Motorized positioning arm

A motorized positioning arm for at least one of positioning instruments and, medical instruments, the motorized positioning arm comprising:

• at least two arm elements connected to one another so as to be pivotable about a pivot axis by a central joint, wherein at least one of the at least two arm elements comprises a further joint at an end opposite to the central joint,
• wherein the motorized positioning arm further comprises a blocking mechanism configured to block and release the central joint and the at least one further joint,
• wherein the blocking mechanism further comprises a central shaft arranged coaxially with the pivot axis, and at least one transmission device from the central shaft to the at least one further joint,
• wherein the blocking mechanism further comprises an electrical blocking device in engagement with the central shaft so as to enable blocking and unblocking of the joints, and
• wherein the electrical blocking device is configured and arranged to move relative to and along the central shaft, thereby blocking or unblocking the joints.