I wouldn't do it for long. It is an option to get an extra punch on your ball, "when nothing else works". From my experience it works fine, but over time it is very uncomfortable (you squeeze your little finger with the ball!), and, like REV-o-LUTIONS stated, it will harm your tendons if you push it too much! Be careful. But it is a good B-game option to have in store.
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DizzyFugu --- Reporting from Germany
"All that we see or seem, is but a dream within a dream..." - Edgar Allen Poe