Patellar Tendon Stiffness in Elite Breakdancers Assessed by Myotonometric Measurement

Abstract

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.