Robot arm comprising: - a first parallelogram with four corner points (A, B, C, D) and four sides (AB, BC, CD, DA), wherein a first side connects a first corner point to a second corner point, a second side connects the second corner point to a third corner point, a third side connects the third corner point to a fourth corner point and a fourth side connects the fourth corner point to the first corner point, wherein the four corner points (A, B, C, D) all form hinge points; and - a second parallelogram with four corner points (E, F, G, H) and four sides (EF, FG, GH, HE), wherein a first side of the second parallelogram connects a first corner point to a second corner point of the second parallelogram, a second side of the second parallelogram connects the second corner point to a third corner point of the second parallelogram, a third side of the second parallelogram connects the third corner point to a fourth corner point of the second parallelogram and a fourth side side of the second parallelogram connects the fourth corner point to the first corner point of the second parallelogram, wherein the four corner points (E, F, G, H) of the second parallelogram all form hinge points; wherein: ∘ the first side of the first parallelogram comprises a cable-operable device; and ∘ the third side of the first parallelogram is connected to the first side of the second parallelogram; such that the parallelograms lie in the same plane and such that the fourth corner point of the first parallelogram and the first corner point of the second parallelogram coincide; wherein ∘ the third side of the second parallelogram is connected to a fixed world or reference body; wherein - a cable extending from the fixed world or reference body to the operable device is routed via pulleys rotating about the first corner point and fourth corner point of the first parallelogram and about the second corner point and third corner point of the second parallelogram; and wherein - the pulleys at the first corner point and at the fourth corner point of the first parallelogram have the same diameter; and - the pulleys at the second corner point and at the third corner point of the second parallelogram have the same diameter characterised in that the third side of the first parallelogram is connected at a fixed angle to the first side of the second parallelogram. - a first parallelogram with four corner points (A, B, C, D) and four sides (AB, BC, CD, DA), wherein a first side connects a first corner point to a second corner point, a second side connects the second corner point to a third corner point, a third side connects the third corner point to a fourth corner point and a fourth side connects the fourth corner point to the first corner point, wherein the four corner points (A, B, C, D) all form hinge points; and - a second parallelogram with four corner points (E, F, G, H) and four sides (EF, FG, GH, HE), wherein a first side of the second parallelogram connects a first corner point to a second corner point of the second parallelogram, a second side of the second parallelogram connects the second corner point to a third corner point of the second parallelogram, a third side of the second parallelogram connects the third corner point to a fourth corner point of the second parallelogram and a fourth side side of the second parallelogram connects the fourth corner point to the first corner point of the second parallelogram, wherein the four corner points (E, F, G, H) of the second parallelogram all form hinge points; wherein: ∘ the first side of the first parallelogram comprises a cable-operable device; and ∘ the third side of the first parallelogram is connected to the first side of the second parallelogram; such that the parallelograms lie in the same plane and such that the fourth corner point of the first parallelogram and the first corner point of the second parallelogram coincide; wherein ∘ the third side of the second parallelogram is connected to a fixed world or reference body; wherein ∘ the first side of the first parallelogram comprises a cable-operable device; and ∘ the third side of the first parallelogram is connected to the first side of the second parallelogram; such that the parallelograms lie in the same plane and such that the fourth corner point of the first parallelogram and the first corner point of the second parallelogram coincide; wherein ∘ the third side of the second parallelogram is connected to a fixed world or reference body; wherein - a cable extending from the fixed world or reference body to the operable device is routed via pulleys rotating about the first corner point and fourth corner point of the first parallelogram and about the second corner point and third corner point of the second parallelogram; and wherein - the pulleys at the first corner point and at the fourth corner point of the first parallelogram have the same diameter; and - the pulleys at the second corner point and at the third corner point of the second parallelogram have the same diameter characterised in that the third side of the first parallelogram is connected at a fixed angle to the first side of the second parallelogram.