It is a good technique, I've done several martial arts before so stretched like this, it is hard to get pressure over the legs without leaning forward though.Gary
And don't stretch before climbing, esp. not forearms/upper body. There are studies showing that stretching temporarily weakens the stretched muscles. Stretch at the end of a session as part of your warm down, or in separate sessions.
Maybe have a read of Feehally's Flexi Madness on Beastmaker.co.uk. I can't think of a better person to take stretching advice from.
I noticed a big difference when I stopped pre climbing stretching especially on injuries.
As previously mentioned http://ukbouldering.com/board/Smileys/ukbCustom/icon_agree.gif Don't stretch before climbing BUT warm up with lots of dynamic movements - swinging etc. I noticed a big difference when I stopped pre climbing stretching especially on injuries.General post climbing stretching from moon climbing:http://usa.moonclimbing.com/stretches-lower-body-c-334_349.htmlBeastmaker stretching mentioned above.http://www.beastmaker.co.uk/Stretching.pdfSome sport injury stuff for good measure.http://www.sportsinjuryclinic.net/cybertherapist/back/hamstrings/tighthams/hastringstretches.php
Shades of grey, >= 60 seconds results in decreased performance, whilst <= 45seconds doesn't appear to.