Coach, an excellent video, great graphics. I'd only add there's a good reason the discus doesn't accelerate until a bit later than most might expect. It simply lacks an "accelerant." From the the point out of the back of the ring at full backswing to begin the throw (zero velocity/acceleration), the body begins turning and driving discus velocity/acceleration via pivoting hips, swinging a wide right leg and also pushing off with the left leg. We might add that some here get added acceleration if they whip their left arms around. That's it; the discus is now in motion being dragged behind at a velocity and acceleration owing to these forces. Now, the thrower is airborne, has access to no accelerants and is, if anything, actively trying to slow the discus orbit, to stay "wound up," to maintain separation relative to the body. The thrower will use this "wound up position" to its advantage later. Then, the right foot landing in the ring's middle is a de-accelerating force (gravity vector/friction) and the same for the left foot as it lands at the front of the ring. But, you have your anchoring now, no longer "shooting a canon out of a canoe." So, there it is now awaiting another accelerant and you show it clearly to be the right hip/knee drive dragging the discus through with some visible acceleration. The Alekna tribe seems to have it all sorted out really well, that's for sure!
Newton’s first law applies to why the acceleration point is at the end of Discus traveling away from the sector. If the Discus is accelerating moving away from the sector it will take GREATER force to direct it back towards the sector. By waiting for the Discus to travel into a neutral direction which starts back towards the sector, more energy(force)can is available to be put into the throw instead of wasting it redirecting the Discus path back towards the sector. Gravity will bring the Discus into position without using energy reserves.
Coach, an excellent video, great graphics. I'd only add there's a good reason the discus doesn't accelerate until a bit later than most might expect. It simply lacks an "accelerant." From the the point out of the back of the ring at full backswing to begin the throw (zero velocity/acceleration), the body begins turning and driving discus velocity/acceleration via pivoting hips, swinging a wide right leg and also pushing off with the left leg. We might add that some here get added acceleration if they whip their left arms around. That's it; the discus is now in motion being dragged behind at a velocity and acceleration owing to these forces. Now, the thrower is airborne, has access to no accelerants and is, if anything, actively trying to slow the discus orbit, to stay "wound up," to maintain separation relative to the body. The thrower will use this "wound up position" to its advantage later. Then, the right foot landing in the ring's middle is a de-accelerating force (gravity vector/friction) and the same for the left foot as it lands at the front of the ring. But, you have your anchoring now, no longer "shooting a canon out of a canoe." So, there it is now awaiting another accelerant and you show it clearly to be the right hip/knee drive dragging the discus through with some visible acceleration. The Alekna tribe seems to have it all sorted out really well, that's for sure!
Newton’s first law applies to why the acceleration point is at the end of Discus traveling away from the sector.
If the Discus is accelerating moving away from the sector it will take GREATER force to direct it back towards the sector.
By waiting for the Discus to travel into a neutral direction which starts back towards the sector, more energy(force)can is available to be put into the throw instead of wasting it redirecting the Discus path back towards the sector.
Gravity will bring the Discus into position without using energy reserves.