The aim of this study was to examine the effects of different agility training methods on skill-related physical capabilities in young volleyball players. Twenty-seven young female volleyball players were randomly assigned to a shuttle-run training group (STG, n = 9), an agility-ladder training group (ATG, n = 9), and a control group (CG, n = 9). The intervention program was carried out three times a week for six weeks. Before and after the training period, participants’ 10 m sprint (10 MS), agility T-test, and digging agility test (DAT) performances were assessed. Within-group analysis showed significant improvements (p < 0.05) in the DAT, agility T-test, and 10 MS performance from pre- to post-test for the STG (6.08%, 2.64%, and 5.68%, respectively) and ATG (4.05%, 3.28%, and 3.27%, respectively). In the group analysis, there were significant differences (p < 0.05) between the STG and CG in the DAT and agility T-test. The STG and ATG were significantly superior to the CG in the 10 MS (p < 0.05). In conclusion, the results indicate that appropriate agility training can enhance the agility of lateral movements and speed of sprinting, as well as enable players to rapidly complete movements during a moving defense.

Backpacks are commonly worn by many people for multiple purposes. This study investigated the effects of habitual wearing of backpacks on lower limb kinematics and kinetics. Fourteen participants were recruited for analysis. All participants performed four randomly assigned scenarios, including running and walking at speeds of 3.5 and 1.5m/s, respectively, with and without load carriage. The motion analysis system and force plate were used to investigate the lower limb kinematics and kinetics. A paired sample t-test was performed for statistical measurement with a significance level of α.05. The results indicated that active force, breaking force, impact peak, loading rate, active peak, maximum braking, hip flexion, and hip range of motion were substantially higher under load carriage conditions than under walking condition, however, time to peak was lower. Conversely, during load carriage running, active force, braking impulse, time to peak, ankle plantarflexion, and ankle range of motion were all higher than those during running. Carrying a backpack weighing 10 of the body weight induced different foot strike patterns at both speeds; during load carriage walking, the hip tended to flex more; whereas, during load carriage running, the ankle tended to flex more. In conclusion, human body seems to adopt different gait strategies during load carriage walking and running. That is, the hip strategy is used during walking, while the ankle strategy is used during running.

Ferredoxin is an iron-sulfur protein that serves as an electron transport intermediate for mitochondrial cytochromes P450 involved in steroid, vitamin D, and bile acid metabolism. We cloned and characterized the human ferredoxin gene family, which includes two expressed genes and two pseudogenes. Sequence analysis of this gene family revealed that it encodes only one protein product. The expressed genes were assigned to chromosome 11 and pseudogenes to chromosomes 20 and 21 by identifying single-copy probes from each gene segment and hybridizing them to DNA from rodent-human hybrid cells. The pseudogenes lacked introns and contained numerous mutations, including insertion, deletion, and substitution which rendered them inactive. They were 96% and 85% homologous to the expressed gene, yet they were only 78% homologous with each other. The intronless nature, higher diversity among themselves, and distinct chromosomal location of the pseudogenes suggests that they arose by independent, retroposon-mediated events.

In volleyball matches, there are three minute intervals between sets. Therefore, the improvement of the muscle output ratio is one of the most import foundational physical elements for the players. The purpose of this study was to investigate the effects of plyometric training on the changes in electrical signals in the lower limb muscles of male college volleyball players during continuous blocking and to examine the benefits of plyometric training on blocking agility and maximum vertical jump height. In this study, twenty elite male college volleyball players were recruited and divided into a plyometric training group (PTG) and a control group (CG). The wireless electromyography was used for data acquisition, and the electrodes were applied to the left and right rectus femoris, biceps femoris, tibialis anterior, and gastrocnemius. The median frequency was used as the measurement of the electromyographic signals during the jumping blocks. This study used covariate analysis methods, with previously measured results used as covariates to perform a two-way analysis of covariance for the independent samples. Based on the results of this study, after 6 weeks of training, the median frequency of the rectus femoris (2.13% to 4.75% improved) and that of the tibialis anterior muscles (4.14% to 7.71% improved) were significantly lower in the PTG than in the CG. Additionally, the blocking agility increased by 6.26% and the maximum vertical jump height increased by 3.33% in the PTG compared to the CG. The findings provide important insights on the neuromuscular status for volleyball players during continuous blocking jumps. Six weeks of appropriate plyometric training can facilitate the performance of volleyball players.

The purpose of this research was to study the effects of complex functional strength training (whole-body vibration + unstable surface training) on overall shooting performance, including the shooters’ stability of hold, time on target, and the body sway. We compared the shooters’ performances at three time intervals: (a) pretraining, (b) 6 weeks post-WBV+UST, and (c) 6 weeks detraining. The study participants were eight rifle shooters. Training was c on an unstable surface with vibration frequency of 30 Hz and amplitude of 2 mm. Six weeks after complex training, participants’ shooting performance and body sway significantly improved. Specifically, shooting scores and total time improved by 5.50% and 7.34%, respectively, as did the DevTotal values between performances at different times: 10 ms (p = 0.01), 20 ms (p = 0.04), 30 ms (p = 0.02), and 40 ms (p = 0.02). The DevY values also showed significant differences between performances at different times: 10 ms (p < 0.01), 20 ms (p < 0.01), 30 ms (p < 0.01), 40 ms (p < 0.01), and 50 ms (p < 0.01). A 6 week complex training method can effectively improve shooting stability, fluency, and scores.