Shoulder Controlled Articular Rotations (CARs) work wonders for the shoulder (glenohumeral) joint because they train full flexion, extension, internal, and external rotation under voluntary muscular contraction. Constant exposure to CARs allows the shoulder to adapt overtime and develop a more resilient joint.
However, there is one main issue when it comes to executing your shoulder CARs properly.
I often find that clients are unaware of their body's position while performing these rotations, which leads to compensations that minimize the effectiveness of CARs. In the video below, I explain the common compensations I see with CARs and a seated variation to help eliminate any movement that isn't created by the shoulder.