The purpose of this study is to observe the jump height from preparatory to match periods and investigate the effect of changes in physical activity volume on jumping performance in female collegiate volleyball players. The sample data of thirty-four players (Age: 19.1±1.0, Height: 168.0±5.9cm, Weight: 63.2±6.2kg) was obtained from the KANTO divisionIwomen collegiate volleyball league in the 2018 autumn and 2019 spring and autumn periods. The physical activity was recorded daily during volleyball training using Active Style Pro HJA-750c (OMRON co.). Other than the measurements of body composition, counter-movement jump (CMJ) and CMJ with arm swing (CMJ-AS) were completed by preparation (Pre and Post1) and match periods (Post2 and Post3). Furthermore, the sample data was classified as decrease and maintain groups based on the ratio of changes in jump height from Pre to Post1. The results revealed that physical activity was highest in Post1 and decreased by approximately 50% in Post2. The jump height was considerably lower in Post1 than in Pre but remarkably higher in Post2. In the comparison between the decrease and maintain groups, the physical activity volume of Post1 was more common in the decrease group than in the maintain group. These findings revealed that the jumping performance of female collegiate volleyball players is influenced by the increases and decreases of physical activity volume during volleyball training.

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The purpose of this study is to clarify specific movement methods for adjusting the timing. It is used the timing practice of spikes of volleyball as a condition of the trials. Subjects take off from one stepping approach for a hand-thrown toss and catching the ball with both hands in the air while adjusting the timing. The main results are as follows: 1)For adjusting the timing, it was found necessary to use some movement as a preparatory action to obtain the appropriate movement start. 2)The forward tilt and the rocking movement of the trunk and relaxed arms or hands lead to adjusting the timing on a higher toss. 3)The stepping forward and pulling movements of the foot, short stepping, and knee flexion were critical to increasing the number of successes in adjusting the timing task regardless of the height of the toss. 4)From the results of 2) and 3), it was found that there were different phases to increase the number of successes in adjusting the timing task on a high toss. The first was the base phase of movement centered on the trunk. The second was an application phase of movement centered on the foot.

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The purpose of this study was to examine the effects of offensive tactics taken against overpass from the receiving side of the court through the analysis of V1 Men’s League games, and discover possibilities for coaching in practice. This technique has been used recently in top-level men's volleyball games. The following are the results of the analysis. 1. The kill percentage on direct attacks made when the opposing team’s setter was the back row was 70%, significantly higher than the 49% found when the setter was the front row (p<.05). 2. 0% of direct attacks were blocked when the opposing setter was in the front row, significantly lower than that of the 12% blocked percentage of free ball attacks. The 3% of losing points from direct attacks was also significantly lower than that free ball attacks, which was 19% (p<.05). Direct attacks had significant trend toward higher, with a 49% attack efficiency, compared to 30% during free ball attacks (p<.10). 3. 2% of direct attacks were blocked when the opponent's setter was the back row, significantly lower than the percentage of free ball attacks, which were blocked 13% of the time (p<.05). 65% of direct attack efficiency, significantly trend toward higher than the 47% efficiency of free ball attacks (p<.10). 4. The results of the analysis on the number of participants involved in blocking showed a significant difference in the results in direct attacks from opponents setter in the front row and back row (p<.001). 5. The results of the analysis on the number of participants involved in blocking showed a significant difference in the results in direct and free ball attacks (p<.001). From the above, it can be concluded that, for overpass from the receiving side of the court in top level men’s play, when the setter of the opposing team is in the back row, the opposition will often have no way to block direct attacks, proactively making direct attacks is highly effective, as is done in current offensive strategies. Also as seen in recent offensive strategies, there is a possibility that, when the opposing setter is in the front row, it is better to attempt a direct attack while remaining cautious of block made by the opposing setter on their own, than it is to handle overpass as free balls and making a free ball attack.

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The purpose of this study was to examine the changes in acromiohumeral distance (AHD), range of motion (ROM) of the shoulder joint, and scapular alignment caused by repeated spike motion. 10 collegiate male volleyball players who participated in this study. Spike motion repeated 50 times. AHD, internal rotation and horizontal flexion in shoulder joint and scapular alignment were measured before and after the volleyball spike task. There was no significant difference of AHD between before and after the task. However, after the task, the 2nd internal rotation and horizontal flexion range of the shoulder joint significantly decreased on the dominant compared to the non-dominant. Also, after the task, the scapula significantly showed upward rotation at 45° abduction and depression at neutral position in shoulder joint. It was suggested that 50 repetitions of the spike motion may cause posterior shoulder tightness (PST) and altered scapula alignment, but it did not decrease AHD. The results of this study were immediate changes after 50 repetitions of the spike motion, so it is necessary to examine the changes over time in the future.

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The objective of this study was to obtain information for future volleyball coaching by analyzing the associations among patterns of slide attacks after reception (serve receiving), results of attacks, and outcomes of matches. The data were collected from 168 sets in a total of 45 matches, consisting of those in the third round of 8-team round-robin 3-match regular rounds and those in the final round participated in by the top 6 teams in regular rounds in the 2015-16 Women’s V Premier League. The following were the main results: 1) The pattern of slide attacks clearly differed between the times when the ball was fed to the setter in their home position by the reception (A pass) and the times when the setter moved to receive the pass (B pass). Attacks from straight behind the setter (SA) were observed more frequently after A passes, and those from positions near the antenna (SC) were observed more frequently after B passes. 2) In slide attacks after receptions, the percentage of hard driven spikes after B passes was higher for the winner than for the looser of the set. 3) The results of slide attacks after receptions, particularly the results of attacks after A passes, were associated with the outcomes of matches. 4) Of the slide attacks after receptions, the results of those from near the antenna (SC) were more closely associated with the outcomes of matches. 5) In slide attacks after receptions, the results of both hard driven spikes and soft attacks were associated, but those of hard driven spikes were more closely associated with the outcomes of the sets.

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