Locking prosthetic knee and core components therefor

A prosthetic knee, comprising:

• an elongate frame configured to house electronics;
• a magnetorheological (MR) fluid actuator movably coupled to a proximal portion of the elongate frame, the actuator being rotatable in an anterior-posterior direction about a medial-lateral axis, the actuator comprising an outer spline and a core assembly, the core assembly comprising:
• a screw member comprising a head portion and a shank portion extending from the head portion, a first end of the shank portion being attached to the head portion, and a second end of the shank comprising a threaded portion;
• a nut member comprising a complementary threaded portion configured to engage with the threaded portion of the shank;
• a coil;
• a plurality of annular blades disposed around the shank and held by and between the head portion and the nut member;
• a proximal connector coupled to the outer spline and configured to rotate with the outer spline about the medial-lateral axis;
• and
• a distal connector coupled to a distal end of the elongate frame,
• wherein a torsional resistance of the actuator to rotation about the medial-lateral axis varies based on a magnitude of a magnetic field applied by the coil to the magnetorheological fluid to vary a viscosity of the MR fluid in the actuator.