Fatigue-induced Alterations of the Patellar Tendon in Elite Sprint Track Cyclists

Abstract

The study aims to investigate morphological and mechanical properties and echogenicity of the patellar tendon (PT) after acute fatigue-induced alterations in sprint track cyclists. Fourteen elite track cyclists participated in this study. The exercise protocol consisted of three (on a distance of 62.5 m), one (125 m and 250 m) maximal start accelerations, and sprints from the standing start. Immediately after testing all measurements, PT stiffness and thickness were set at 5-10-15-20 mm distal from the apex of the patella and 5-10 mm proximal to the tibial tuberosity. CSA was set at proximal, middle, and distal, while echogenicity was at proximal and distal points. The results showed significant increases in PT stiffness at all reference points after start acceleration (p<0.001). PT thickness showed similar results as for stiffness, however except for location placed at TT-5 (p<0.001). CSA increased significantly in proximal, middle, and distal regions (p<0.001), while echogenicity of tendon increased in proximal and distal regions (p<0.001) after start acceleration. Regional-dependent alterations of PT thickness and stiffness may be related to anatomical and physiological mechanisms due to acute isometric contraction in the initial phase of standing start. Tendon echogenicity might be also useful in monitoring tendon mechanical properties and defining acute fatigue-induced changes.

Effect of applied cadence in repeated sprint cycling on muscle characteristics

“…The reason for different recovery could be explained by different muscle load (Csapo et al 2011 ). Still, our results showed that repetitive sprints did not enable full recovery 1-h post-exercise of morphological properties and architecture of the quadriceps muscles regardless of the cycling cadence underlining risk of overuse (Klich et al 2023 ). In summary, we observed greater alterations in morphological properties and muscle architecture, especially in VL at optimal cadence compared with 70% of optimal cadence.…”

“…There was also a significant increase in QT and PT thickness immediately after the sprint cycling protocol at an optimal cadence contrary to the findings reported in previous review papers (Obst et al 2013 ; Tardioli et al 2012 ). We have previously reported an increase in these tendons after fatigue-induced protocol (Klich et al 2023 ), and after individual pursuit races (Klich et al 2020 ). This observation could be explained by the high-intensity loads leading to tendons thickening (Fisker et al 2017 ).…”

“…Ultrasound imaging has been used over the preceding two decades to evaluate the quadriceps muscle and tendons alterations after different fatigue-induced protocols, including laboratory and field-based environments (Klich et al 2023 , 2020 ; Bouillard et al 2014 ; Brancaccio et al 2008 ), and has shown excellent reliability (Blazevich et al 2006 ).…”