Has anyone else experienced trouble locking the Lower Arm bone to the appropriate axis? Extrude bone, then Shift + (appropriate axis), right? In an attempt to figure out what I was doing wrong, I extruded the second bone from the Stem Bone, and systematically tried x, y and z axis respectively, and parented Lower Arm to second bone…yet the Lower Arm is free to move in any axis when in Pose Mode.
Note: I applied the Mirror Modifier making the Lower Arm a single mesh.