The orthosis comprises an elastic compressive distal portion extending upwards from the ankle and associated with an adjoining containment proximal portion covering a region of the calf extending between the level of the junction point between the Achilles tendon and the calf muscle and the level situated beneath the tibial tuberosity. This containment proximal portion is an essentially non-elastic deformable tubular portion made by knitting with a thermoformable yarn, and it is knitted continuously with the elastic compressive distal portion.
