This article concerns what I will refer to as Pole-vault Pitching: whereby the pitcher executes a heel landing of the lead foot, which in turn, forces the leg to straighten upon impact - similar in nature to the planting of the pole in pole-vaulting. As shown here by pitcher Justin Verlander - the lead leg reaches the point of hyperextension after the ball is released: https://www.youtube.com/watch?v=mbVQc2gYjFQ
As Verlander’s throwing arm, which underwent Tommy John surgery last year, rotates forward to throw the ball downward toward the plate, we see that his straight-leg landing “pole vaults” his hips upward and actually backward with the hyperextension of his front leg. This in similar fashion to the pole in pole-vaulting, which shifts the vaulter upward as the pole bends backward: https://www.youtube.com/watch?v=XFMVEYvZ7Pw
Pitching instructors who promote this type of delivery call it Lead Leg Blocking. It is a method of putting on the brakes, so to speak. A growing number of “lead-leg-blockers” incorrectly assume that more energy (i.e., power = work/time) will be transferred to the throwing arm by this straight-front-leg “pole-vaulting” motion than for example, a bent-front-leg delivery, which I will point to shortly.
As a physics professor involved with physics in connection with human biomechanics (for various swinging and throwing type sports) I see this all together as “physics nonsense” as the particular goals are distinct: The goal of pole-vaulting is to transfer forward moving energy to upward moving energy via the pole. The goal of pitching a baseball at high velocity is to transfer as much energy forward as possible and continue to transfer this energy forward through the release of the ball. Only after releasing the ball do you want to put on the brakes. In other words, if you want to pole-vault, then onward and upward. If you want to pitch, then onward and forward (i.e., keep on keeping on).
Pole-vault Pitching is a sharp reminder (at least to me) of the snapping of the ulnar collateral ligament (UCL) similar to the snapping of the pole in pole-vaulting: https://www.youtube.com/watch?v=SKPLU_sVWII
The latest victim of Pole-Vault Pitching is the LA Dodgers Dustin May who employs a heel landing and the Lead Leg Blocking strategy in his largely all-arm delivery:https://www.youtube.com/watch?v=Mt_eYbyQXVI
Can you feel the searing pain in his elbow from his pole-vaulting delivery? https://www.youtube.com/watch?v=Q3Sf0EXSA1E
By contrast, the bent-front-leg delivery (used by so many of the pitching greats throughout the history of baseball) allows for the full (i.e., complete) and powerful rotation of the hips as Nolan Ryan demonstrates here: https://www.youtube.com/watch?v=-aZHPuss9jo
The durability of the pitcher will be enhanced by the bent-front-leg delivery and who better to demonstrate this for a full season than the last 30-game winner (31-6 in 1968) Denny McLain.
Finally, the fastest fastballer of all-time was a minor league pitcher few baseball fans have heard about Steve “Dalko” Dalkowski (1939 - 2020) who threw at least 110 mph (it has been reported by several reliable sources). Dalko threw with a bent-front-leg as shown below.
To find out more about this one-of-a-kind pitcher feel free to read the following article, which also directs the reader to a documentary film about his life by filmmaker Tom Chiappetta: