Video game mythbusting channel VSauce3 have done their best to logically translate the force and effect of the dragon punch, based on how it’s been depicted in the series for decades, and use physics to re-create the damage in a real-world setting. As it turns out, the act of moving from a crouching position to leaping many feet off the ground and punching a person so hard that they fly up in the air with you is a superhuman feat. By their calculations, taking a dragon punch to the chin should knock your head clean off. Fatality.
To make their calculations, the team started with a specific animation from Street Fighter II: Ken using his dragon punch on a stunned Zangief. From there, they used physics to determine how much force it would take and a person for a fist to launch a Zangief-sized person a full body-length up in the air. From there, they calculate how high —more than 20 feet— and how fast —more than 20 miles per hour— Ken could jump if he didn’t hit anybody.
To re-create the shoryuken in the real world, they use a robot arm and a head-and-torso shaped target. They made the right decision.
Obviously this is all speculation: The “science” and math employed is based on the premise that Street Fighter moves were animated to scale and exist in a world where the laws of gravity apply. Their logic seems fine, as good as you can hope for, but ultimately the Street Fighter universe and reality are world apart.
All of this, by the way, is an extremely roundabout way of reminding you that the human body is very fragile… So do not try this at home. Getting punched in the face no fun, even without super-dragon powers.