1. Orthosis for the treatment of injuries in knee and elbow joints, comprising at least one support structure (1) and a support pad (2) that is attached to the support structure (1); wherein said clamping structure (1) comprises an anchoring device; characterized in that: - the support structure (1) is formed by a first injected plastic material and the support pad (2) is formed by a second injected plastic material; - comprises a rigid body (3) configured by a third plastic material that is compatible with the first and second plastic materials; - the fastening structure (1) comprises a belt (1a) and a head (1b) to which the rigid body (3) and the support pad (2) are completely attached; which has been attached to said head (1b) during injections of the first and second plastic materials; where the second plastic material of the support pad (2) is more elastic and soft than the first plastic material of the support structure (1); - the rigid body (3) is embedded in the first material of the clamping structure (1) and comprises at least one annular part (3a) that surrounds the support pad (2).