A machine that brings out the effect by relaxing the upper body, move the shoulder blades up and down.
As the same time as the arm moves the shoulder blade moves in the maximum range of movement and relax the upper body.
Put your hands on the semicircular rotatable base and open up the shoulder joint.
Use muscle of arms to push down and then unlash until elastic resistance to effect and lift up shoulders to open the joint.
Internal/external rotation to obtain flexibility of wrist.
Even for the most rigid shoulders to perform the lightest strength.