A joint device for an orthoses or prostheses includes an upper part, a lower part mounted on the upper part in such a way as to turn about a pivot axis, and braking means that brakes or blocks a pivoting movement of the lower part relative to the upper part. The braking means includes a spiral spring arranged between two contact surfaces and is mounted such that it can be braced in the direction of the contact surfaces about a rotation axis parallel to the pivot axis.