The close-force sensitivity setting allows you to adjust the force that the garage door opener uses to open or close your door. This functions as a safety feature that tells the opener to stop if there is something in the path. If you notice that your door exerts too much or inadequate force while closing, then the force sensitivity setting needs to be adjusted.
Before making the adjustments, make sure to disconnect the power supply to your garage door opener. Examine the close-force sensitivity adjustment screw, and look at what it says in there. It should indicate which direction you should turn the screw in order to increase or reduce the force used to close the door. Do not confuse the close-force adjustment screws with the limit adjustment screws. The limit adjustment screws are always larger than sensitivity screws.
If you are not completely confident that your garage door operates safely and reliably, it is a good idea to have it checked by a professional garage door repairperson.