An aircraft landing gear assembly comprising: an axle having an axis, a wheel rotatably mounted on the axle to rotate about the axis, a brake arranged to selectively exert a braking torque on the wheel about the axis, a brake anchor structure having a substantially fixed position relative to the axle, a brake reaction linkage that mechanically couples the brake to the brake anchor structure, and a sensor comprising a sensor element arranged to detect a change in one or more physical properties of a component of the brake reaction linkage in order to determine a stress in the component due to the braking torque, wherein the sensor element does not contact the component.