Described here are prosthetic systems, devices, and methods of use therefor. Generally, a prosthesis may be configured to set a resistance to rotation of a prosthetic joint based on a phase of gait. The prosthesis may include a first cylinder, a first piston slidable within the first cylinder, a fluid sump, and a fluid circuit. The fluid circuit may include a plurality of interconnected fluid channels having a unidirectional variable-resistance valve and a set of check valves that are configured to provide unidirectional flow through the valve during piston compression and extension.

An assistance device is described to assist a joint motion of a lower limb. The assistance device includes a driving part, an elastic part, and a crank mechanism. The driving part includes a motor and a transmission mechanism to change a speed of the motor and converts a rotational motion of the motor into a linear motion. The elastic part includes at least: a series spring provided in series between the transmission mechanism and the crank mechanism, a first parallel spring provided between the driving part and the ankle part, and a second parallel spring provided between the ankle part and the foot part. The crank mechanism is provided between the driving part and the foot part and converts the linear motion to a rotational motion while changing a deceleration coefficient according to an ankle angle.

Powered limb prostheses with multi-stage transmissions are provided.

The ankle prosthesis of the present disclosure includes a load directing mechanism that alters the internal load path during weight bearing, guiding the load directly into the structural frame. By changing the load path with the load directing mechanism, both vertical and horizontal loads can be supported directly by the ankle's structure through a cam roller.

Prosthetic feet that allow for heel height adjustment and/or provide metatarsal joint functionality to more closely mimic natural human feet are provided. A prosthetic foot can include an ankle module having a locking mechanism configured to lock the heel at a particular height. The prosthetic foot can also include a toe region that adapts to varying heel heights. The ankle module and/or locking mechanism can be adjusted, controlled, and/or locked via a hydraulic mechanism. The toe region can curve upward relative to a portion of the foot proximal of the toe region.

A link assembly includes a main frame, a base link rotatably connected to the main frame, an input link rotatably connected to the main frame, and an output link at least 2-degree of freedom (DOF) rotatably connected to the main frame.

An ankle prosthesis is disclosed having an actuation system so as to act as a brake, modulated by motor means, proportional to the load stressing the prosthesis. The prosthesis is advantageously capable of reducing the work necessary to lift the prosthesis while maintaining an anthropometric encumbrance.

A unibody transtibial prosthetic device includes a socket personalized for a specific patient's residual limb. A pylon extends from the socket, the pylon being a unitary polymer structure of interconnected elongated supports having open spaces therebetween. The device also includes a foot-ankle complex, the foot-ankle complex being a unitary polymer extending from the pylon, the foot and ankle unitary structure being shaped to provide multi-axial dynamic flex to enable dorsiflexion, plantar flexion, inversion and eversion motion for smooth symmetric gait performance and energy capture and return. The socket, pylon and foot-ankle complex are portions of a unibody.

A prosthetic ankle includes a pair of prosthetic members movably coupled together to allow movement of the pair of prosthetic members with respect to one another. A hydraulic actuator or damper including hydraulic fluid in a hydraulic chamber is coupled to one of the pair of prosthetic members. A hydraulic piston is movably disposed in the hydraulic chamber and coupled to another of the pair of prosthetic members. A hydraulic flow channel is fluidly coupled between opposite sides of the chamber to allow hydraulic fluid to move between the opposite sides of the chamber as the hydraulic piston moves therein. A voice coil valve is coupled to the hydraulic flow channel to vary resistance to flow of hydraulic fluid through the flow channel, and thus movement of the piston in the chamber, and thus influencing a rate of movement of the pair of prosthetic members with respect to one another.

Knee orthoses or prostheses can be used to automatically, when appropriate, initiate a stand-up sequence based on the position of a person's knee with respect to the person's ankle while the person is in a seated position. When the knee is moved to a position that is forward of the ankle, at least one actuator of the orthosis or prosthesis is actuated to help raise the person from the seated position to a standing position.