There are many different methods of supporting tomato plants. You can tie them up on strings, cage them, train them up a ladder, twist them up a pretty colored spiral stake or put them through hog panels. One thing all of these methods have in common is that you have to keep up with them every day. You have to make sure your leaders stays in the frame, and any side shoots that you do not prune off need to be woven in as well or at least tied to the outside.
If you don't your supports will be useless. In fact, in this case I think having the ladder is actually doing more damage to the plant than letting it sprawl on the ground because now the side branches are broken over a rail resulting in the stem snapping.
Here is one of my own determinate varieties, unpruned,
but still contained within the ladder.
There are soft tomato ties here and there supporting side branches.
Sometimes the tie needs to be repositioned to support the fruit as they grow.
And here is an indeterminate variety, well pruned
to a single leader and contained in the ladder.
Sometimes the branch will lay harmlessly along the ground.
But the worst case scenario is the branch will break off entirely and you will lose all the fruit on it.
So maintain your tomatoes! You don't want all your hard work and hopes dashed because you didn't keep up on simple maintenance.