An orthosis with controlled angular excursion can be positioned at the level of a joint or articulation of the human body. The orthosis includes an articulated joint with a basic structure designed to be positioned on the joint and also includes centrally, a pin with toothing located in a circular sector with predetermined width. The basic structure and the relative pin provided with toothing are equipped with a respective pair of rings, each of which has a substantially elongated shape. A hollow part, or slot, includes two straight sectors, of which at least one is provided with toothing with the same pitch as the toothing of the pin with which it engages. The pair of rings can, when in use, be simultaneously rotated around the pin, and are provided with slots which in turn include a tractor for the orthosis.