A linear hydraulic motor (12) includes an elongate cylinder (26) and at least one piston (34) slidingly located inside the cylinder. The piston (34) has a longitudinally extending portion which fits with clearance in the cylinder and which describes a path in use which penetrates an interior zone of the cylinder which extends radially inwardly from an aperture in the cylinder wall. An internal reinforcing member (300) is slidingly located inside the cylinder to travel with the piston. The reinforcing member describes a path in use which also penetrates said interior zone of the cylinder which extends radially inwardly from the aperture in the cylinder wall and the reinforcing member has portions which are concentric and radially aligned with circumferentially spaced portions of the cylinder wall that are on opposite sides of said aperture in the cylinder wall.