April is stretching her shoulder by extending her arm up and slowly rotating it back until she experiences mild discomfort. She then holds that position for 30 seconds. By this description, April is performing stretching.

Static Stretching

Explanation:

This is a form of exercises,  performed in such a way that  joint(s) are placed in a stationary position, for muscles and connective  to attain maximum stretch, and  with   tissues fixed to the same  point to attain  maximum length. The stretch should be for 10-15 seconds ,  with minimum force applied.The subject should be well relaxed during the procedures to reduce resistance.

Static stretching improves  blood flow, reduces stress, and  reduces stiffness at joints and prevent damages,