Article Critique
Article Questions: According to the article, no study had been done like this before. There had been tests studies on overall agility, but they were almost always associated with injury mechanics instead of how agility can be used to find an athletes optimal performance level. The subjects for the study were 29 volleyball players from various NCAA divisions (nine from Division I, eleven from Division II, and nine from Division III). All of the athletes were had experienced similar drills. The first variable that was measured was the time for toe off to heel down for the agility test . For this test they used a platform that measured force (AMTI platform). A second variable that was tested was CM height in the vertical jump test. A vertec device was the instrument used to measure the jump and reach height of both the CM jump and the DJ jump.
Authors’ purpose statement (word-for-word from the text) and purpose statement in your own words:
“Therefore the purpose of this investigation was to describe jumping and agility performance in female collegiate volleyball players, distinguish between the vertical and horizontal forces during a COD movement, and correlate agility performance with the force-time variables from the vertical jump and isometric leg extensor performance.” The purpose of this study was to find out if the force of a COD movement in both vertical jumps and isometric leg extensor actions correlated with overall quality of agility performance.
Methodology:
All of the participants in this study were collegiate volleyball players. Nine of the athletes were from Division I schools, eleven were from Division II schools, and the final nine were from Division III schools. All of the subjects had been part of similar training programs and had had medical/physical questionnaires completed before they began testing. Each subject participated in three different sections of the study: vertical jump, agility, and isometric leg extensor. Practice as allowed during the first visit for the subjects. The best trial for the next two attempts was recorded for later analysis. Each player was required to wear the same a footwear each day and each trial was separated by at least three days. The first test was the agility test. A multidimensional force platform was used to collect force-time data. For this test, the subjects began with their right foot on the platform and then (after they were told to do so) would plant the left foot and run five meters and then turn 180 degrees to the right and then spring back to the first platform. After this they would plant their right foot on the platform turn to the left and change directions. They would finish by running back 5 meters over the force platform with one foot. A vertec device as used to measure jump and reach height of the participants. The height of the drop box stayed the same for every volleyball player. Reactive strength index and contact time were also measured on this test. For the isometric leg extensor action test, subjects were positioned on a vertical only force platform that placed their shoulders under a fixed bar and the knees at 120 degrees. The subjects would get on the platform and push as hard as they could for 2.5-4 seconds. The force was measured from the platform that was below them. Their best attempt was used for statistical analysis
Results:
The article states that there were really no major differences from any of the tests from one division to the others. The only result that had a major discrepancy was the Countermovement Jump Height (CMHT) from Division I to Division 3. Table 2 shows that the nine contestants of Division I had 36.4 centimeters while Division III had 30.2 centimeters. From looking at the results at in Table 2, all of the other things that were measured seem to line up very closely. Three of the standard deviations are less that one, which is usually what is your aiming point in a study. Some of the other variables have higher standard deviation such as PF but that is because the mean is such a larger number than some of the other variables such as CT.
Discussion and Critique:
The authors of this article declared that their major finding for this study was that countermovement jump height can be used to help predict the test time for agility. They also found that the vertical domain is a limiting factor in the COD task. In the discussion section, the authors hit on something that I was thinking of the entire time I was reading this study: of course there will be high results in the jumping section of this study because it was based around volleyball players. Volleyball players are required to jump higher than athletes in almost every other sport. I think that this study could have been opened up to athletes from other sports so that the results could be measured and compared from sport to sport. If these findings are true for other sports, they can be used in the field that I’m going into (coaching). Coaches can use this study as a reference when trying to recruit players to come play at a Division II or Division III school because they can show them that the level of agility between player across the divisions is not as different. Some players might be apprehensive to go to a lower division because they do not think that they are as competitive as a Division I conference.