Background:Tendon overuse injuries are an issue in elite footballers (soccer players) and may affect tendon function. Achilles and patellar tendinopathy are the most frequent pathologies. Tendon stiffness, the relationship between the force applied to a tendon and the displacement exerted, may help represent tendon function. Stiffness is affected by training and pathology. Nevertheless, information regarding this mechanical property is lacking for elite soccer athletes.Hypothesis:Achilles and patellar tendon stiffness assessed using myotonometric measurements will be greater in elite soccer athletes than in control participants.Study Design:Cross-sectional study.Level of Evidence:Level 4.Methods:Forty-nine elite soccer athletes and 49 control participants were evaluated during the 2017 preseason. A handheld device was used to measure Achilles and patellar tendon stiffness. Dominant and nondominant limbs were assessed for both groups.Results:A significantly stiffer patellar tendon was found for both the dominant and the nondominant limb in the elite soccer athletes compared with the control group. Nevertheless, no differences were found in Achilles tendon stiffness between groups. When comparing between playing positions in soccer athletes, no significant differences were found for both tendons.Conclusion:Greater patellar tendon stiffness may be related to an improvement in force transmission during muscle contraction. On the other hand, it seems that after years of professional training, Achilles tendon stiffness does not change, conserving the storing-releasing function of elastic energy. The nonsignificant differences between positions may be attributable to the years of homogeneous training that the players underwent.Clinical Relevance:The present study shows another technique for measuring mechanical properties of tendons in soccer athletes that could be used in clinical settings. In the future, this technique may help clinicians choose the best exercise protocol to address impairments in tendon stiffness.

Studies that have investigated the epidemiology of injuries in breakdancing have concluded that the second most common injury site is the knee and that the majority of breakdancers have experienced overuse syndrome. Tendon stiffness, the relationship between force applied to a tendon and the resulting displacement, has been identified as a primary mechanical factor in such injuries. However, patellar tendon stiffness has not yet been evaluated in elite breakdancers. Hence, the purpose of this study was to determine mean patellar tendon stiffness in this population by using myotonometric measurements and to compare those results with healthy control subjects. Twenty-five elite male breakdancers and 25 male control subjects were included in the study. A Myoton Pro device was used to assess their tendon stiffness. The mean patellar tendon stiffness of the breakdancers was 1,045 ± 202 Nm and 1,084 ±193 Nm for the dominant and non-dominant limb, respectively; for the control group it was 902 ±166 Nm and 862 ±159 Nm for the dominant and non-dominant limb, respectively. Statistical analyses showed higher stiffness values for breakdancers compared to controls for both limbs. This is consistent with studies reporting patellar tendon adaptation after training.

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