Use your fingers to dig. Build up your strength in even the smallest muscles, then gradually, work up through your hands to your arms.
13 seconds sound clip from the The Woman Avenger (1980) movie soundboard.
You can hear this line at 00:08:25 in the DVD version of the movie.
Quote context
[...]
- The Dragon Fist is hard to learn, and it will hurt. You have to suffer first to succeed.
- That's a small price to pay. I can take it. After all that I have gone through...
- Lord Buddha was smiling the day that I met you. You can stay here with me, my girl.
- The first position is the attack. You must strengthen your arms and hands.
- The palm of your hand can break bamboo branches.
- You mustn't forget to strengthen your legs. Practice carrying water up and down.
- Your legs are the root of the tree. Don't forget, you must keep them strong.
[...]