Falls in the elderly

can be serious, very serious...so I am duly grateful that it wasn't.
The Senior Cat "just sort of slid over" in his bedroom at about 5:15 yesterday afternoon. He couldn't get up again.
No, he didn't call out to me immediately. He had not hurt himself. He could do this by himself - except that he couldn't. He was there for a good fifteen minutes before he called me.
I cannot lift him by myself. He is not a heavy person but he has reached that "awkward elderly" stage. He can't kneel any more - two artificial knees have done that.
So, I went for help. M... across the road was home. He's strong enough to help. 
I couldn't make them hear at the front of the house so I went down the side and knocked on the back window. S... his wife is a paediatrician and well used to handling such things. Of course M... would go and help. He was in the bathroom with the two small boys while S... finished getting their evening meal.
M... was on his way before I had properly seen to it that the two boys were safe. S... said she was fine with them because H... was sitting in the shower cubicle where there was no water. 
I came home and M... and I had to lift the Senior Cat between us.  
It is one of those things that Middle Cat knows about and she should have shown us how to do it. I know how we helped the children when I was working with severely disabled children but the Senior Cat is taller and heavier - even though he is not a big or heavy adult.  
S... had said she would come and check later if I was worried but I had asked the Senior Cat to do the "finger tip to nose test" and he did it easily. He didn't think he had hurt himself either so I sent a quick email saying I thought things were okay. Middle Cat will call in today.
But there are two things that need to said here. The first is that everyone should know the "finger tip to nose test". Ask the person to close their eyes and stretch their arms out as far as they can. Then ask them, still with their eyes closed, to put their forefinger on their nose (and repeat for the other side). If they can't do it then get them some medical assistance asap. Other things like slurred speech or confusion are obvious signs but I was taught test too.
The other is equally important. Know your neighbours. Know them at least well enough that they will know who you are if you knock on the door. It doesn't mean living in one another's pockets. 
We are incredibly fortunate in our neighbours. I went to M... and S.... as the people I felt the most comfortable about asking. M... is physically able to help. Our neighbours on one side are away at the moment but there were two more able bodied men across the road I could have asked. If they had all been out I could even have gone around the corner and got help from two more able bodied men. But I was fortunate, the first people I went to were home and could help.
I know it could happen again. I hope it doesn't and it may not but the Senior Cat has always been clumsy-pawed. He is just fortunate he didn't break something.