iOS App goniometer for measuring ankle ankylosis. It can be considered as of paramount importance in the pathophysiology of patients with CVI since total and permanent ankle ankylosis prevents patients from being healed. In general, ankylosis is not a spontaneous complaint of patients with lower limb ulceration, even when it causes deformities and limitations. Ankle motion depends on an efficient contraction of the triceps surae muscle, which is considered a fundamental part of the calf muscle pump for the venous return from the lower limbs. Therefore, the motion of this joint is important for the efficiency of the calf muscle pump in order to prevent venous stasis and its consequences.