Horizontal shoulder flexion/adduction stretch seated ("Cross arm stretch" Shoulder horizontal abductors stretch, sitting)

Sit upright in a chair.
Move your arm gently across your chest at the height of your shoulder.
With your other hand, gently hold your elbow and pull your arm further across.
You should feel the stretch across the back of your arm and shoulder.
Hold this position as directed and then repeat to the other side.
This exercise stretches the muscles in your upper arm, upper back and shoulder.