EBSpro knee joint, polycentric, with hydraulic swing phase control

How does the EBSpro work? The mechanical principle of the EBSpro is based on the proven 3R60 prosthetic joint. The polycentric prosthetic joint has five axes that are arranged to form a ring. The anterior axis chain is designed like a conventional four-axis joint, but the posterior linkage bar is interrupted by an additional pivot point (Fig. 1). The proven design thus allows for two different modes of operation: swing phase mode and stance phase flexion mode. Two specially configured miniature hydraulic units (Fig. 2, A+B) control the two modes. Outstanding performance during the stance phase is the key feature of the 3R60. The spring and hydraulics combination in stance phase flexion mode is individually adjustable and can be precisely adapted to suit the requirements of the prosthesis wearer. Thanks to the progressive nature of the EBS resistance – realised with an auto-adaptive EBS unit – the effect can adapt itself over a large range of walking speeds for the first time. The higher the walking speed, the greater the extent to which flexion is limited. The lower the walking speed, the less damping resistance takes effect. This ensures greater stance phase flexion (Fig. 3). In this way, this important function adapts to various everyday situations. For the prosthesis wearer, this means enhanced safety and comfort as well as a highly natural gait pattern.