Alvin Christian "Al" Kraenzlein (December 12, 1876 – January 6, 1928) was an American track-and-field athlete known as "the father of the modern hurdling technique".

[4] Kraenzlein was born in Minneapolis, Minnesota, a son of Johann Georg Kränzlein, a brewer, and Maria Augusta Schmidt, both of German origin.

In 1896, he won the 220-yard low hurdles, the high jump and placed second in the 100-yard dash and shot put at the freshman-sophomore track-and-field meet.

[5] In 1898, after being recruited by Mike Murphy, the University of Pennsylvania track-and-field coach, he moved to Philadelphia, where he studied at the Dental School[clarification needed], graduating in 1900.

Arthur Croome from Great Britain first attempted the straight-lead-leg style in 1886, however, Kraenzlein perfected it and turned into a mainstream technique.

[7][8] before entering the 1900 Summer Olympics in Paris, where he established a world record in the 120 yards hurdles for grass tracks.

In His victory in the long jump, Kraenzlein defeated silver medalist Meyer Prinstein, his great rival from Syracuse University, by a single centimeter.

He practiced dentistry in Philadelphia until 1906, when he became the track-and-field coach at Mercersburg Academy, a selective prep school in Pennsylvania.