Ankle prostheses and orthoses in academia

Building ankle prostheses and orthoses for patients who lost their lower limb or are missing gait functions due to neurological or muscular deficits has taken a large amount of research. This will be a brief overview over existing devices with short descriptions of principle and function. This list is not complete and will be updated.

Northwestern University2010"Net external energy of the biologic and prosthetic ankle during gait initiation"experimental study on gait initiation
SACH, Carbon Copy II, Seattle Lite, Quantum, Flex-FootRancho Los Amigos Medical Center1995"Energy expenditure during ambulation in dysvascular and traumatic below-knee amputees: a comparison of five prosthetic feet"comparative study of energy storing and releasing prostheses
SparkyWest Point / Arizona State2010"An active foot-ankle prosthesis with biomechanical energy regeneration"inverted pendulum,
80-100Nm, 170W motor output
Sparky3Arizona State2008" SPARKy 3: Design of an active robotic ankle prosthesis with two actuated degrees of freedom using regenerative kinetics"large size, large outline
Marquette University2012"Design of an active ankle-foot prosthesis utilizing a four-bar mechanism"four bar mechanism, based on Winter data
University of Washington2000theoretical work
Pantoe 1Peking University2010"PANTOE 1: Biomechanical design of powered ankle-foot prosthesis with compliant joints and segmented foot"monoarticular, 83W motor
iWalkMIT Media Lab 2007"Biomechanical design of a powered ankle-foot prosthesis"350W and 140Nm (required), serial and parallel compliance
Vanderbilt University2013"Preliminary evaluation of a walking controller for a powered ankle prosthesis"70Nm, 170W

“The advantages gained through the   addition   of   powered   actuators   are   always   coupled   with   an increase   in   size,   weight,   and   complex   control   systems.   These trade-offs played a large role throughout the design process of the prosthesis developed in this article.” (10.1115/1.4006436)

“[…] it is challenging to build an ankle-foot prosthesis that matches the size and weight of the human ankle, but still provides a sufficiently large instantaneous power output and torque to propel an amputee.” (10.1109/ICORR.2007.4428441)