Movement degeneracy is a term derived from biology. It describes the ability to perform an action in a multitude of ways without compromising function. For example, when we walk, we can perform this movement in a number of ways given the number of degrees of freedom in our joints. Obviously most of the time we choose to walk in the most efficient manner possible. However, if we wanted to, we could walk in a number of funky ways whilst still achieving the task goal effectively (i.e., moving from A to B) . This ability to functionally move in a variety of ways is referred to as movement degeneracy.
Degeneracy is an important skill for the survival of biological systems (e.g., humans) as it allows for tasks to be completed under a variety of conditions.
With regard to skill acquisition, the presence of movement degeneracy is thought to be an indicator of an effective learning environment, as it means that the performer is learning to successfully complete tasks with multiple solutions. Indeed, if we think about our top athletes, many (if not all) exhibit the ability to perform the same task with more than one solution. For those who follow cricket, Steve Smith – the Australian captain – is the perfect example of someone who displays movement degeneracy. He will often achieve the same outcome (e.g., hitting the ball to a particular location) with a variety of methods.
See this link for an example of a study that assessed movement degeneracy in sport. See the reference below for a more detailed discussion of movement degeneracy in sport.
Seifert, L., Button, C., & Davids, K. (2013). Ky properties of expert movement systems in sport. Sports Medicine, 43(3), 167-178.