior force increased by 2.3% body weight ( p < 0.01), shoulder distraction force increased by 5.9% body weight ( p < 0.01), and ball velocity increased by 0.60 m/s ( p < 0.01). Shoulder abduction was significantly associated with shoulder superior force at all timepoints but not with ball velocity ( p > 0.05). For every 10° increase in shoulder abduction at ball release, shoulder superior force increased by 3.7% body weight ( p < 0.01) and shoulder distraction force increased by 11.7% body weight ( p < 0.01). Conclusion Increased shoulder abduction at ball release and increased maximum shoulder external rotation were associated with greater superior and distraction forces in the shoulder. Pitchers can consider decreasing shoulder abduction at later stages of the pitch to around 80° in order to minimize shoulder superior force, with no impact on ball velocity.

Shadow pitching deviates ball release position: kinematic analysis in high school baseball pitchers

Background Although shadow pitching, commonly called “towel drill,” is recommended to improve the throwing motion for the rehabilitation of pitching disorders before the initiation of a throwing program aimed at returning to throwing using a ball, the motion differs from that of normal throwing. Learning improper motion during ball release (BR) may increase shoulder joint forces. Abnormal throwing biomechanics leads to injures. However, there has been no study of shadow pitching focusing on the BR position. The purpose of the present study was to evaluate the BR position and kinematic differences between shadow pitching and normal throwing. In addition, the effect of setting a target guide for BR position on throwing motion was examined in shadow pitching. Methods The participants included in this study were 20 healthy male students who were overhand right-handed pitchers with no pain induced by a throwing motion. Participants performed normal throwing (task 1), shadow pitching using a hand towel (task 2), and shadow pitching by setting a target of the BR position (task 3). A motion capture system was used to evaluate kinematic differences in throwing motions, respectively. Examination items comprised joint angles and the differences in BR position. Results BR position of task 2 shifted significantly toward the anterior, leftward, and downward directions compared with task 1. The distance of BR position between tasks 1 and 2 was 24 ± 10%. However, task 3 had decreased BR deviation compared with task 2 (the distance between 3 and 1 was 14 ± 7%). Kinematic differences were observed among groups at BR. For shoulder joint, task 2 showed the highest value in abduction and horizontal adduction among groups. In spine flexion, left rotation and thorax flexion, task 2 was significantly higher than task 1. Task 3 showed small differences compared with task 1. Conclusions The BR position of shadow pitching deviated significantly in the anterior, leftward, and downward directions compared with normal throwing. Furthermore, we demonstrated that the setting of BR target reduces this deviation. Thus, the target of BR position should be set accurately during shadow pitching exercises in the process of rehabilitation.