Abbreviations: SAG: Sagittal; ANT: Anterior; MED: Medial; CEN: Central; LAT: Lateral The transducer positions used for sagittal anterior imaging acquisition of the anterior aspect of the elbow joint at the level L1 are shown. The positions of the transducer placed laterally (B), centrally (C) and medially (D) in relation to the central position of the joint are illustrated with accompanying sonographic images in a healthy volunteer. The distal humeral epiphysis (*) has been marked. The transducer positions used for sagittal imaging acquisition of the anterior aspect of the elbow joint at the level L2 are shown. The positions of the transducer placed laterally (E), centrally (F) and medially (G) in relation to the central position of the joint are illustrated with accompanying sonographic images in a healthy volunteer. The distal humeral epiphysis (*) and proximal epiphysis of the radius (**) and coronoid process of the ulna (***) have been marked. The transducer positions used for sagittal imaging acquisition of the anterior aspect of the elbow joint at the level L3 are shown. The positions of the transducer placed laterally (H), centrally (I) and medially (J) in relation to the central position of the joint are illustrated with accompanying sonographic images in a healthy volunteer. The distal humeral epiphysis (*) and proximal epiphysis of the radius (**) and coronoid process of the ulna (***) have been marked.

Figure 1: The locations delineated with gel in supine position represent the positions of the transducer for acquisition of sagittal anterior images. The levels shown are L1 SAG, ANT, LAT; L1 SAG, ANT, CEN; L1 SAG, MED LAT; L2 SAG, ANT, LAT; L2 SAG, ANT, CEN; L2 SAG, ANT, MED; and L3 SAG, ANT, LAT; L3 SAG, ANT, CEN; L3 SAG, ANT, MED.