In order to have good diaphragm mechanics on inhalation, you must first master exhalation and be able to acquire a “zone of apposition” (or ZOA). Dr. Sarah Petrich defines ZOA, and the corresponding diaphragm biomechanics.

The adduction drop test and apical expansion tests were used with permission from the Postural Restoration Institute®.

About Sarah Petrich, PT, DPT, PRC, NCPT:

As a specialist in Postural Restoration, Pilates, & Dance Medicine, Dr. Sarah Petrich provides physical therapy and Pilates training focusing on re-balancing posture, alignment and breathing for patients and wellness clients. When not in the clinic or on zoom, she's often traveling around the nation teaching educational courses to healthcare professionals, Pilates instructors and other movement specialists. You can find her and her courses on her website www.sarahpetrich.com or on Instagram at @drsarahpetrich.