The rigidity of Kiwi orthotics span the entire range from very soft to hard. The stiffness of the orthotic is made to address the biomechanical needs of the patient.
One example goal of orthotic therapy is to reduce the magnitude and velocity of rearfoot and midfoot over pronation. In order to achieve this, the orthotic will be designed with an appropriate level of stiffness. Some orthotics will be more rigid than others, but none of them are truly hard and should not be uncomfortable.