I used to have posts on BT about the combination.

here's a pdf I found -
http://rheumatology.oxfordjournals.o...t/37/4/382.pdf

http://rheumatology.oxfordjournals.o...act/34/12/1157

and some books turned up- they might be in libraries-
http://books.google.com/books?id=BpA...gaqzo#PPA23,M1

http://books.google.com/books?id=OQh...XxxzyqSpkbgIRs

http://hypermobility.org/beighton.php

If they think logically about it they should be able to realize how lax joints/tissues could easily contribute to overuse use syndromes and postural instability.
It was explained simply to me - the muscles have to work much harder to stabilize the bones and joints during use and static postures.

Most likely not the only cause of it - but a factor in the cause of RSI & TOS