You're asking and I'm answering.
"Fit, whenever I am reading about how to do a new exercise it almost always says, "Do not lock your knees," or elbows or whatever. Why is locking so bad?"
- Locked Lindsay
That's a very good question! Let me start with a little explanation. Locking your joints is when you are doing an exercise and you fully extend the limb until it can't straighten anymore — it sort of "locks" in place. The problem with locking your joints (knee, elbow, etc.) while lifting weights is that it places an enormous amount of stress on the joint and off the muscles, which can lead to joint problems and/or injury. Furthermore, since locking your joints gives your muscles a rest mid-movement, it makes for a far less effective exercise than if you kept a slight bend in your joints. I don't know about you, but I am looking to get the most out of my time at the gym so it is definitely wise to always keep a slight bend in the arms and legs.
I always like to use the jumping analogy. Would you ever jump up and land without bending your knees a little bit? No. Instinctively you bend them because it is the best way to deal with resistance and avoid injury. Think of this when trying to remind yourself not to lock them.