Introduction Gymnastics is characterized by closed skills motor tasks that require consistent movement patterns with minimal variations. As movement variability decreases with practice (Shumway-Cook and Woollacott, 2007), repeated practice is largely used by gymnasts to obtain movement consistency. The hypothesis for this study was that movement variability decreases as level of expertise increases. Thus, the purpose was to compare intra-individual biomechanical variability in the execution of the back handspring on the floor between two female gymnasts at different competition levels. Methods.Two female gymnasts volunteered in the study.The gymnasts competed respectively in pre-junior (L2) and junior (C2) categories.Kinetics data from a Kistler force platform (1000 Hz) of the dominant hand were collected during six trials of back handsprings for each gymnast. The hand contact time, average vertical force, impact peak, time to impact peak and impulse were compared between the gymnasts by using the Mann Whitney test. Intra-individual variability was calculated by using %RMSD. Results Average vertical force and impact peak resulted to be significantly different between the gymnasts. The intra-individual variability recorded were 13%L2 and 6%C2 for the hand contact time, 7%C2 and 2%L2 for average vertical force, 12%C2 and 5%L2 for impact peak, 18%C2 and 25%L2 for time to impact peak and 19%C2 and 5%L2 for the impulse. Discussion Lack of significant differences in temporal variables showed that coordination level was not improved at a higher level of expertise. Similar findings were obtained by a previous study focus on variability among baseball pitchers (Fleising et al, 2009). On the contrary, the significant differences found in kinetics measurers in this study contrasted with the results reported by Fleising et al (2009). The significant difference in the impact peak could represent an increased risk of injuries for the pre-junior gymnast. The pre-junior gymnast had a greater intra-individual variability in all the variables in comparison to the junior gymnast with the exception of the time to impact peak. The variability that characterized the pre-junior gymnast`s performance was a random variability caused by a reduced ability to control the task. The variability showed by the junior gymnast was a functional variability that represented a personal strategy used to complete the motor task(Barlett et al 2007). A better understanding of the biomechanical intra-variability associated with different level of expertise in closed skills sport can effectively contribute to accelerate the learning process and reduce the risk of injuries. References Bartlett R, Wheat J, Robins M.(2007). Sports Biom 6 (2), 224-243. Shumway-Cook A, Woollacott MH (2007). Fleising G, Chu Y. Weber A, Andrews J. (2009) Sports Biom 8(1) 10-21.

Intraindividual biomechanical variability in backhandspring in different levels of expertise

PENITENTE, GABRIELLA;MERNI, FRANCO
2011

Abstract

Introduction Gymnastics is characterized by closed skills motor tasks that require consistent movement patterns with minimal variations. As movement variability decreases with practice (Shumway-Cook and Woollacott, 2007), repeated practice is largely used by gymnasts to obtain movement consistency. The hypothesis for this study was that movement variability decreases as level of expertise increases. Thus, the purpose was to compare intra-individual biomechanical variability in the execution of the back handspring on the floor between two female gymnasts at different competition levels. Methods.Two female gymnasts volunteered in the study.The gymnasts competed respectively in pre-junior (L2) and junior (C2) categories.Kinetics data from a Kistler force platform (1000 Hz) of the dominant hand were collected during six trials of back handsprings for each gymnast. The hand contact time, average vertical force, impact peak, time to impact peak and impulse were compared between the gymnasts by using the Mann Whitney test. Intra-individual variability was calculated by using %RMSD. Results Average vertical force and impact peak resulted to be significantly different between the gymnasts. The intra-individual variability recorded were 13%L2 and 6%C2 for the hand contact time, 7%C2 and 2%L2 for average vertical force, 12%C2 and 5%L2 for impact peak, 18%C2 and 25%L2 for time to impact peak and 19%C2 and 5%L2 for the impulse. Discussion Lack of significant differences in temporal variables showed that coordination level was not improved at a higher level of expertise. Similar findings were obtained by a previous study focus on variability among baseball pitchers (Fleising et al, 2009). On the contrary, the significant differences found in kinetics measurers in this study contrasted with the results reported by Fleising et al (2009). The significant difference in the impact peak could represent an increased risk of injuries for the pre-junior gymnast. The pre-junior gymnast had a greater intra-individual variability in all the variables in comparison to the junior gymnast with the exception of the time to impact peak. The variability that characterized the pre-junior gymnast`s performance was a random variability caused by a reduced ability to control the task. The variability showed by the junior gymnast was a functional variability that represented a personal strategy used to complete the motor task(Barlett et al 2007). A better understanding of the biomechanical intra-variability associated with different level of expertise in closed skills sport can effectively contribute to accelerate the learning process and reduce the risk of injuries. References Bartlett R, Wheat J, Robins M.(2007). Sports Biom 6 (2), 224-243. Shumway-Cook A, Woollacott MH (2007). Fleising G, Chu Y. Weber A, Andrews J. (2009) Sports Biom 8(1) 10-21.
Book of Abstracts of the 16th Annual Congress of the European College of Sport Science, 6-9 July 2011, Liverpool - United Kingdoma
234
234
Penitente G.; Thomas L.S.; Merni F.
File in questo prodotto:
Eventuali allegati, non sono esposti

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11585/103302
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? ND
social impact