Research in Sport Medicine and Technology

Various studies have shown that the external focus of attention is better than the internal focus of attention. But, so far no study has been investigated the level of electrical activity of the rectus abdominus muscle as a trunk stabilizer muscle. Therefore, the purpose of this study was to investigate the effect of focus of attention on electromyography activity of the rectus abdominus muscle during Different phases of vertical jump.Twelve male elite volleyball players from university of Tehran Participated in this research voluntary. They performed a vertical jump on the force plate in both internal and external focus of attention condition. Rectus abdominus Surface electromyography (SEMG) signals recorded by electromyography apparatus during vertical jump and The electrical activity of this muscle was calculated in the different phases of vertical jump motion.  Paired t-test results showed that height of jump under the external focus was higher than the internal focus. In addition, this  results showed that internal focus caused significant increasing in Rectus abdominus EMG in comparison to external focus during concentric phase. But, there was no significant difference in the eccentric phase between the external and internal focus of attention conditions. These results suggest that the external focus of attention effectively increases the efficiency of vertical jump. Therefor; we recommend using the external focus of attention instructions when executing vertical jump movement.


 

Feedback instruction is a proven modality for the alteration of motion patterns. There are no existing data on the contribution of strength training, when combined with feedback instruction, to the altering of lower extremity biomechanics. Thus the purpose of the current study was comparison of strength training  program with external and internal focus of attention strategies on kinetic and functional factors in athletes with plyometric pattern. 36 athlete females (handball, Basketball and vollyball) voluntarily with avarage age 22.3±2.27 years were randomly assigned to strength training with external focus, strength training with internal focus and strength training groups. Participants completed these training for 8 weeks. Kinetic factors were measured using force plate during landing, as well as functional movement and movement pattern respectively were measured by single leg triple hop test (SLTH) and landing error scoring system. One-way analysis of variance (ANOVA) showed that the effect of strength training with external focus group training significantly was better than two others groups in Peak vertical ground reaction  (p=0.039), posterior ground reaction force (p=0.046), mediolateral time to stability (p=0.032), single leg triple hop test (p=0.041) and landing error scoring system  scores (p=0.030). But there was no significant between-group difference in anteroposterior time to stability (p=0.312). Subjects in strength training with external focus group showed significantly within-group changes in all variables except anteroposterior time to stability from posttest to pretest. Programs that include both strength training and movement education through external focus of attention may be necessary in order to prevent ACL injuries and increase athletic performance.