A system for measuring displacements of a blade root of a rotor blade of a wind turbine includes a hub, and a rotor blade coupled to the hub by a pitch bearing. The system further comprises a reference plane and at least one displacement sensor. The reference plane is configured to move with the rotor blade as the rotor blade moves relative to the hub while the displacement sensor is fixed to the hub and the displacement sensor is configured to detect a displacement of the reference plane relative to the hub without physical contact. Alternatively, the reference plane has a fixed position with respect to the hub while the displacement sensor is fixed to the rotor blade and the displacement sensor is configured to detect a displacement of the reference plane relative to the rotor blade without physical contact.