Insufficient accuracy of the ultrasound-based determination of Achilles tendon cross-sectional area

Besides the dependency of the CSA determination from the observer, the ultrasound method is not sensitive enough to detect physiological changes in tendon morphology of the magnitude that is reported by intervention studies. Furthermore, the validity analysis revealed a lack of agreement between both methods. Therefore, the ultrasound-based methodology cannot be recommended for an accurate Achilles tendon CSA determination in vivo.