The purpose of this study was to gain an insight into the physical and physiological profile of elite Belgian soccer players with specific regard to the player's position on the field. The sample consisted of 289 adult players from 6 different first division teams. The players were divided into 5 subgroups (goalkeepers, center backs, full backs, midfielders, and strikers) according to their self-reported best position on the field. The subjects performed anaerobic (10-m sprint, 5 × 10-m shuttle run [SR], squat jump [SJ], and countermovement jump [CMJ]) and aerobic (incremental running protocol) laboratory tests. The strikers had significantly shorter sprinting times (5-, 5- to 10-m time, and SR) compared with the midfielders, center backs, and goalkeepers, whereas the full backs were also significantly faster compared with the goalkeepers and the center backs. The goalkeepers and the center backs displayed higher jumping heights (total mean SJ = 40.7 ± 4.6 cm and CMJ = 43.1 ± 4.9 cm) compared with the other 3 positions, whereas the strikers also jumped higher than the full backs and the midfielders did. Regarding the aerobic performance, both full backs and the midfielders (61.2 ± 2.7 and 60.4 ± 2.8 ml · min(-1) · kg(-1), respectively) had a higher VO2max compared with the strikers, center backs, and goalkeepers (56.8 ± 3.1, 55.6 ± 3.5, and 52.1 ± 5.0 ml · min(-1) · kg(-1), respectively). From this study, it could be concluded that players in different positions have different physiological characteristics. The results of this study might provide useful insights for individualized conditional training programs for soccer players. Aside from the predominant technical and tactical skills, a physical profile that is well adjusted to the position on the field might enhance game performance.
The reproducibility of an electronic device for the assessment of periodontal tissues damping characteristics was judged by evaluating the inter-examiner, inter-device and day to day variations of the measurements (PTVs). Nine young periodontally healthy volunteers were examined by two examiners (EX-1 and EX-2) and two devices (D-1 and D-2) in the following sequence: EX-1 D-1, EX-2 D-1, EX-1 D-2, and EX-2 D-2. PTVs were obtained at 5 different occasions during the same day. In some instances examiner 2 measured higher scores than examiner 1 with both devices. This difference was statistically significant (P = 0.05), if the total of 900 measurements was considered. The measurements of device 2 were approximately 0.5 PTV units higher, also reaching a statistical significance (P = 0.05). This difference is of limited clinical significance. The day to day variation was evaluated by comparing the scores obtained at 8 a.m. with the ones at the four other periods. The lowest scores were measured at 8 a.m. Only the 11 a.m. and the 2 p.m. measurements differed significantly. The effect of hormonal changes during the menstrual cycle and of smoking habits on PTVs were also evaluated. Ten female periodontally healthy volunteers were examined three times a week, during a period of two menstrual cycles. No significant PTV changes were found during the menstrual cycle. The effect of the smoking habit on PTVs was tested on 23 periodontally healthy patients.(ABSTRACT TRUNCATED AT 250 WORDS)
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.