Q. Does the scapular move in an upward or downward rotation with push up?, pull ups? and/or chin ups? I am having difficulty understanding. I cannot find a good source to explain it.

A. Upward and downward rotation of the scapula is best exemplified with shoulder motion occuring in the coronal plane/anterior axis such as  abduction and adduction movements of the shoulder (think jumping Jacks). Pull-ups with the start position of the arms overhead are considered downward rotation of the scapula (in the start position with the arms overhead, the scapula is already upwardly rotated and as the body is pulled upwards towards the bar, the scapula rotates downwards from its original upwardly rotated position). See Vid 1.

Push ups retract and protract the scapula and with chin ups, the shoulders move in the lateral axis (i.e. more of shoulder flexion/extension movements). Therefore, with these last 2 movements (push ups and chin ups), there is no scapular rotation. vid 2. describes the basic scapula motions.