Fig. 3

a Probe positioning for imaging the lateral epicondyle of the humerus (white arrow). While the insertion of the common extensor tendon is imaged, both the lateral epicondyle and the radial head is captured for consistency. b Longitudinal image of the lateral epicondyle demonstrating acoustic shadowing (white arrow) from the Post-it® arrow. For imaging reproducibility, the landmark for scanning lateral epicondyle includes radiocapitellar joint (white star) deep to the extensor tendon (yellow star)