title: Time-dependent postural control adaptations following a neuromuscular warm-up in female handball players: a randomized controlled trial.
abstract: BACKGROUND
  Female handball athletes are at a particular risk of sustaining lower extremity injuries. The study examines time-dependent adaptations of static and dynamic balance as potential injury risk factors to a specific warm-up program focusing on neuromuscular control.
  
  
  METHODS
  Fourty one (24.0 ± 5.9 years) female handball athletes were randomized to an intervention or control group. The intervention group implemented a 15-min specific neuromuscular warm-up program, three times per week for eleven weeks, whereas the control group continued with their regular warm-up. Balance was assessed at five time points. Measures included the star excursion balance test (SEBT), and center of pressure (COP) sway velocity during single-leg standing.
  
  
  RESULTS
  No baseline differences existed between groups in demographic data. Adherence to neuromuscular warm-up was 88.7 %. Mean COP sway velocity decreased significantly over time in the intervention group (-14.4 %;p< .001), but not in the control group (-6.2 %;p= 0.056). However, these effects did not differ significantly between groups (p= .098). Mean changes over time in the SEBT score were significantly greater (p= .014) in the intervention group (+5.48) compared to the control group (+3.45). Paired t-tests revealed that the first significant balance improvements were observed after 6 weeks of training.
  
  
  CONCLUSIONS
  A neuromuscular warm-up positively influences balance variables associated with an increased risk of lower extremity injuries in female handball athletes. The course of adaptations suggests that a training volume of 15 min, three times weekly over at least six weeks produces measurable changes.
  
  
  BACKGROUND
  Retrospectively registered on 4th October 2016. Registry: clinicaltrials.gov. Trial number: NCT02925377.
authors.affiliation: Institute of Sport Science and Sport, Division of Exercise and Health, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany.
authors.forename: Simon
authors.identifier: 0000-0002-5767-8205
authors.initials: S
authors.lastname: Steib
authors.affiliation: Institute of Sport Science and Sport, Division of Exercise and Health, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Zahn
authors.affiliation: University Medical Center Groningen, Faculty of Medical Sciences, University of Groningen, Groningen, Netherlands.
authors.forename: Christine
authors.initials: C
authors.lastname: Zu Eulenburg
authors.affiliation: Institute of Sport Science and Sport, Division of Exercise and Health, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany.
authors.forename: Klaus
authors.initials: K
authors.lastname: Pfeifer
authors.affiliation: Department of Sport Science, Friedrich Schiller University Jena, Jena, Germany.
authors.forename: Astrid
authors.initials: A
authors.lastname: Zech
keywords: Balance; Injury prevention; Neuromuscular training; Postural control; Sensorimotor training