This exercise will teach you how to eliminate excessive muscle tension in your shoulder girdle.
The following exercise has mainly two goals. If you think about them, you will realize that those goals are similar and not sharply distinguishable. Still it makes sense to state them as two goals as this will make it easier for you to realize what to focus on.
You will learn to use these practices effectively. As soon as you are able to do them, you can relax your shoulders pretty quick whenever you feel they are tightening up again. Also you will learn to let your arms and shoulders swing passively. In the long run this will make your gait smoother.
This may come in very handy if you feel that your jogging routine tightens up your shoulders for example.
Position yourself in a shoulder width stand. Raise your arms straight above your head. Make sure your arms are extended and close to your ears. Inhale into your belly.
Now let your arms collapse - do not let them fall straight in front of you - and let them swing at the sides of your body till they stand still. Exhale while you drop your arms.
Rest for at least 30 seconds and then repeat a couple of times.
To be able to let your arms swing passively, it helps to think of your arms of something that you are not able to move properly. Imagine you can feel but cannot move your arms. Now someone holds them up for you and then lets go of them. As soon as they get dropped, you just let them swing till they stop to do so.
During and afterwards the swings, feel how the blood is rushing from your shoulders into your arms. Concentrate on your shoulders and try to feel their weight. Feel how gravity pulls them down. Do not resist this pulling and just let it happen.
Also, during and after the swing, try to detect sensations in your arms. Where does the blood flow? Are there changes in temperature? Just try to make out changes and concentrate on the feeling that is created by those.
That is the important thing. Focus on change! But take your time. Do not rush. Take at least 30 seconds rest after your arms stopped swinging and concentrate on your shoulders and arms. Your body needs time to detect changes. And it needs this detection and those changes in order to realize what and where to adjust, respectively.
If you do not understand what I mean, I recommend reading my article about relaxation techniques.
This is almost exactly the same exercise like the dropping arms. The difference however, is that you do it with only one arm. Everything else stays the same.
Why? In the beginning some people may have difficulties to feel their shoulders and arms relaxing during and after the swing. To create a bigger contrast and thus a stronger sensation, just do the exercise with one arm.
By doing so, you will feel only one side swinging, getting more blood supply etc. while the other side remains almost unaffected. This creates a permanent contrast because one side is swinging, while the other is not, because one side gets the "blood rush" while the other does not, etc.
This will become so obvious that it will be, at least in the beginning, easier to relax with this exercise than with the dropping arms.
Also stand in front of a mirror and watch how your "working" shoulder sinks down in comparison to the other one. This visualization helps to make the exercise even more effective.