A device designed to measure the mechanical properties of the clubfoot deformity is described. The mechanical properties are viscoelastic parameters manifest in passive torque versus range-of-motion measurement at the ankle. Torque Range-of-Motion (TROM) curves have been successfully applied to the improvement of therapeutic methods for the hand. The increased objectivity provided by such testing provides for accurate tracking of function and improved knowledge of mechanical function. The prototype device is used to develop the reliability and validity of TROM measurement applied to the infant normal and clubfoot during passive plantarflexion-dorsiflexion motion. It will furthermore resolve appropriate protocol for an improved design that will measure foot position in three degrees of freedom; and the torque required to position the foot throughout its passive range-of-motion. Objective mechanical properties gathered with this instrument will help design orthotic casting protocol and surgical/therapeutic procedures.