Wiper arm and windscreen wiper system for a motor vehicle

A wiper arm (10), wherein the wiper arm (10) comprises a joint part (12) and a lever part (14) and a spring (13), wherein the joint and lever parts (12, 14) form a common joint (16) so that the lever part (14) has a degree of freedom (1) relative to the joint part (12), wherein the joint and lever parts (12, 14) are thereby connected to one another by the spring (13), wherein the lever part (14) is positioned along the degree of freedom (1) by the spring (13), and the spring (13) includes at least one torsion spring (13), which is disposed in a region of the joint (16), wherein the joint and lever parts (12, 14) each have a U-shaped axial cross-sectional profile, which is formed by two side elements (18) and a back element (20), wherein the side elements (18) are attached to the back element (20) and extend transversely to the back element (20), and the at least one torsion spring (13) is completely disposed between the side elements (18) of each of the joint and lever parts, wherein the side elements (18) of the lever part each have a lug (26), wherein the lugs (26) project between the side elements (18) of the lever part, and the at least one torsion spring (13) has extensions (24) for tensioning said torsion spring (13), wherein the extensions (24) bear against the lugs (26).