Watch the Lesson 4: Thumb Bounce online guitar lesson by Stu Hamm from Funk Bass for Beginners
As the figures you play with your thumb start to get faster, you'll need to work on getting a controlled bounce of your thumb. Learning to bounce the thumb off the string is a great way to prevent injury in your arm, wrist or hand. If you force it, you can hurt yourself. So as we work through the upcoming exercises, try to always keep a relaxed approach in the muscles of your arm and be careful to work on getting a nice loose bounce off the strings, similar to when a drummer does a press-roll on his snare drum.