Apparatus and method for characterizing tendon

Abstract

According to an example aspect of the present invention, there is provided at least a method comprising electrically stimulating a first muscle associated with a first subtendon of an Achilles tendon, AT, of a leg, said first muscle being one of: musculus soleus, lateral musculus gastrocnemius or medial musculus gastrocnemius, obtaining a first set of cross-sectional ultrasound images of the AT at a first location (440A), wherein the first set of cross-sectional ultrasound images comprises images obtained at a plurality of time points during stimulation of the first muscle, obtaining a second set of cross-sectional ultrasound images of the AT at a second location (440B) separated by a distance from the first location (440A), wherein the second set of cross-sectional ultrasound images comprises images obtained at a plurality of timepoints during stimulation of the first muscle; and determining, based on the first set of cross-sectional ultrasound images and the second set of cross-sectional ultrasound images, information on the first subtendon at the first location (440A) and the second location (440B).