Gait analysis with a multi-segment foot model for the biomechanical validation of hinged foot-ankle orthoses

Hinged Ankle Foot Orthoses (HAFO) are largely prescribed for the treatment of ankle joint deficits, within a variety of neurological and orthopedic disorders. These are intended to control motion of this joint, to compensate for weakness, to correct deformities or to reduce mobility in the sagittal plane only. Quantitative assessment of their functional efficacy is still very limited. The aim of this study is to assess by means of state-of-the-art gait analysis the effect of the position of the mechanical axis of rotation in unlocked HAFO. Unfortunately, in routine custom-made manufacturing, this axis of rotation is positioned exactly mediolaterally, and also a few centimeters above the malleoli, very far from the intermalleolar physiological location.Apossible better axis location for more physiological foot joint rotations was sought by looking at multi-segment foot kinematics.