My understanding is that this arrowhead is not supposed to tell that the hands are in contact, but to be used when the paths overlap, so that you cannot write two arrows because they would be on top of each other.
Personally, I tend to use it when the hands are one unit, even if not in touch. In NSL, at least one two-handed classifier exists, and for that I use the both-hands arrow, regardless of which path this classifier-unit moves.
> Date: Fri, 24 Feb 2012 06:40:06 -0500
> From: [log in to unmask]
> Subject: Re: both-hand arrow
> To: [log in to unmask]
> I'm constantly wanting to use it to show both hands travelling in same
> direction, even when not in contact -- it crops up just often enough
> in ASL that this shortcut really is useful!
> I transcribe a lot of ASL when preparing to interpret vocal concerts
> (ca 20 songs per year) but have had little time to prepare these texts
> for online showing off, alas.
> Kim from Boston
> On 2/24/12, Honza <[log in to unmask]
> > Hello Val,
> > somehow we started using "both-hand" arrow always when both hands makes the
> > same movement, but now, when I look back to your lessons, I see it should
> > be used only when hands are in contact.
> > I also searched SignPuddle and there I found also several writings, where
> > this arrow is used in "my way".
> > Should it be used this way, or better only in origin way, for hands in
> > contact?
> > thanks
> > Honza