title: Effects of shock-absorbing insoles during transition from natural grass to artificial turf in young soccer players: a randomized controlled trial.
abstract: BACKGROUND
  Playing soccer on artificial turf can provoke pain in young players. Using shock-absorbing insoles (SAIs) can result in decreased pain perception. We sought to investigate the pain and comfort intensity experienced during the switch from natural grass to third-generation artificial turf and with the use of SAIs on artificial turf during training in young soccer players.
  
  
  METHODS
  In a prospective randomized controlled study, 75 players were included from the youth teams of U15, U17, and U19. Pain intensity and comfort were assessed after training on only grass turf for 3 months. Randomization stratified by team level and age was performed; the intervention group received SAIs, and the control group used their own insoles. Assessments were repeated after 3 weeks on artificial turf (baseline) and 3 more weeks (follow-up) on artificial turf with SAIs/usual insoles.
  
  
  RESULTS
  Pain intensity increased and comfort decreased significantly after 3 weeks of training on artificial grass compared with natural grass (P < .05). The addition of SAIs resulted in significantly reduced pain intensity compared with the usual insoles (P < .05).
  
  
  CONCLUSIONS
  The switch to artificial turf is associated with less comfort and more pain during training in young soccer players. The use of SAIs led to lower pain intensity, highlighting a protective role of the insoles after 6 weeks of training on artificial turf.
authors.forename: Søren
authors.initials: S
authors.lastname: Kaalund
authors.forename: Pascal
authors.initials: P
authors.lastname: Madeleine
mesh_terms: D000293:Adolescent; D061826:Foot Orthoses; D006801:Humans; D010146:Pain / Q000517:prevention & control*; D010147:Pain Measurement; D006109:Poaceae; D011446:Prospective Studies; D012775:Shoes; D012916:Soccer