title: Evidence of accumulated stress in Achilles and anterior knee tendons in elite badminton players.
abstract: Tendon-related injuries are a major problem, but the aetiology of tendinopathies is unknown. In tendinopathies as well as during unaccustomed loading, intra-tendinous flow can be detected indicating that extensive loading can provoke intra-tendinous flow. The aim of present study is to evaluate the vascular response as indicated by colour Doppler (CD) activity in both the Achilles and patella tendon after loading during high-level badminton matches. The Achilles tendon was subdivided into a mid-tendon, pre-insertional, and insertional region and the anterior knee tendons into a quadriceps-, patella- and tuberositas region. Intra-tendinous flow was measured using both a semi-quantitative grading system (CD grading) and a quantitative scoring system (CF) on colour Doppler. Intra-tendinous flow in the Achilles and anterior knee tendons was examined in fourteen single players before tournament and after 1st and 2nd match, respectively on both the dominant and non-dominant side. All players had abnormal intra-tendinous flow (Colour Doppler ≥ grade 2) in at least one tendon in at least one scan during the tournament. At baseline, only two of the 14 players had normal flow in all the tendons examined. After 1st match, tendencies to higher intra-tendinous flow were observed in both the dominant patella tendon and non-dominant quadriceps tendon (P-values n.s.). After 2nd match, intra-tendinous flow was significant increased in the dominant patella tendon (P = 0.009). In all other locations, there was a trend towards a stepwise increase in intra-tendinous flow. The preliminary results indicate that high amount of intra-tendinous flow was found in elite badminton players at baseline and was increased after repetitive loading, especially in the patella tendon (dominant leg). The colour Doppler measurement can be used to determine changes in intra-tendinous flow after repetitive loading.
authors.affiliation: Institute of Sports Medicine, Bispebjerg Hospital and Center for Healthy Aging, Faculty of Health Sciences, University of Copenhagen, Bispebjerg Bakke 23, 2400 Copenhagen NV, Denmark. boesenanders@hotmail.com
authors.forename: Anders Ploug
authors.initials: AP
authors.lastname: Boesen
authors.forename: Morten Ilum
authors.initials: MI
authors.lastname: Boesen
authors.forename: Merete Juhl
authors.initials: MJ
authors.lastname: Koenig
authors.forename: Henning
authors.initials: H
authors.lastname: Bliddal
authors.forename: Soren
authors.initials: S
authors.lastname: Torp-Pedersen
authors.forename: Henning
authors.initials: H
authors.lastname: Langberg
mesh_terms: D000125:Achilles Tendon / Q000098:blood supply* / Q000000981:diagnostic imaging; D000328:Adult; D006801:Humans; D007719:Knee Joint; D017847:Patellar Ligament / Q000098:blood supply* / Q000000981:diagnostic imaging; D015865:Racquet Sports / Q000502:physiology*; D013710:Tendons; D018615:Ultrasonography, Doppler, Color; D055815:Young Adult