One of the things I dislike about getting old is losing elasticity. There's nothing much you can do about it; even spending all day at the gym won't stop muscles from becoming less springy and vital (I haven't actually tried this, but I suspect it's the case). Things just wear out, and you kinda have to get over it, I guess.
I remember seeing the fourth in the Indiana Jones series of movies - which was made much later than the others, at the time Harrison Ford was around 65 or 66 - and noting that when he was required to leap upwards from one crate to another, he plainly found it difficult. Why they didn't use a double I don't know, since he was seen from the back at that point, as I recall. But I sympathised with him not a little.
Recovering your balance is part of this issue. A while ago my wife and I (and the dog) went for a walk and found ourselves, somewhat by accident, walking alongside the railway track at Caversham. The path, such as it was, was fairly rough, overgrown and brambly. We decided, on hearing the train coming along the track, that it might be wise to move up the bank and away from the tracks. I headed up first, full of my usual youthful confidence, grabbed at a bush to haul myself up, missed my hold, tumbled backwards down the slope, with my head towards the tracks. It wasn't that I was in any danger of being run over, but it was embarrassing being seen sliding headfirst down an easily-climbed slope by a trainful of passengers. My wife was more concerned than I was; I hadn't actually done any damage to anything except my dignity. It didn't help that I was trying to hold the dog's lead at the same time, and wasn't sure where he'd got to in the melee.
What was painful to discover, however, was the fact that I just didn't have the means to avert the fall. In the past, once I'd lost my grip on the bush, I would have saved myself from falling by swivelling my body around, or doing some other adjusting manoeuvre [manoeuvre isn't a word I can ever spell easily]. That just didn't happen.
Yesterday, while I was out weeding the garden, I banged my head on one of the struts that support one of the two heat pump machines we've got outside. Why these struts have to stick out and catch unwary elderly people I don't know - it's not the first time I've been caught. Fortunately I had my hat on and that saved any really serious damage. I think.
The problem was that instead of reacting by stepping backwards without any problem - except that of saying Ouch or something equivalent - I toppled backwards, couldn't recover my balance, and fell into a gooseberry bush. Yup, a gooseberry bush, which obliged me by prickling me wherever it could. In the past I wouldn't have come into contact with the bush, and I wouldn't have yet again lost my sense of dignity (not that anyone else was around). But for some reason known only to my legs, they just gave up the fight and dropped me in a heap. Very unfriendly of them, though perhaps the fact that I've been running and walking on them for nearly 70 years has something to do with it.
One could offer the advice: don't grow old. However, like it or not, I have, and plainly I'm going to have to work out ways to avoid sliding, falling, banging my head or otherwise damaging myself. May take a bit of effort.