A multi-fit orthotic structure including an attachment system for coupling the orthotic structure to a wide variety of subjects without requiring a custom fit. In one embodiment, active mobility assistance is provided via an orthotic system capable of integrating a linear actuator and linkage system to deliver torque to the lower leg of a subject to facilitate flexion and/or extension motion of the subject's leg. The orthotic structure is attached to the subject using a textile suspension system which does not require the orthotic structure to interface directly in the knee region or at the lateral areas of the thigh and calf of the subject, thus providing an ideal fit for the widest possible range of subjects with the minimum number of required sizes.