A prosthetic knee having a passive knee locking mechanism that uses the same four-bar mechanics found in a natural knee. The flexible four-bar mechanism guides the motion of the knee, aids in the return of the knee from full flexion to extension, and connects a femoral gear to a tibial gear. The gears have a circular radius and are connected using parallel links to keep the femur and tibia together when the knee is active. The knee stays locked throughout the stance phase. At toe off, no weight is applied on the prosthetic knee allowing the knee to flex. The flexible links are stretched, thereby increasing the stiffness in the springs, and at terminal swing phase, moments before heel strike, the flexible links in the four-bar mechanism snap back to the extended/locking position and lockout once the user applies his/her weight on the knee.

A prosthetic knee joint includes an upper part, a lower part which is arranged pivotably to the upper part, a fastening device arranged on the upper part for a proximal prosthetic element, a fastening device arranged on the lower part for a distal prosthetic element, a four-limbed joint system with four linkages articulatedly fastened to each other, which are each pivotable to each other around a pivot axis, wherein the upper part is arranged on the joint system. The joint system may be mounted pivotably on the lower part from a starting position counter to a spring force during a stance phase flexion, and the action line of the spring force may be aligned such that a moment acting against an inflexion of the joint system is present.

A prosthetic ankle module allows for translational and/or rotational movement of a prosthetic foot relative to an adapter. The ankle module can include a four-bar linkage assembly. Links of the linkage assembly can be arranged in various configurations, e.g., parallel or non-parallel and having equal or non-equal lengths, to provide different functions and benefits, e.g., dorsiflexion, plantar flexion, vertical shock absorption, inversion, eversion, and/or rotation about the sagittal axis. Other types of linkage assemblies are also possible. A prosthetic foot can further include a support spring to limit the range of motion of the adapter in use.

Exemplary embodiments herein relate to a unique 4-bar linkage transmission provided between two adjacent links of a powered augmentation device that provides a varying mechanical advantage. Due to the kinematics of the linkage, the mechanical advantage between the actuator and the augmented joint varies with the position of the linkage. Thus, a high mechanical advantage can be provided in positions at which relatively high joint torque is required, and low mechanical advantage in positions at which relatively high joint speed is required. Consequently, the speed-torque (or velocity-force) operating area of the actuator can be consolidated by mapping the widespread output regions onto a smaller input region. This allows the actuator to be optimized for a narrower range of usage.

An artificial knee is configured to be worn by a person. Artificial knees include a thigh link configured to move in unison with a thigh of the person, and a shank link configured to be coupled to the thigh link. Artificial knees include a compression spring coupled to the thigh link at a first end of the compression spring, the compression spring configured to be coupled to the shank link at a second end of the compression spring. The compression spring is configured to provide an extension torque between the thigh link and the shank link during a first range of motion of the thigh link and the shank link relative to each other. The compression spring is configured to provide a flexion torque between the thigh link and the shank link during a second range of motion of the thigh link and the shank link relative to each other.

A prosthetic knee joint includes an upper part, a lower part which is arranged pivotably to the upper part, a fastening device arranged on the upper part for a proximal prosthetic element, a fastening device arranged on the lower part for a distal prosthetic element, a four-limbed joint system with four linkages articulatedly fastened to each other, which are each pivotable to each other around a pivot axis, wherein the upper part (10) is arranged on the joint system. The joint system may be mounted pivotably on the lower part from a starting position counter to a spring force during a stance phase flexion, and the action line of the spring force may be aligned such that a moment acting against an inflexion of the joint system is present.

The invention relates to a prosthetic joint which can be used as an artificial knee. Said prosthetic joint consists of a knee upper part (1), a knee lower part (2) and a fixing element (8) connecting said two lower parts. The knee upper part is rotationally arranged about the rotational axis (4) of the fixing element and rotation occurs counter to the force of an elastic element (17) which is arranged in knee lower part. Detachable fixing means (7), which are used to fix at least one rotational position, are provided between the knee upper part and the fixing element.

A multi-articulated link knee joint includes: a knee unit in which an upper link unit rotates relative to a lower link unit by a multi-articulated link mechanism including a plurality of link units including the upper link unit and the lower link unit; a relative position detector for detecting a relative position of the upper link unit relative to the lower link unit; and an angle detector for obtaining a bending angle of the knee unit from the detected relative position.

A device includes a first member and a second member disposed in series along a longitudinal axis. The device also includes links coupling first joints of the first member to second joints of the second member. The first and second members and the links arranged to define a planar parallelogram linkage. The devices also include a resilient element disposed between the first member and the second member, the first member and the second member preloaded against the resilient element. The first member and the second member are preloaded to provide an arrangement of the first and the second joints in which a motion of the first joints with respect to the second joints is constrained to a direction substantially parallel to the longitudinal axis. The devices further include a sensor for generating a signal indicating a separation between the first member and the second member.

The present disclosure describes transmission systems for use in artificial joints of assistive devices, such as assistive prostheses, orthoses, and powered exoskeletons. A variable transmission is configured to automatically or manually adapt the torque profile to the demand of different locomotion tasks, such as a relatively high torque and low speed profile for a task such as standing up or ascending stairs, or a relatively low torque and high speed profile for a task such as walking.