Nikolai Sotsky is a Ph. D, Dean of the Bio-Mechanics College at the University of Minsk, Belarus. Dr. Sotsky invented Bison-1, personal strength exerciser, in 1992, which has rapidly spread around Europe due to its efficiency for forearm and wrist strengthening. In this video Nikolai Sotsky presents Bison-1 (the older design) and demonstrates what anyone using Bison-1 can reach - tying, what became famous as Sotsky Knot (2:35), - a knot from two nails of 6mm in diameter and 200mm in length. Remember that about 99.5% of all people cannot even budge one of these nails, and Dr. Sotsky is over 50 years old. ***This is an older version of the promotional video.