title: [Effects of Reactive Jump Training in Handball Players Regarding Jump Height and Power Development in the Triceps Surae Muscle].
abstract: BACKGROUND
  Studies have shown changes in the technical and physical demands in modern handball. The game has increased considerably in speed, power and dynamics. Jump training has, therefore, become ever more important in the training of the athletes. These developments contribute to the fact that handball is now one of the most injury-prone types of sport, with the lower extremities being most frequently affected. Reactive jump training is not only used in training by now, but also increasingly in injury prevention. The aim of this study was to investigate the effectiveness of reactive jump training with handball players.
  
  
  METHODS
  21 regional league handball players were randomly divided into an intervention group (n = 12) and a control group (n = 9). The intervention group completed a six-week reactive jump training programme while the control group went through a non-specific training programme. Jump height (squat and counter movement jump), isokinetic and isometric maximum power as well as muscle activity served as measuring parameters.
  
  
  RESULTS
  A comparison of the intervention and control groups revealed that the reactive jump training led to significant improvements in jump height. The isometric and isokinetic maximum power measurements and the electromyographic activities of the triceps surae muscle demonstrated an improvement in the values within the intervention group. However, this improvement was not significant compared with the control group. Likewise both jumps correlated with the muscle activity of the soleus muscle as shown by electromyography. A moderate correlation was noticed between the isokinetic maximum power measurement and the electromyographic activity of the soleus and gastrocnemius medialis muscles. Furthermore, the correlations of the isometric and isokinetic maximum power meas-urements resulted in a strong correlation coefficient.
  
  
  CONCLUSIONS
  This study revealed a significant increase in jump height after reactive jump training. There was no significant difference in power development between the two groups. However, we were able to demonstrate correlations which would make it seem reasonable and interesting to investigate the question more closely. An interesting field of research could be the question of the effectiveness of reactive jump training in the areas of rehabilitation and injury prevention.
authors.forename: N
authors.initials: N
authors.lastname: Rensing
authors.forename: A
authors.initials: A
authors.lastname: Westermann
authors.forename: D
authors.initials: D
authors.lastname: Möller
authors.forename: H
authors.initials: H
authors.lastname: von Piekartz
mesh_terms: D000328:Adult; D054874:Athletic Performance / Q000502:physiology*; D006801:Humans; D008297:Male; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D064797:Physical Conditioning, Human / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013177:Sports / Q000502:physiology*; D016896:Treatment Outcome; D055815:Young Adult