Abstract

Objective: To analyze and compare the viscoelastic properties of the Achilles and patellar tendons in elite athletes from different sports and determine whether there are significant differences attributable to sport-specific mechanical loading.Methods: This is a cross-sectional study in which a total of 105 elite athletes (33 females; 72 males) from 11 distinct sport disciplines (road cycling, roller hockey, karate, athletics, volleyball, taekwondo, speed skating, judo, archery, handball, and boxing) were evaluated at a national high-performance sports center. The viscoelastic properties (stiffness, relaxation, decrement, among others) of both tendons were measured bilaterally using a portable myotonometry device (Myoton Pro®, Myoton, Tallinn, Estonia). The primary outcome was tendon stiffness. Results: Significant differences were found in all measured variables for both tendons (p < 0.001) across sports, except for the decrement parameter in the patellar tendon (p = 0.45). The Achilles tendon demonstrated greater sport-specific adaptation, with stiffness showing the highest number of inter-sport differences (29 significant pairwise comparisons). Relaxation was the most variable parameter in the patellar tendon (9 significant comparisons).Conclusions: The findings demonstrate that the viscoelastic properties of the Achilles and patellar tendons differ significantly based on the sport practiced by elite athletes. This suggests that long-term, sport-specific mechanical loading plays a crucial role in tendon adaptation, leading to functional specialization. While the cross-sectional design precludes causal inference, these results provide valuable reference data for training prescription and injury prevention strategies tailored to specific athletic disciplines.