A lower limb prosthesis comprising an ankle unit having a combination of an hydraulic piston and cylinder assembly providing a continuously damped range of ankle flexion, and a resilient telescopic shock absorber in a shin part. The damping resistance of the piston and cylinder assembly is the predominant resistance to ankle flexion and is provided by a piston 28 which is axially moveable in a cylinder 26 centred on the shin axis, with the hydraulic fluid forced through one-way valves 36, 38. The wall 26W of the cylinder has a cylindrical outer bearing surface for a sleeve 48, which is translationally displaceable relative to the piston and cylinder assembly according to the axial load, the sleeve being resiliently mounted by a compression spring 52 which extends axially within the sleeve and has an integral end portion 52B forming an upper bulkhead of the cylinder. The sleeve is also rotatable on the cylinder wall, the spring 52 providing torsional resistance.
