Okay, so at work I deal with large kiosks, and in the back of the kiosk is a cabinet space with a wooden door that flips upward to open. It opens at about 3 feet off the ground, so if you flip it up all the way against the back of the kiosk, the edge of the door is about 6 feet off the ground.

My coworker was holding it in that position for me while I grabbed the electrical cord from the cabinet and plugged it in. When I turned around and bent down a little to move the cord, he dropped the door right onto the top of my head (apparently not realizing I would be underneath it). Since I was bent over a little it may have dropped about a foot or more outward and a foot downward before hitting my head (I’m 6 feet but was bending so my head may have only been about 5 feet off the ground). The door is made of thin particle board, but the top edge of it, which is what hit my head, has about a 1-inch thick wooden bar on it. Overall, the door is about 3 feet tall by 3.5 feet wide, so it is fairly heavy.

I have had worsening headache and other symptoms in the 36 hours since this occurred.

How much force would this have been if it dropped at free-fall speed (not sure if my coworker was still holding onto it at all)? And would this have caused a concussion?