A biomechanical control mechanism for correction of clubfoot deformity in babies

Abstract

A novel mechanism for an ankle-foot orthosis (AFO) based on a passive four-bar linkage for non-surgical treatment of clubfoot disorder is proposed. Clubfoot is a historical foot deformity where foot turned in and pointed down causing the subject to walk on the outside edges of foot. The non-surgical correction of this deformity is an unsolved challenging problem in medical domain. An AFO is a device for correction of foot deformities such as clubfoot in this case. A mechanism is proposed that when fitted to AFO, control the motion of the abnormal foot during correction. The linkage is attached to the foot and shank of the AFO. As the fly nut is rotated the downward force will be transmitted to the forefoot region to dorsiflex the clubfoot and correct this deformity. The magnitude of the force can be controlled by number of rotation of the fly nut. The initial wearable prototype has been proposed and is ready for fabrication and testing on test subjects to demonstrate the feasibility of the concept.