Tumbling / Cascading / Trailing / Hanging Basket tomato question

[Hatgirl]

What is a Tumbling / Cascading / Trailing tomato?

I mean, I know what they are. They're the type I grow in a hanging basket, with names like "Tumbling Tom" and "Cherry Cascade". But what are they?

Determinate or Indeterminate or either? A type of dwarf or something else? Why is their growth so compact but so sprawl-y, unlike most determinates? Is the gene(s) that causes this plant trait known?

[KarenO]

Hi, they are small determinate or semi determinate cherries with a lax stem habit that in a hanging basket or window box allows them to drape or "tumble " over the sides of the container. With support, such as a small cage they can be grown upright in a bed or planter as well
Karen

[Hatgirl]

Yes, but what is a "lax stem habit"? Determinate tomato plants (spsp) are ones where the normal unending "shoot grows 3 leaves and then a flowering truss, new shoot grows 3 leaves and then a flowering truss, new shoot..." cycle has been disrupted so that each new shoot produces few and fewer leaves until it finally produces only two flowering trusses and no new shoot, and so no longer grows "up".

So what's the biology behind a cascading tomato stem? Does anyone know?