title: Risk factors for developing jumper's knee in sport and occupation: a review.
abstract: BACKGROUND
  The onset of jumper's knee is generally associated with sports and sporting activities. Employees in certain professions might be at risk as well for developing jumper's knee. Therefore, it is of interest to identify risk factors in sport and/or occupation.
  
  
  RESULTS
  A systematic search of the international scientific literature was performed until November 2008 in the scientific databases (a) Medline, (b) Embase, and (c) SportDiscus. All types of studies were included. The search strategy retrieved ten articles about risk factors in sport that met the inclusion criteria. Risk factors that could be identified are; playing volleyball (4 studies), playing basketball (3 studies), training and playing volleyball/basketball more than 12 hours per week (2 studies), in combination with weight-bearing activities of at least 5 hours per week (1 study) and playing or training on a hard surface (1 study). No studies were found regarding occupation that fulfilled the inclusion criteria.
  
  
  CONCLUSIONS
  Playing volleyball and basketball has a positive association with the onset or worsening of jumper's knee. Other risk factors are training and playing hours of at least 12 hours per week and/or in combination with weight training of at least 5 hours per week, and/or with playing or training on a hard surface. We did not find a specific occupational risk factor.
authors: Coronel Institute of Occupational Health, Academic Medical Center (AMC), University of Amsterdam, PO Box 22700, 1100 DE Amsterdam, The Netherlands. itiemessen@hotmail.com
authors: Ivo J H
authors: IJ
authors: Tiemessen
authors: P Paul F M
authors: PP
authors: Kuijer
authors: Carel T J
authors: CT
authors: Hulshof
authors: Monique H W
authors: MH
authors: Frings-Dresen