What kind of sensor can I use for measuring the rotational position and speed of a link in a fourbar mechanism?

Question

I work in mechanism circuit breaker design. We typically use mechanism that utilize small Θ and we therefore measure using linear travel potentiometers. On this new design, I need to measure a larger theta which will have considerable x and y motion, what kind of sensor can I use to measure the rotational position (and therefore speed, acceleration, etc.) that will not take up a lot of space? Ideally something that would mount near the origin of the output link.