Dynamic ultrasound assessment of subacromial impingement

D: deltoid muscle; A: acromion bone; Hypoechoic line between the arrows: subacromial-subdeltoid bursa; SS: supraspinatus tendon; MED: medial; GT: greater tuberosity of humerus bone.
Left: medial; Right: lateral; Bottom of screen: deep; Top of screen: superficial.