 So your biceps are bold, except when you bend down the elbows. Not a problem. In edit mode, click the bicep, shift D to duplicate, press enter, and make it a little smaller than the original. Name it, control C to copy the name, and make sure it's parented to the bicep. Go to object mode, click the mesh, go to vertex groups, find your bicep, double click, and control V to replace it with the name of your new control bone. Once you do this, you'll notice that the weight paint from the bicep has moved to our new bone. Now for the driver. Most rigs will look fine when you bend the arms forward, backwards, up, and down, but where most of them fall apart is when you try to move the elbow forward and down. An easy way to fix this is by rotating the correction bone during these poses. The trigger should activate when the arms are rotated forward and rotated down. In other words, both situations have to be true. The correction bones shouldn't rotate if they're only bending down, and they also shouldn't rotate if they're only bending forward. It needs to bend forward and down at the same time. So basically, we are going to have two triggers. The biceps X rotation and the bicep Z rotation. And the value we're going to control is our bone's Y rotation. To set this up, click the new bone, and under Y rotation, right click, add driver, set object to armature. Under bone, click your bicep, set type to X rotation, mode to quaternion, and space to local. OK, the first trigger is set. Time to set the second. Add input variable, transform channel, object to armature, set bone to your bicep, type to Z rotation, mode to quaternion, and space to local. And let's rename this variable to ZAR. OK, now that we have both triggers set, just type in our equation, you're done. Zero in the equation means that it will never rotate when the arm bends backwards. It'll only trigger when it bends forwards. VAR times 1.2 controls the rotation amount. You can control the rotation by making this number bigger or smaller. And ZAR times two is what limits the rotation so that it only twists when both triggers combine. All right, I hope that helps. If you enjoyed this video, please don't forget to like, subscribe, and ring that bell. I hope you have a fantastic day, and I'll see you around.