SEGA thumbs 

Pain or stiffness in the thumbs occuring most often after a long bout of playing a game on the SEGA console.
Can also be applied to other consoles.

After 5 hours of Sonic, Bruce had a badass case of SEGA thumbs.

SEGA thumbs by The Professor June 28, 2004

SEGA thumbs 

Sega Thumbs are human thumbs that bend backwards, under their own power, so far as to reach a Reverse Right-Angle. Almost all of our thumbs bend forward 90 degrees. The Left or Right Reverse Right-Angle is a feat most often achieved by Sega fans who were around when the games we are playing on our cell phones were the games that were proudly displayed on our brand new WOOD TVs!
Bonus1:Using 1 or more Sega Thumbs speeds up Text Messaging.
Bonus2:Hitch-Hiking with Sega Thumb is a guaranteed ride.
Bonus3:Sega Thumbs give great Massages.

Question-
"Honey, I'll give you head if you give me 20 minutes of your Sega Thumbs? I have a really sore back"
Answer-"Right after this game Babe E!"

SEGA thumbs by Quad Hizzo the System Master February 6, 2007

SEGA thumbs 

A disease caused by playing Sonic Spinball on the Sega MegaDrive for 57 hours straight. Known to lead to cripplingly premature arthritis.

Ow my thumbs bend back on themselves. Must be Sega Thumbs.

SEGA thumbs by Anonymous June 26, 2003