A push-pull prop comprising: - an inner tube and an outer tube which are reversibly fixed to each other, wherein the inner tube is at least partially inserted into the outer tube, - a threaded bar at least partially screwed into a threaded portion of a first end of the inner tube, said first end being opposite to a second end of the inner tube inserted into the outer tube, said inner tube, outer tube and threaded bar being arranged coaxially to one another along a common axis of the prop, - a fixing head comprising a coupling portion fixed or fixable to a first end of the outer tube, said first end being opposite to a second end of the outer tube adapted to receive the inner tube, and a locking portion rotationally connected to said coupling portion, so that said outer tube can rotate with respect to said locking portion about a rotation axis of the outer tube coinciding with the common axis of the prop in order to screw or unscrew said inner tube on or from said threaded bar, said locking portion of the prop being further configured to rotationally connect to a first connecting element of the prop at a first surface to be propped, so that the prop can rotate about a first tilting axis of the prop perpendicular to the rotation axis of the outer tube; wherein said threaded bar is configured to rotationally connect to a second connecting element of the prop at a second surface to be propped, so that the prop can rotate about a second tilting axis of the prop perpendicular to the rotation axis of the outer tube and parallel to the first tilting axis of the prop; characterized in that said fixing head comprises: - an anti-friction sliding element in the shape of a solid material ring, interposed between the coupling portion and the locking portion, and - a retaining element of the anti-friction sliding element between the coupling portion and the locking portion. - an inner tube and an outer tube which are reversibly fixed to each other, wherein the inner tube is at least partially inserted into the outer tube, - a threaded bar at least partially screwed into a threaded portion of a first end of the inner tube, said first end being opposite to a second end of the inner tube inserted into the outer tube, said inner tube, outer tube and threaded bar being arranged coaxially to one another along a common axis of the prop, - a fixing head comprising a coupling portion fixed or fixable to a first end of the outer tube, said first end being opposite to a second end of the outer tube adapted to receive the inner tube, and a locking portion rotationally connected to said coupling portion, so that said outer tube can rotate with respect to said locking portion about a rotation axis of the outer tube coinciding with the common axis of the prop in order to screw or unscrew said inner tube on or from said threaded bar, said locking portion of the prop being further configured to rotationally connect to a first connecting element of the prop at a first surface to be propped, so that the prop can rotate about a first tilting axis of the prop perpendicular to the rotation axis of the outer tube; wherein said threaded bar is configured to rotationally connect to a second connecting element of the prop at a second surface to be propped, so that the prop can rotate about a second tilting axis of the prop perpendicular to the rotation axis of the outer tube and parallel to the first tilting axis of the prop; characterized in that said fixing head comprises: - an anti-friction sliding element in the shape of a solid material ring, interposed between the coupling portion and the locking portion, and - a retaining element of the anti-friction sliding element between the coupling portion and the locking portion. said locking portion of the prop being further configured to rotationally connect to a first connecting element of the prop at a first surface to be propped, so that the prop can rotate about a first tilting axis of the prop perpendicular to the rotation axis of the outer tube; wherein said threaded bar is configured to rotationally connect to a second connecting element of the prop at a second surface to be propped, so that the prop can rotate about a second tilting axis of the prop perpendicular to the rotation axis of the outer tube and parallel to the first tilting axis of the prop; characterized in that said fixing head comprises: - an anti-friction sliding element in the shape of a solid material ring, interposed between the coupling portion and the locking portion, and - a retaining element of the anti-friction sliding element between the coupling portion and the locking portion. - an anti-friction sliding element in the shape of a solid material ring, interposed between the coupling portion and the locking portion, and - a retaining element of the anti-friction sliding element between the coupling portion and the locking portion.