The purposes of this study were to investigate sprints and to characterize repeated-sprint sequences (RS) performed by athletes during professional futsal matches. We analyzed 97 players during 5 official matches using the DVideo automatic tracking system. The sprints were analyzed during the first and second halves according to playing position, and RS were categorized according to the number of sprints and the time between them. The results showed an increase (F[1, 2520] = 3.96; P = .046) in the sprint duration from the first (mean = 3.1 ± 1.3) to the second half (mean = 3.2 ± 1.2). However, no differences were found for other variables (distance covered, peak velocity, initial velocity, recovery time between sprints, and sprints performed per minute) or among playing positions. In addition, when considering RS, the results showed that RS comprising two sprints interspersed with a maximum of 15 seconds of recovery were significantly more frequent than other RS. The findings of this study characterizing the sprinting features of futsal players can help coaches to plan physical training and assessments according to the requirements of the sport.
Fabio Giuliano Caetano, Murilo José de Oliveira, Ana Lorena Marche, Fábio Yuzo Nakamura, Sergio Augusto Cunha and Felipe Arruda Moura
Stephen J. Pearson, Tim Ritchings and Ahmad S.A. Mohamed
The work describes an automated method of tracking dynamic ultrasound images using a normalized cross-correlation algorithm, applied to the patellar and gastrocnemius tendon. Displacement was examined during active and passive tendon excursions using B-mode ultrasonography. In the passive test where two regions of interest (2-ROI) were tracked, the automated tracking algorithm showed insignificant deviations from relative zero displacement for the knee (0.01 ± 0.04 mm) and ankle (–0.02 ± 0.04 mm) (P > .05). Similarly, when tracking 1-ROI the passive tests showed no significant differences (P > .05) between automatic and manual methods, 7.50 ± 0.60 vs 7.66 ± 0.63 mm for the patellar and 11.28 ± 1.36 vs 11.17 ± 1.35 mm for the gastrocnemius tests. The active tests gave no significant differences (P > .05) between automatic and manual methods with differences of 0.29 ± 0.04 mm for the patellar and 0.26 ± 0.01 mm for the gastrocnemius. This study showed that automatic tracking of in vivo displacement of tendon during dynamic excursion under load is possible and valid when compared with the standardized method. This approach will save time during analysis and enable discrete areas of the tendon to be examined.
Seyed Mohsen Hosseini, Mojtaba Azizi, Ali Samadi, Nahid Talebi, Hannes Gatterer and Martin Burtscher
RP , et al . Analysis of the distances covered by first division Brazilian soccer players obtained with an automatic tracking method . J Sports Sci Med . 2007 ; 6 ( 2 ): 233 – 42 . PubMed 24149334 4. Berent R , von Duvillard SP , Crouse SF , et al . Short-term residential cardiac
Gabriel Motta Pinheiro Brisola, Elvis de Souza Malta, Paulo Roberto Pereira Santiago, Luiz Henrique Palucci Vieira and Alessandro Moura Zagatto
– 11 . doi:10.1080/21681163.2015.1072055 16. Barros RML , Misuta MS , Menezes RP , et al . Analysis of the distances covered by first division Brazilian soccer players obtained with an automatic tracking method . J Sport Sci Med . 2007 ; 6 ( 2 ): 233 – 242 . PubMed ID: 24149334 17. Hill
Mário A.M. Simim, Gustavo R. da Mota, Moacir Marocolo, Bruno V.C. da Silva, Marco Túlio de Mello and Paul S. Bradley
-1375695 10.1055/s-0034-1375695 Barros , R.M.L. , Misuta , M.S. , Menezes , R.P. , Figueroa , P.J. , Moura , F.A. , Cunha , S.A. , … Leite , N.J. ( 2007 ). Analysis of the distances covered by first division Brazilian soccer players obtained with an automatic tracking method . Journal of