I know click, scroll and keyboard. The easiest and best one is use the : Z, X ,C keys, because Z Contract/extend, X hold and relax ( the joint of u're with the mouse), and C relax/hold all your pieces. Calculating, when you click 3 times do extend, you just click 1 time on keyboard to the same thing.

I scroll, because I memorized the way each joint contracts/extends when I do it. It's like the Z button, but imagine only pressing it once and it knows which way you want it to go. It's a lot faster.