Golfers who ride in golf carts are always driving here and there from one ball to the other, taking up a lot of time. If the rule is in effect that the cart is not allowed to leave the path, golfers are inclined to dawdle over club selection and make unnecessary trips back and forth from the ball to the bag. Walking keeps senior golfers' legs strong, and strong legs make for a more powerful swing.
For those of us reaching the back 9 of their lives it's important that the left heel comes off the ground in the backswing. Let it come up and the left arm bend for the sake of a longer, freer swing. Many golf coaches demand that their students keep the left heel on the ground. However, l don't fully agree with this practice, because one of the important factors in an older golfer's swing is the body turn. Keeping the left heel down makes it all the harder to do this, so just let it come up as it will want to do.
A straight left arm inhibits the turn if you're getting on a bit. If a senior golfer has become heavy around the chest and stomach, there should be no effort made to keep a straight left arm at the top of the backswing. A player should try to swing longer, not shorter, as the years go by.
Out of Bounds: Meddling in other people's golf games, is how some avoid dealing with their own.