Limitation of External Rotation or Abduction of Humerus
There are two muscles between the Scapula and the ribs, Subscapularis and Serratus Anterior. Between these two muscles is a bursa, the Supraserratus Bursa.
Right Shoulder – Transverse Plane View
This technique helps to give some separation between these two muscles.
With your client supine, press into the Subscapularis, pinning it with your fingers. Have your client slowly roll away so that the Serratus Anterior is lifted off the Subscapularis.
If your client is sufficiently masochistic, you may have them abduct their arm while turning away, giving them a stretch to the Subscapularis.
All work should be relatively pain-free. Have your client move slowly.
Thank you to Jody McComas for this technique.