An end effector includes a base part and a first member. The first member includes first, second, and third serially articulated struts. The first strut articulates with the base part for relative angular displacement about a first pitch axis and about a first roll axis. The first roll axis is substantially orthogonal to the first pitch axis. The second strut articulates with the first strut for relative angular displacement about, firstly, a first yaw axis substantially orthogonal to the first pitch axis and the first roll axis, and, secondly, about a second pitch axis substantially parallel to the first pitch axis and substantially orthogonal to the first yaw axis. The third strut articulates with the second strut for relative angular displacement about a second yaw axis substantially parallel to the first yaw axis.