Instrumented and active exoskeletons for human anatomical joints: Design methodology and applications

This paper addresses the design of instrumented single joint and multi-joints active orthoses for musculoskeletal and neuromuscular disorder exploration and functional rehabilitation. The use of these multi-contact exoskeletons, operating a selective limb joint mobilization, allows the measurement and the control of physiological parameters (instantaneous helical axis (IHA) motion, joint motion and torque) of each individual anatomical joint. Passive joints have to be added into the kinematic chain of the exoskeleton in order to eliminate residual stresses in limb/orthose interaction due to misalignment between the device principal axis of rotation and the IHA of the anatomical joint. The kinematic design and the control of spatial orthotic mechanisms to obtain an adaptation and a best-fit to the joints kinematics are discussed afterward. Examples of active orthosis design for knee, elbow joint and lower limbs are also given.