Obsolete Russian units of measurement Peter the Great replace it with the Hindu-Arabic numeral system. The basic unit is the Russian cubit, called the "arshin", which has been in use since the 16th century. It was standardized by Peter the Great in the 18th century to measure exactly twenty-eight English inches (). Thus, 80 vershoks = 20 piads = 5 arshins = 140 English inches (). A "piad" (, “palm”, “five”) or "chetvert" (, “quarter”) is a hand span, the distance between ends of the spread thumb and index finger. Alternative units: As in many ancient systems of measurement the Russian distinguishes between dry and
Ulnar collateral ligament injury of the elbow near full supination, and the elbow flexes from 90° to approximately 125°. From late cocking to ball release, the elbow rapidly extends from approximately 125° to 25° at ball release. This causes tremendous valgus stress and tensile strain on the UCL. Injuries to the ulnar collateral ligament are believed to result from poor throwing mechanics, overuse, high throwing velocities, and throwing certain types of pitches, such as curveballs. Poor mechanics along with high repetition of these overhead movements can cause irritation, micro-tears or ruptures of the UCL. Injuries to the Ulnar Collateral Ligament in baseball players are rarely due to