Table 3. The measurement position and method for scapular stabilizing and shoulder large muscles.

	Posture	Transducer position	Image
Upper trapezius	Prone	Spinous process at the level of C6	Triangular shaped medial portion of the muscle
Lower trapezius	Prone	Spinous process at the level of T8	Medial portions of the muscle belly
Serratus anterior	Side-lying	Superior to the peak convexity of the most distal rib	Between the superior and inferior echogenic fascial lines
Supraspinatus	Seated	Center of the supraspinous fossa	2cm from the angle formed by the superior muscular fascia of the supraspinatus
Infraspinatus	Seated	Center of the infraspinous fossa	2cm from the angle formed by the superior muscular fascia of the infraspinatus
Rhomboid major	Seated	Center of two lines: the middle of the line from T2 to the root of the scapular spine and the middle of the line from T5 to the scapular inferior angle	Vertical length between the inferior echogenic fascial line of the trapezius and the superior line of the posterior serratus
Pectoralis major	Stood	Between third and fourth of costa under the clavicle midpoint	Between the subcutaneous adipose tissue–muscle interface and the muscle–bone interface
Middle deltoid	Seated	Superior surface of the acromion process of the scapula	Quarter of the distance from acromion to the lateral epicondyle

Side-lying: Side-lying with shoulder supported in 90° flexion