Ecologically dynamic flywheel ergometer squat performance characteristics between national Olympic athletes with and without patellar tendinopathy

BACKGROUND: Patellar tendinopathy (PT) is a common injury involving inadequate eccentric (ECC) knee extensor contractions during dynamic sports activities. However, any discrepancies in ECC power output between Olympic athletes with and without PT utilizing a flywheel ergometer squat remain to be determined. OBJECTIVE: To compare peak ECC power, concentric (CON) power, the ECC/CON power ratio, and performance speed in female and male athletes with and without PT, respectively. METHODS: Forty Olympic athletes with and without PT were included and analyzed for ECC power, CON power, ECC/CON power ratio, and performance speed (m/s) under varying load conditions, with analyses separated by gender. RESULTS: The ECC power, ECC/CON power ratio, and performance speed of the PT group were significantly lower than those of the non-PT (NPT) group in both genders. ECC and CON power significantly increased with higher inertial loads in the NPT groups, whereas the speed significantly decreased as the inertial load increased in both PT and NPT groups. CONCLUSIONS: Dynamic flywheel ergometer assessments may help in the quantitative diagnosis of athletes with PT under differing dynamic squat conditions. This assessment may be used to create standardized guidelines for squat performance testing, strengthening, conditioning, and rehabilitation.