I use velcro wraps to hold the coiled cords to the arms at the main quick-release joint and at each ball joint / elbow (including just below the strobe head). I do NOT "tie down" the junction anywhere. Like you said, that seems to threaten stretching or bending too close to the main connection to the housing. With the velcro ties kind of tight so they hold down into one particular coil of the cord, the junction ends up "suspended" pretty well. So it's still under a little tension, but at least the tension is pretty symmetrical.
The velcro cord wraps are nice because you can find them at hardware stores (Home Depot for us in the states, not sure about down under) vs. having to special order, they come in a pretty big ring of them for not too much, they're reusable (unlike tie wraps) and don't require cutting off to disassemble (unlike tie wraps), and I don't worry that they're so 'strong' they'd wear on the cord itself (also like tie wraps might, if you had one rubbing edge-on to your cord insulation for a long time).
Here's an example link to the velcro wraps:
http://search.live.com/products/50-Pack-8-...%20ties&p1=[CommerceService+scenario%3d%22o%22+docid%3d%22235DFB6AC3A9D7A2FB72%22+p%3d%22df5c7f1ba4404c05b3f423c4e307eee6%22]&wf=Commerce&FORM=EGCL