This rehab exercise is great for increasing core strength. The key is both position and timing, most people hold this exercise far to long to develop stability. Most people are surprised that you only need to hold the position for only 10 seconds but do multiple repetitions.
This exercise focuses on straightening the upper shoulders, rotator cuff and mid-thoracic area. (Traps, Rhomboids, posterior deltoid, and upper thoracic paraspinals)