Springfree Trampoline - That's Dr. Keith Alexander, inventor of the Springfree Trampoline showing off his awesome moves! Jumping makes us feel super happy inside! But tell us, how does jumping make you
![RENKERT Alexander (USA) M - 2019 Trampoline Worlds, Tokyo (JPN) - Qualification Tumbling R1 - YouTube RENKERT Alexander (USA) M - 2019 Trampoline Worlds, Tokyo (JPN) - Qualification Tumbling R1 - YouTube](https://i.ytimg.com/vi/l0VRND5JKzo/maxresdefault.jpg)
RENKERT Alexander (USA) M - 2019 Trampoline Worlds, Tokyo (JPN) - Qualification Tumbling R1 - YouTube
![Alexander Rusakov of Russia competes during the men's trampoline competition at the 2004 Olympic Games in Athens, Saturday, Aug. 21, 2004. (AP Photo/Amy Sancetta Stock Photo - Alamy Alexander Rusakov of Russia competes during the men's trampoline competition at the 2004 Olympic Games in Athens, Saturday, Aug. 21, 2004. (AP Photo/Amy Sancetta Stock Photo - Alamy](https://c8.alamy.com/comp/2PER114/alexander-rusakov-of-russia-competes-during-the-mens-trampoline-competition-at-the-2004-olympic-games-in-athens-saturday-aug-21-2004-ap-photoamy-sancetta-2PER114.jpg)
Alexander Rusakov of Russia competes during the men's trampoline competition at the 2004 Olympic Games in Athens, Saturday, Aug. 21, 2004. (AP Photo/Amy Sancetta Stock Photo - Alamy
![RENKERT Alexander (USA) M - 2019 Trampoline Worlds, Tokyo (JPN) - Qualification Double Mini R1 - YouTube RENKERT Alexander (USA) M - 2019 Trampoline Worlds, Tokyo (JPN) - Qualification Double Mini R1 - YouTube](https://i.ytimg.com/vi/hAih8qAo4xs/sddefault.jpg)
RENKERT Alexander (USA) M - 2019 Trampoline Worlds, Tokyo (JPN) - Qualification Double Mini R1 - YouTube
![Keith Alexander's invention took 15 years and has made $55 million, but he doesn't own it | Stuff.co.nz Keith Alexander's invention took 15 years and has made $55 million, but he doesn't own it | Stuff.co.nz](https://resources.stuff.co.nz/content/dam/images/1/n/i/4/c/u/image.related.StuffLandscapeSixteenByNine.710x400.1ni4ch.png/1513715649304.jpg?format=pjpg&optimize=medium)