What does forearm to extend mean?

Forearm to extend means your arm is getting longer by moving from bent to straight.

Imagine you're playing with a toy car. When you bend your arm at the elbow, it’s like pressing the button to make the car go vroom, short and fast. But when you extend your forearm, you’re like letting the car zoom out of the garage, long and smooth.

Think about opening a door. When your arm is bent, it's like the door is halfway open. But when you extend your forearm, straightening your elbow, it’s like pushing that door all the way open. Your arm gets longer, just like the door gets wider.

If you're reaching for a cookie on the top shelf, you might start with your arm bent. Then, as you pull it up, you extend your forearm, making your reach go from short to long, so you can grab that tasty treat!