Kronig isthmus

Kronig isthmus is a band of resonance representing the apex of lung, also it's described as the narrow strap-like portion of the resonant field that extends over the shoulder, that connect the larger areas of resonance over the pulmonary apex in front and behind.

Boundaries

 * Medially: Scalene


 * Laterally: Acromion process


 * Anteriorly: Clavicle


 * Posteriorly: Trapezius