Moving our bodies through space and interacting with objects is remarkably complex and subtle (see Motor coordination.) We do these things so effortlessly and unconsciously that we are unaware of how much is going on behind the scenes. One way to see this is when something goes wrong, as in Apraxia. In some forms of Blindsight, people who have no conscious vision are still able to do tasks such as putting a letter into a mail slot or walking through a maze. These actions are done equally unconsciously in normal people, but the very independence and cleverness of the unconscious motion planning becomes clear in blindsight victims because they can still perform these complex actions even though brain damage prevents any conscious visual perception. See Phantoms in the Brain for more neurological evidence.
The complexity of algorithms that attempt to duplicate human action is also evidence of the hidden complexity. See Motion planning and Planning Alogrithms (online book). The simple feat of moving in a controlled way is a considerable challenge, especially when we consider highly dynamic actions such as running or jumping. Though recent walking robots are impressive (and creepy), earlier robots shuffled like invalids; it took 40 years of work, and substantial complexity.
While we emphasize the innate talent for motion and action that we take for granted, consider also the unconscious nature of skilled performance such as dance, athletics or playing a musical instrument. Considerable practice is required to reach high levels of performance, but even ordinary amateur competence requires sufficient practice that the appropriate motion can be made unconsciously (see Muscle memory.)
From an evolutionary perspective, we can see that it is unremarkable that action is an Unconscious process. Not only is consciousness poorly suited to this sort of fast-fuzzy-subtle undertaking, there was also no need for consciousness to become involved because action and motion at this level was already well developed in ancestors that lacked conscious thought. See Representational Opacity.