The half-kneeling position provides so many benefits, including local core stabilization, anchoring the pelvis, and challenging the body in all 3 planes of movement. The movement is first broken down into three parts as I describe in the video, SOUND ON people! As you can see thoracic rotation and shoulder flexion in the scaption plane is achieved. If raising your arm straight ahead is 90 degrees, and out to your side is 0 degrees, the scaption plane is 30 degrees from the frontal plane. Why perform shoulder flexion in the scaption plane to 120 degrees with an added 'reaching punch'? Well it has been shown to be one of the best exercises for the serratus anterior, the main stabilizer of your scapula (shoulder blade). Without trunk and scapular stability, the overhead athlete cannot depend on longevity of shoulder stability. I've said it before and I'll say it again, BREATHE during this exercise people and keep control of that scapula!