Tiger Knee Motion

Not to be confused with the attack Tiger Knee, one of Sagat's Special Attacks
The Tiger Knee Motion is a community term for a motion in Street Fighter games that usually ends in the up-back or up-forward motion in terms of Inputs.

Origins
In the Street Fighter II transition from The World Warrior to Champion Edition the Boss Characters were overall toned down in power to be more competitive in battle. They recieved universal nerfs such as attacks now matching the standard rules in terms of damage and recovery (Sagat's far hard punch now has a recovery that matches the other far hard punches and can not be combo'ed into itself for example).

Despite the nerfs some the bosses did get buffed in some areas, for example despite losing his Scissor Kick block infinite from World Warrior, M. Bison's Psycho Crusher gained a much faster startup, doesn't get affected by double damage when hit, and hits many more times on block. For Sagat, while he got a massive Tiger Shot nerf that made it's startup and recovery more comparable to Hadouken compared to it's previous high damage and faster than Sonic Boom recovery, his two main buffs were that his Tiger Uppercut no longer gave him double damage if he was hit out while executing the attack and he got a new attack that helped his limited mobility in Tiger Knee.

In the CPS1 Street Figthter II games, this attack had a unique at the time input that was only rivaled by Zangief's Spinning Pile Driver in awkwardness of execution. The input ended with an "Up-Right" motion. After The New Challengers was released, Sagat's Tiger Knee would be switched to a more conventional "Shoryuken" input. However as Street Fighter games became more complex players have found this motion useful for other purposes than it was originally made for.

Tactics
The Tiger Knee Motion is now used in competitive for two main purposes. The first is for Jump Cancels such as Ibuki's crouching hard punch into Neckbreaker. The other in "Instant" air attacks. For the Tiger Knee Motion to be practical the attack has to have either no or a very low to the ground Height Restriction. Cammy's Cannon Strike has become synonomys with the input due to her EX Cannon Strike being able to be performed off a backjump. This tactic is used to bait Tech attempts, Crouch Techs, or even Tick Throw. It is recomended for players who play characters with aerial attacks that have very low height restrictions to familiarize themselves with the timing of the motion for their characters.