The cross-sectional area of the Achilles tendon measured using ultrasound. Example of the cross-sectional area of the Achilles tendon measured at the level of the malleoli using B-mode ultrasound. The area of the tendon outlined by the dashed white line and shaded in blue was calculated using ImageJ. A is anterior and P is posterior. The hyperechoic region anterior to the shaded ellipse around the tendon is Kager’s fat pad.