How to make characteristics align vertically

Can someone help me to work out how to align characteristics in the product display page vertically rather the the default horizontal? In my case its a range of sizes.

Solved this myself!
1. Go to the Characteristics edit screen
2. Edit the value(s) of the characteristic
3. At the end of the 'name' field add '<br />'
4. If your using other languages, add the same to the name field on each language tab.

Note: Adding '<br />' to the name field in the 'Main Information' tab dosen't seem to get saved - Nicolas?

You will have to change the code:
$element->$column = strip_tags($value);

to:
$safeHtmlFilter = & JFilterInput::getInstance(null, null, 1, 1);
$element->$column = $safeHtmlFilter->clean($value, 'string');

in the file administrator/components/com_hikashop/classes/characteristic.php

A more elegant solutions is to use CSS:

This does not affect the product title as the embedded <br /> does and no core code changed

Thank you for that solution, I'm sure it will help others.