An apparatus for measuring athletic performance includes a swivel joint that includes a housing, a coupling member and a sensing device. The housing includes first and second arms, each arm defining an aperture therethrough, the arms defining a gap and being oriented with the respective apertures aligned across the gap from one another. The coupling member includes an axle that passes through the apertures, is rotatable with respect to the housing, forms first and second attachment points, and forms a protrusion that extends outward from the axle. The coupling member further includes a bar that couples with the attachment points, and curves sufficiently to clear ends of the arms as the axle rotates within the apertures. The sensing device is responsive to produce an electrical signal representative of athletic performance when rotation of the coupling member moves the protrusion through a predefined rotational position within the gap.