Knee-Ankle-Foot-Orthoses (KAFO) braces assist patients with limited lowerextremity functionto stand by holding the knee extended and the ankle neutral. Although thebrace aids users inmaintaining a standing posture； rising from a chair, while wearing a KAFO,becomes asignificant challenge as these movements require substantial upper bodystrength to hoist oneselffrom seated position. The sit-to-stand (STS) biomechanics of 10 healthysubjects were analyzedusing motion capture analysis and inverse dynamics. The results of thisanalysis were utilized inthe design and manufacturing of an assistive STS KAFO prototype. The currentprototypemechanically generates a knee extensor moment and allows for a flexed kneeduring STS.Therefore, the prototype will allow for reduced upper body demand to be placedon the patient.Kinematic calculations suggest the current prototype has the potential tosuccessfully assist a 90kg KAFO user. The ability for the assistive device to meet the torque demandsof KAFOdependent users will be investigated further in future clinic-based testing.Furthermore, reducingsize and weight will become a priority in future prototypes. However, based onthe results todate it can be soundly predicted that the KAFO devices proposed here may beutilized by a widespectrum of users.
