A medical positioning apparatus for positioning and holding an object, including: a telescopic member; a support member for receiving the object; a base member securable to a base; a first and a second joint mechanism movably securing the telescopic member to the support member and the base member and each having at least two rotational degrees of freedom; a locking device operatively connected to the joint mechanisms and the telescopic member, the locking device operable between a locked position in which the configuration of the positioning apparatus is fixed, and a released position in which the configuration of the positioning apparatus may be changed, the locking device being passively biased in the locked position; and a lock activation device to unlock the locking device in order to change the configuration of the positioning apparatus.