Science Arms 

Skinny, typically pale arms, associated with nerdy unathletic folks. also see: Science Legs Re-submitted to replace "Science Arms (Legs)" with 2 separate definitions

No way those 4 nerds can pick up that VW Bug - - those science arms couldn't push it forward if it were in neutral... let alone lift it off the ground.

Science Arms by Nice501s March 4, 2023

Science legs (arms) 

Used to describe skinny, often pale limbs.

Whoa. Did you see the Science legs (arms) on Bill Nye in that video!

-or-
Look at that nerdy white boy, swing his science arms around, pretending he can dance.

Science legs (arms) by Nice501s June 15, 2020