Use the Edit menu > Grid Options command to access subcommands for the following:
Glue Joints To Grids. Use the Edit menu > Grid Options > Glue Joints to Grids command to "glue" joints along a grid line to the grid line so that if the grid line is moved, the joints move with it. Frame and shell objects that are attached to the joint objects when it is moved remain attached to the joint object and thus move or resize as appropriate. The command is a toggle.
Lock Onscreen Grid System Edit. Use the Edit menu > Grid Options > Lock Onscreen Grid System Edit command to enable or disable onscreen editing/movement of general grids.