Hydraulic prosthetic ankle

A prosthetic device comprising:

• a foot portion;
• and
• an ankle portion coupled to the foot portion, the ankle portion comprising:
• a hydraulic cylinder, the hydraulic cylinder comprising a first chamber, a second chamber, and a piston separating the first chamber and the second chamber, the first chamber and the second chamber filled with a hydraulic fluid,
• a first valve disposed along a first passage, the first passage and the first valve allowing dampened fluid flow between the first chamber and the second chamber during plantarflexion,
• a second valve disposed along a second passage, the second passage and the second valve allowing dampened fluid flow between the first chamber and the second chamber during dorsiflexion, and
• a diverter valve being in selective communication with the second passage and a third passage, a third valve disposed along the third passage, the third passage and the third valve allowing flow between the first chamber and the second chamber during dorsiflexion in a swing phase of gait, wherein a dampening resistance on the flow through the third passage is lower than a dampening resistance on the flow through the second passage,
• wherein the diverter valve diverts the flow from the second passage to the third passage based on a system status, and
• wherein an orientation of a top portion of the ankle portion is configured to change based at least in part on a position of the piston within the hydraulic cylinder.