The effects of growth on structural properties of the Achilles and Patellar tendons: A cross-sectional study

The purpose of this study was to investigate the structural properties (length and cross-sectional area) of both the Patellar and Achilles tendons at around adolescent growth spurt. One hundred-twenty children and adolescents participated in this study. Based on estimated age at peak height velocity, the participants were separated into three groups (before takeoff of adolescent growth spurt group, from takeoff of adolescent growth spurt until peak height velocity group and after peak height velocity group). An ultrasonography technique was used to determine structural properties of the Patellar and Achilles tendons. Significant group difference was observed in tendon length for the Patellar and Achilles tendons among groups. However, there were no significant differences in the ratio of the Patellar tendon to upper leg length and the ratio of the Achilles tendon to lower leg length among groups. The cross-sectional area of all regions for the Patellar and Achilles tendons in adolescents with after takeoff adolescent growth spurt group was greater than those of before takeoff adolescent growth spurt group. These results indicate that the cross-sectional area of both the Patellar and Achilles tendons increase with takeoff of adolescent growth spurt and tendons lengthen without the changes in the ratio of tendon length to bone length. In addition, the increases in the cross-sectional area of both the Patellar and Achilles tendons occur in whole regions but not specific regions.