User-Device Interaction Considerations and Testing of A Novel Orthotics for Restoration of Natural Physiological Gait

When developing orthotics, a major concern is wearability. Wearability is defined as the interaction between the human body and the wearable object. In case of orthotics, the definition extends to include the effects of the human body in motion, or Dynamic Wearability. Major concerns include matching and obtaining close alignment between the structure of the exoskeleton to the wearer, affectation of the biomechanics of locomotion due to added mass and inertia of the device itself as well as the additional kinematic constraints inadvertently imposed on the wearer. Portability and stability are three other major factors that need to be considered. Portable orthotic devices can be used as a part of the wearers everyday life without the need for constant medical supervision that would limit the application of orthotic to clinical settings.In this paper the user-device interaction considerations, manufacturing and testing of a recently designed passively actuated hand free orthotic device is presented. The six-bar device is designed to coordinate the motion of both knee and ankle joints simultaneously that mimics the natural walking gait. Test results from comparing the subject¢‚¬„¢s walking on the ground with and without the orthotic device show only about 3.93% difference in stride length. It is also clear that the toe trajectory is sufficiently close to the experimental trajectory (within ‚±9.6% root-mean-square deviation calculated) to guarantee natural motion of the supported leg