Wrist flexors are steadier than extensors.

To examine torque variability in 2 antagonistic muscles 20 individuals performed maximal and submaximal (5, 10, 20, 50 and 75% of Maximal Voluntary Contraction, MVC) isometric wrist flexions and extensions (5 s) at 5 different angles (230, 210, 180, 150 and 130°). The EMG activity of Flexor Carpi Ulnaris (FCU) and Extensor Digitorum (ED) was recorded and quantified as the integral of EMG. Participants showed higher maximal isometric torque (32.43±11.17 vs. 17.41±3.84 Nm) and lower coefficient of variability during wrist flexion compared to extension. The normalized agonist EMG increased across higher levels of torque for both wrist muscles. Interestingly, the coactivation of ED during wrist flexion was greater compared to the coactivation of FCU during wrist extension at 50 and 75% of MVC, regardless of wrist angle (f.e.: at 180° and 75% of MVC the normalised EMG of ED as antagonist was 14.84±5.18% vs. 9.33±6.94 of the FCU). It is concluded that a stronger isometric wrist flexion is more steadily produced, with greater coactivation compared to a weaker wrist extension, independently from muscle length and torque level. Even if the relative contribution of antagonists to the resultant torque is to be considered, altered activation patterns responsible for differences in force fluctuations could be suggested.

Velocity, agility, and flexibility performance after handball training versus physical education program for preadolescent children.

The performance on velocity, agility, and flexibility after six months of specific handball training or a mainstream physical education program was examined in participants (handball, n = 51; physical education, n = 70) who engaged in 3 sessions per week (60 min./sesson) including ball-handling exercises, horizontal and vertical jump shots, fast breaks, and several defensive skills. Statistically significant differences were observed between the two groups on velocity, agility, and flexibility with differences favouring the handball group. Handball training could significantly improve preadolescents' physical performance.