Relationships between the Mechanical Properties of Patellar Tendons and Quadriceps Strength in Humans

Abstract

The mechanical and morphological properties of patellar tendons were in vivo measured during isometric knee extension contractions in ten male subjects using ultrasonography. The subjects were accustomed to various exercise and training. The stiffness, cross-sectional area, and tangent modulus of the patellar tendons were positively correlated with the quadriceps strength. The enhancement of contractile forces induced by exercise and training increases the quadriceps strength. Since the primary role of patellar tendons is the transmission of contractile forces from quadriceps to tibia, the contractile forces are directly applied to the patellar tendons. Therefore, in the subjects with the larger quadriceps strength, the forces applied to the patellar tendons during exercise and training may be larger, and the force enhancement may induce the increases in the stiffness, cross-sectional area, and tangent modulus of the patellar tendons.