This is just a little anatomy rant about lifting the arms (shoulder flexion- atanomically speaking).
As someone who has studied movement anatomy, I have a few pet peves when it comes to cueing anatomically. It's taken years of learning and cueing myself to gain a deeper understanding of anatomy principles plus staying up to date on current research and trends. I understand that most normal people do not know much about anatomical movements of the joints, but as a fitness professional it is important to understand them. If you are a fitness professional who does not have an exercise science/kinesiology background, I recommend taking an "Anatomy" class through the Kinesiology department where the focus is on the musculoskeletal system in movement (not an anatomy class sometimes found in health departments that details the urinary, reproductive, endocrine, or digestive systems). Since I'm ranting about an overhead arm movement, lets look at shoulder movement in relation to the scapularthoracic joint.
I think a lot of cues get distorted through simplification, over simplification (which is what we do for our clients!) and not understanding the origin for the cue. For example, in Pilates and Yoga, when we lift the arms over head (whether it be in the frontal or saggital plane) we don't want our clients to hunch their shoulders to towards their ears. First off, that looks super uncomfortable and secondly, many people just cannot do it (for a number a reasons, see Brent Brookbush video below). Instead of having them simply not raise their arms as high, we cue the entire class to "keep your shoulders down and back." I'm sure you've heard the cue before! Or we might say something like "if you notice it's difficult to straighten your arms, or your shoulders are touching your ears, or your thoracic spine extends, lower you arms or bend your elbows to a more comfortable position" and of course the one person you were trying to cue just doesn't get it!
Why is this important? The cue "keep your shoulders down" is fine until your arms move above shoulder height. Once they pass shoulder height your scapula must upwardly rotate to create some space in the glenohumeral joint to prevent impingement. So basically, the shoulder is going to look a little bit lifted. If you went to a physical therapist and they measured your shoulder range of motion and your shoulder blade did not move as you move your arm, that would be considered an unusual movement patern.
I work with several seniors and men who have a hard time even elevating their scapula, think of the functional disadvantage they are at when going into shoulder flexion (raising their arms overhead). Think about your shoulder joint and movement of the scapula when brushing/washing hair, putting on bra, t shirt, reaching things from the kitchen cabinets (especially if your short like me). Try putting on a t shirt and "keeping the shoulders down," why the heck would anyone want to do that? I do not want my older adult clients to hear it!
Here are a couple great links about "lifting the arms" and shoulder cues: