Abstract: Lateral epicondylalgia [LE] is most common cause of elbow pain attributed to abnormalities in the extensor carpi radialis and extensor digitorum communis [EDC]. Quantifying the linear displacement using musculoskeletal ultrasound and the Motion Tracking Analysis Program [MTAP] may be useful in characterizing the abnormalities found in elbows with LE. This study investigated the reliability of the operators [i.e. sonologist and sonographer] and the reader [i.e. physiotherapist] in procuring and analyzing ultrasound videos using MTAP.