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New PhD on talented young volleyball players and their risk to develop tendinopathy


On Friday, September 12, MD and PT Håvard Visnes will defend his PhD-thesis on «Risk factors for jumper’s knee» at the University of Bergen, Norway.

MD and physiotherapist Håvard Visnes has work on his research question why some athletes develop tendinopathy (jumper's knee), while others remain healthy through their careers. Visnes followed young talented students at an elite high school in volleyball at Sand, a small place on the west coast of Norway, over the period 2006-2011.

Most talent - highest risk

The main findings of the PhD-work is that boys are of 3-4 times higher risk of developing tendinopathy compared to girls without having the reason completely understood. In addition, those athletes with a natural ability for jumping high seem to be predisposed to develop jumpers´s knee (read the article).

Another key finding is that there are clear associations between high training and match exposure and the development of jumper´s knee.


High exposure for the 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.


As the total exposure to training and match play seem to be too high for the best players, coaches should evaluate each player´s schedule on how many different teams this young player should represent during the season and how many matches he/she should play.



If this evaluation is not taken care of, one can risk that the best players never will get the time for sufficient restitution and conditioning, and injury prevention training.


Athletes who develop tendinopathy are often those who specialize early in volleyball, and data indicate that early sport specialization may increase the risk of tendon injuries like tendinopathy (read the article).

Ultrasound screening?

Ultrasound was used to examine both quadriceps- and patellar tendon. The US examination clearly identified differences in mechanical and material properties between elite volleyball players with and without patellar tendinopathy.


In line with previous clinical findings, Håvard and his team found a larger proximal cross-sectional area of the patellar tendon in injured players compared to healthy.


Also, tendons with jumper’s knee presented 20% lower stiffness and 15% lower Young’s modulus compared to healthy tendons.


(to the right: Håvard Visnes)


However, the difference between counter movement and squat jump height was higher in the group with jumper’s knee compared to the group of healthy players (3.4 vs 1.2 cm). In other words, tendinopathic volleyball players were good in utilizing the stretch-shortening cycle when jumping.


This findings from this study question whether US screening will identify athletes at risk. In fact, there are a lot of athletes who have mechanical and material changes in the tendon, but subsequently do not develop problems (read the article).

More about Håvard Visnes

Håvard Visnes (born 1974) is a PT since 1998 and MD since 2006. His interest in sports medicine was triggered through volleyball where he won several national titles, in addition to playing for the national team. Håvard´s research is conducted at the Oslo Sports Trauma Research in Oslo under supervisor Professor MD Roald Bahr. In the period 2009-2014, Visnes worked in a research position at Kysthospitalet by Hagevik, while he is now working at the orthopedic department at Haukeland University Hospital in Bergen.

Contact Håvard Visnes, tel: 41449996, E-mail: haavard.visnes@helse-bergen.no


Read more about Håvard research


Trial lecture and PhD-defense on September 12, 2014 (Sted: Aud 1-Bygg for biologiske basalfag (BBB), Haukeland University Hospital, Bergen, Norway)


10:15-11:00: Trial lecture "The Hoffa fat pad-function and possible pain related structures;  Clinical implications, diagnostics and treatment"

12:15-15:00: PhD defense


Dissertation committee


Head: Prof MD Jon Arne Søreide


1. Opponent: Håkan Alfredson, Department of Surgical and Perioperative Sciences, Sports Medicine, Umeå University, Sweden

2. Opponent: Henning Langberg, Department of Public Health, University of Copenhagen, Denmark


Trial lecture and PhD-defense are open for public. Welcome!