Joint Coordination With a Change in Task Constraint During Accurate Overhead Throwing.

In sports situations, players may be required to throw at different speeds. The question of how skilled players throw the ball accurately to the desired location under different speed conditions is of interest to biomechanics researchers. Previous research suggested that throwers use different types of joint coordination. However, joint coordination with a change in throwing speed has not been studied. Here, we show the effects of changes in throwing speed on joint coordination during accurate overhead throwing. Participants were seated on a low chair with their trunk fixed and threw a baseball aimed at a target under 2 different speed conditions (slow and fast). In the slow condition, the elbow flexion/extension angle coordinated with other joint angles and angular velocities to reduce the variability of the vertical hand velocity. In the fast condition, the shoulder internal/external rotation angle and the shoulder horizontal flexion/extension angular velocity coordinated with other joint angles and angular velocities to reduce the variability of the vertical hand velocity. These results showed that joint coordination differed with changes in throwing speed, indicating that joint coordination is not always fixed, but may differ depending on the task constraints, such as throwing speed.

Efecto de la edad relativa en la élite del balonmano femenino español y su relación con aspectos antropométricos, de rendimiento y velocidad de lanzamiento / Efeito relativo da idade na élite do andebol feminino espanhol e sua relação com aspectos antropométricos, desempenho e velocidade de arremesso / Relative age effect in Spanish elite of female handball and its relationship with anthropometry, physical performance and throwing speed

El efecto de la edad relativa(RAE)es un aspecto de relevancia en el deporte en general y en balonmano en particular. Ha sido objeto de gran cantidad de estudios centrados mayoritariamente en deporte masculino. Los estudios sobre RAEen balonmano femenino, no son tan numerosos, y no aclaran el efecto de la misma en esta modalidad deportiva. Por ello, el objetivo de este estudio fue determinar la existencia deRAEen jugadoras de élite de balonmano, así como valorar dicho efecto en función de variables antropométricas, de condición física y técnico tácticas (velocidad de lanzamiento). Han sido evaluadas 136 jugadoras de balonmano de los ocho primeros equipos de división de honor. Se ha encontrado un RAE(con la prueba de chi-cuadrado) en las jugadoras de balonmano, sustentado por aquellas que formaron parte de los equipos nacionales. No se apreció RAEen las variables antropométricas, ni en las velocidades de lanzamiento con y sin interacción. La lateralidad y el Squat Jump, presentaron RAE. El RAEes importante para llegar a la selección, pero para jugar en la máxima categoría el efecto de la edad relativa no es tan importante. Son necesarios más estudios sobre el RAEen el balonmano femenino. (AU)

Relative age effect(RAE)is an aspect of relevance in sport in general and in handball in particular. It has been the subject of a great number of studies focused largely on men's sport. RAE studies in female handball are not so numerous, and do not clarify the effect of female handball on this sport. Therefore, the aim of this study was to establish the effect of RAEon élite handball players, as well as to assess this effect based on anthropometric variables, physical fitness and technical and tactical skills (throwing speed). 136 handball players from the first eight honour division teams have been assessed. RAE has been found (with chi-square test) in the handball players supported by those included in national teams. No RAEwere found on anthropometric variables, nor on throwing speed with and without interaction. Laterality and Squat Juam presented RAE. RAEis important to reach the national team, but to play in the highest category the effect of relative age seems to lose weight Further studies on the effect of RAEon women's handball are needed. (AU)

O efeito da idade relativa(RAE)é um aspecto de relevância no desporto em geral e no andebol em particular. Tem sido objeto de elevado número de estudos centrados em grande parte no andebol masculino. Os estudos sobre RAEno andebol feminino, não são tão numerosos, e não clarejam o efeito da mesma nesta modalidade esportiva. Por isso, o objetivo deste estudo foi determinar a existência do RAEem jogadoras de élite de andebol, assim como valorar este efeito em função das variáveis antropométricas, de condição física e técnico-táticas (velocidade de remate). Foram avaliadas 136 jogadoras de andebol das oito primeiras equipas da divisão de honra. Encontrou-se um RAE(foi usado o teste qui-quadrado) nas jogadoras de andebol sustentado pelas que participam nas seleções nacionais. Não se encontrou RAEnas variáveis antropométricas, nem na velocidade de remate com e sem interação. A lateralidade e o Squat Juam apresentaram RAE. O RAEé importante para chegar às seleções, mas para jogar na categoria máxima o RAEparece perder significado. São necessários mais estudos sobre o RAEno andebol feminino. (AU)

Well-Being and Throwing Speed of Women Handball Players Affected by Feedback.

This research aims at studying the effect of feedback on well-being (vitality, and positive and negative affect), competence valuation, perceived competence, motivation, and performance (throwing speed and accuracy) in a throwing task. Thirty nine expert women handball players, with experience in international handball competitions, participated in this study. They were indiscriminately ascribed to one of three different experimental conditions measuring feedback: (positive, negative, and none). Significant differences in well-being (positive affect) and throwing speed were found among the three feedback groups. More concretely, higher levels of positive affect and throwing speed were found in the negative feedback group in comparison with the other two groups (positive and no-feedback). These results have important implications for athletes' well-being and performance, and for coaches' training programs.

Effect of neuromuscular training on functional throwing performance and speed in asymptomatic cricket players.

OBJECTIVE: To determine the effect of neuromuscular training on functional throwing performance and speed among asymptomatic cricket players. DESIGN: Single-subject A-B-A design. METHOD: Forty-three male asymptomatic sub-elite cricket players were recruited from Karnataka Institute of Cricket, Bangalore, India, with a mean age of 20.4 ±â€¯2.03 years. Throwing accuracy and throwing speed were measured using Functional Throwing Performance Index (FTPI) and radar gun respectively, at zero, 12, 24 and 30 weeks in accordance with the A-B-A single-subject design. The neuromuscular training of the throwing arm was performed for 12 weeks, two days a week of supervised training including rhythmic stabilization drills were performed. A non-supervised training session including shoulder strengthening programme was conducted three days a week. RESULT: Participants demonstrated significant improvement in throwing accuracy (p < 0.001) and speed (p < 0.001) after 12 weeks of neuromuscular training. Six weeks post-withdrawal of the neuromuscular training on throwing accuracy was not significant (p = 0.117), However, speed was sustained (p = 0.013). CONCLUSION: Neuromuscular training showed an improved efficiency in throwing performance following 12 weeks of training in sub-elite cricket players. The sustained effect was not observed following 6 weeks of withdrawal of training.

Shoulder rotator muscle dynamometry characteristics: side asymmetry and correlations with ball-throwing speed in adolescent handball players.

THE AIM OF THE INVESTIGATION WAS TO: 1) compare shoulder external/internal rotator muscles' peak torques and average power values and their ratios in the dominant and non-dominant arm; 2) determine correlations between shoulder rotator muscles' peak torques, average power and ball-throwing speed in handball players. Fourteen 14 to 15-year-old male athletes with injury-free shoulders participated in the study (body height: 176 ± 7 cm, body mass 63 ± 9 kg). The tests were carried out by an isokinetic dynamometer system in the shoulder internal and external rotation movements at angular velocities of 60°/s, 90°/s and 240°/s during concentric contractions. The eccentric external- concentric internal rotator muscle contractions were performed at the velocity of 90°/s. The player threw a ball at maximal speed keeping both feet on the floor. The speed was recorded with reflected light rays. Training in handball does not cause significant side asymmetry in shoulder external/internal rotator muscle peak torques or the average power ratio. Positive correlations between isokinetic characteristics of the shoulder internal and external rotator muscles and ball-throwing speed were determined. The power produced by internal rotator muscles during concentric contractions after eccentric contractions of external rotator muscles was significantly greater in the dominant than in the non-dominant arm. Thus, it may be concluded that the shoulder eccentric external/concentric internal rotator muscle power ratio is significantly greater than this ratio in the concentric contractions of these muscles.