Rene is trying to stimulate the flexibility of her shoulder and so has added shoulder stretches to her warm up routine.
Flexibility is a physical valence related to the ability to perform amplitude movement. Therefore, the greater range of motion, the greater the flexibility of the joint. Flexibility is specific by articulation, and the individual can be flexible in one joint and rigid in another. Stretching, on the other hand, is a set of exercises that can be used to train flexibility, promote muscle warm-up and muscle relaxation.
C.) Air pressure. Air pressure has nothing to do with breathing really. Air pressure is the pressure brought by the weight of air in the atmosphere of Earth.
