High expsoure for our talents

Often, these young promising players who are promoted from the junior to the senior level experience a rapid increase in their training volume and competition volume.


Training volume and body composition have been suggested as risk factors for jumper’s knee among athletic youth, but research is lacking.


Long-term project - start in 2006

PhD student MD Håvard Visnes and his supervisor Professor Roald Bahr have spent years on analyzing risk factors for the development of jumper´s knee among young Norwegian elite volleyball players.


A total of 141 healthy students (69 males and 72 females) have been recruited and followed prospectively for 4 years. Training and competition load were recorded continuously and body composition semiannually. Jumper’s knee was diagnosed on a standardized clinical examination.


Every 5th player with jumper´s knee

A total of 28 players (22 boys and 6 girls) were diagnosed with jumper´s knee, synonymous with every 5th out of the initially healthy recruited players. In addition, the researchers found a clear association between sex and risk. Throughout the 4-year period, male volleyball players had a 4 times higher risk to develop jumper´s knee than their female counterparts.


High volume of training and match play clear risk factors

This study revealed that the risk for jumper´s knee increased by 2-4 times with every additional weekly practice hour and volleyball set played.

Visnes and Bahr did not detect any significant differences between the groups in body composition at the time of inclusion or in the change of body composition during the study period.



One lesson learned from this study is that there needs to be a focus on how to control the total playing intensity theses talents are exposed to: how many different teams should youth players represent during the season and how many matches should they play. These issues are unlikely to be raised by the player; this is the responsibility of the coaching staff!


The results have been published in Scandinavian Journal of Medicine in Science and Sports.