A high performance, low-cost passive prosthetic knee includes one or more modules to enable able-bodied gait by transfemoral amputees to improve metabolic efficiency and reduce stigma from conspicuous abnormal gaits. A stance stability module includes a latch with a virtual lock axis that automatically locks and unlocks. An early stance flexion module enables able-bodied gait during stance. Hydraulic fluid dampers ensure reliable swing phase control. A swing extension energy storage module stores and returns energy as the knee locks and unlocks, respectively. These modules may be used together, in any combination, or individually.

Artificial limbs and joints that behave like biological limbs and joints employ a synthetic actuator which consumes negligible power when exerting zero force, consumes negligible power when outputting force at constant length (isometric) and while performing dissipative, nonconservative work, is capable of independently engaging flexion and extension tendon-like, series springs, is capable of independently varying joint position and stiffness, and exploits series elasticity for mechanical power amplification.

A method for controlling an artificial knee joint comprising an upper part and a lower part pivotally connected to each other, a resistance unit arranged between the upper part and the lower part and having an adjusting device to adjust the damping resistance, a control unit, the adjustment taking place on the basis of sensor data from at least one sensor. During the swing phase at least one of the knee angle (KA), the knee angle velocity (KAV), the knee angle acceleration (KAA), the lower limb angle, the lower limb velocity, the lower limb acceleration, the ankle moment (AM) and the axial force (AF) is sensed, the curve of the parameter is determined and the damping resistance is changed when, after an extreme value of the parameter is reached, the monotonic behavior of the curve of the parameter changes within the swing phase.

A prosthetic knee joint includes a thigh connection part to be positioned near a thigh part, a lower leg part rotatibly coupled to the thigh connection part, and a power generating, part for generating power using a resistance resulting from rotation of the lower leg part relative to the thigh connection part.

An actuator-damper unit for use in orthotic or prosthetic devices. The actuator-damper unit includes a housing which may be fastened on the orthotic or prosthetic device and in which a cylinder is formed. A first piston is displaceably mounted in the cylinder and is coupled to a piston rod. The piston rod is disposed, via a first end, on the first piston and may be coupled, via a second end, to the orthotic or prosthetic device. The first piston separates two fluid chambers in the cylinder from each other and forms a piston-cylinder unit, wherein at least one further piston is coupled to the first piston in order to form at least one further, variable-volume fluid chamber.

A prosthetic knee includes a hydraulic resistance system with an extension hydraulic circuit and a flexion hydraulic circuit. The flexion hydraulic circuit includes a switchable resistance assembly with a mechanical switch. The mechanical switch has an engaged position and a released position. The switchable resistance assembly provides a first level of hydraulic resistance when the mechanical switch is in the released position and a second level of hydraulic resistance when the mechanical switch is in the engaged position, the second level being less than the first level. The mechanical switch moves to the engaged position when the hydraulic resistance element reaches a predetermined extension position and moves back to the released position when fluid flow falls below a predetermined threshold.

A joint device with an upper part and a lower part which are mounted on each other so as to be pivotable about a pivot axis, a hydraulic unit secured on the upper part and the lower part, and a housing in which a cylinder is arranged. A working piston is arranged in the cylinder and is coupled to at least one spring mechanism which transmits tensile forces and compressive forces and which engages on at least one abutment arranged displaceably inside the cylinder.

The present invention relates to a foot prosthesis (1, 61) comprising a heel (6, 71) and a tip (7, 62), both of which can bear on the ground, and an ankle support (2, 67), characterised in that the prosthesis also comprises at least one damping element (10, 76) designed to be at a distance from the ground.

Technology is described to provide a foot/ankle prosthesis for individuals with transfemoral limb loss. This technology is able to store and release energy and thus individuals or patients who are using the foot/ankle prosthesis are able to expend less energy when walking or running. The device or system can include a prosthetic foot/ankle system with a linear or rotary hydraulic damper such that the hydraulic damper is attached to dynamic energy storing spring elements. The axis of rotation of the system can be near to that of an intact human ankle. The system can utilize spring elements based on the vertical displacement of the center of pressure of an intact normal foot. The system can also provide user adjustable heel height.

Technology is described to provide a locking device to control movement of a prosthetic limb. The technology may include a hydraulic damper having a movable damper wall in a hydraulic housing of the hydraulic damper, and the movable damper wall may form a first chamber and second chamber in the hydraulic damper. A first fluid channel may be coupled to the first chamber. In addition, a latch may be in fluid communication with the first fluid channel. A poppet valve can be configured to set the latch in an open position when pressure is reduced in the first chamber and to stop fluid movement when pressure is increased in the first chamber. A second fluid channel between the second chamber and the latch may enable fluid to flow between the second chamber and the latch.