Hyperextending wiper

What causes a windshield wiper to hyperextend? My daughter is driving a 95 Hyundai Accent and she is having trouble with the wipers. The bolt seems to loosen, she has been keeping it tightened, and now the wiper is starting to hyper extend.

Maybe Since It Has Hyperextended And Loosened The Nut, It has Worn The Splines On The Shaft Or Wiper Arm.

It might need a shaft, wiper arm, or both, replaced. Slipping on the shaft will loosen the nut. It’s hard to tell from here.

Be careful the wipers are not frozen with ice when they are turned on. This will do damage.

Does “Hyperextend” mean that the wiper blade is touching areas that it normally would not? Travel is extended on both the up-swing and down-swing?

My guess is that something is worn enough that tightening the bolt is no longer enough. Without being able to see the wiper arm or the shaft that drives it there’s no way for us to know which is worn.