"The hook grip can be tricky initially, especially for individuals with smaller hands, and even more so for those smaller handed individuals whose hands are also thick. The short answer is: Make it work. There's a reason that every weightlifter in the world uses the hook grip, and that's simply that when you're accelerating a barbell as you do in the snatch and clean, you cannot maintain your grip without it.
When you start feeling sorry for yourself, just remember that there are 56 kg (124 lb) men who snatch and clean with the hook grip on the same 28 mm barbell that the rest of us use. Halil Mutlu snatched 138 kg at 56 kg. If someone with hands that small can hold onto a weight that big with a snatch grip, you can find a way to manage."
"For most people, there is some stretching that needs to occur before the hook grip feels really secure. The best way to accomplish this is to simply use the hook grip every time you're pulling a bar. Your thumbs will stretch out a bit and your hands will become conditioned to the position, and it will eventually start feeling much more comfortable. "
http://www.catalystathletics.com/blo...hp?blogID=1671