Hulk gives reason for back injuries and it's all about Bending over!!

So We told you Hulk Hogan was arrested, but now we know why.

Hulk was hospitalized yesterday for severe back pain – during a completely non-violent, low-impact session of ... seashell collecting.

Hulk -- who's had multiple back surgeries in the past -- says he must have aggravated his old injuries ... because the next morning he could "barely move" and had to call an ambulance.

Doctors believe he suffered a tear in one of his muscles -- but they still need to run some tests to be certain.

Guess The constant 'bending over' eventually got the better of him.