We've probably all been clumsy from time to time -- knocking over the teacup on the desk when reaching for a pencil, dropping a jar when moving from the kitchen to the table, tripping on an uneven bit of sidewalk when walking the dog. We sometimes refer to this kind of behavioral mistake as "maladroit".
Can we give an explanation of clumsy behavior?
Here as elsewhere, a little conceptual work is helpful. We might characterize a clumsy event as "an inadvertent negative result of a series of bodily movements intended to accomplish something else altogether." And, it would seem, we need to add a characteristic of causation into the definition: the negative result came about as a consequence of the agent's series of actions and movements -- not simply an unfortunate coincidence. The actor bears responsibility for the negative result in some way. (We wouldn't call it "clumsy" if I knock over the glass of wine because the waiter has just placed it at my elbow and out of my visual range; rather, this is simply an accident.)
It is also useful to consider the contrast that is intended by the use of the concept. The contraries of "clumsy" seem to include adjectives such as skillful, adroit, agile, graceful, or deft. (And consider whether there are nuances of differences among even these positive valence adjectives.) The idea of the degree of bodily control exercised by the actor comes into all of these concepts, both negative and positive. The agile and graceful person -- an athlete or a dancer -- is praised for his/her ability to place the body in exactly the way she wishes to. The clumsy person trips, drops, smashes, and spills -- that is, he/she lacks the ability to control the results of bodily movements.
So "clumsy" is a feature of bodily performance, in which the intended course of affairs has gone wrong. It is a defect of performance and, derivatively, a defect of competence. A clumsy person is one who is prone to committing more than his/her share of clumsy actions. To refer to a movement or a person as clumsy is to find fault (though perhaps without blame); it is to highlight a deviation between what we expect of normal behavior and the observed behavior.
So what is the standard of competence and performance that we implicitly have in mind when we deploy the standards of "adroit" and "clumsy" when it comes to physical performances? It's something like this. We recognize, first, that every physical action is actually a complex and orchestrated series of component movements. To catch a high fly ball requires the outfielder to predict the destination of the ball; to organize his leg and body movements in order to run to the destination; to prepare for the leap into the air; to extend the glove arm and snag the ball. But more prosaically, to pour a glass of water has a lot of the same complexity of orchestrated movements and calculations. Both activities require "body intelligence" -- an active (unconscious) process of orchestration of sub-movements into larger perfomances.
Second, there is a substantial amount of knowledge gathering, calculation, and projection that is required in order for the actor to form a cognitive map of the arena of action: where the target will be at a particular point in time, what obstacles exist in the environment, and how the bodily movements need to be orchestrated on such a way as to avoid the obstacles and achieve the desired outcome. The waiter approaching the table to refill the water glasses is illustrative: he/she needs to observe and record the placement of the guests, their glasses, the floral arrangements, and the random items on the table; he needs to approach in such a way as to avoid contacting the guest or spilling the water on the guest; he needs to navigate the pitcher past the guest and between the flower arrangements; bring the pitcher adjacent to the water glass; and pour just enough water into the glass to fill it. Mission accomplished, he needs to withdraw the pitcher without knocking over the flowers or spilling on the guest. And, since the guests are in motion, be needs to regularly update the representation of the field of play and be alert to the possibility of sudden movements by the guest.
In other words, we expect quite a lot from the "adroit" waiter from the point of view of active knowledge gathering and skillful orchestration of movements based on the current cognitive map -- representation of the world and management of the body. The adroit person is one who has a reasonably good representation of the physical spaces around himself/herself; has a reasonably good ability to project the future configuration of the space; and has a reasonably high ability to orchestrate the series of movements needed to accomplish a task and a high ability to bring the body to implement the resulting series of steps.
So where does "clumsy" come into this story? Evidently, clumsy mistakes can derive from any of these three sources. The cognitive representation of the field may be incorrect or glaringly incomplete (the waiter may have failed to note that the guest is particularly tall and consequently bumped his head in his forward motion) (faulty representation). Second, the waiter may miscalculate times and distances -- he may think he can just clear the guest's arm gestures as he passes with the water pitcher (faulty calculation). Or he may have a faulty ability to orchestrate his own physical movements. He intends to touch the pitcher to the lip of the water glass, but he over-shoots and breaks the glass (faulty orchestration and/or faulty implementation).
So now we might speculate a bit: a clumsy person may be clumsy in virtue of deficiencies in any of the three areas -- representation, calculation, and orchestration -- and the nature of the clumsy performance is different for each of the three forms of deficiency. The first person may be clumsy because he/she doesn't pay a lot of attention to the field of play; builds up an incomplete representation of the placement of the furniture; and, as a result, bumbles into the footstool or the coffee table. Or there may be another sort of cognitive defect -- for example, a limited ability to remember the features of the cognitive map that has been developed -- he keeps forgetting the footstool. The second person may have a deficient ability to project future states of the field of play based on its current state. He sees the revolving door in front of him, but mis-estimates how quickly it is moving and collides with it. The third person may have a full and sufficient cognitive representation of the field of play; may be fully able to run the dynamics forward in time through mental calculation; but may have difficulty in arranging the movements of the body accordingly. And this deficiency in turn may derive from various causes -- a defective implementation of the routines of motion, an awkward geometry of the body so there is systematic misplacement of the feed, a slow neurological process leading to body movements that aren't quite in synch, ...
And here is one final thing we might observe, based on this treatment. A single clumsy act can be explained as the result of a single moment of bad performance -- lapsing of attention to the environment, failing to calculate carefully the relevant future states, stumbling. An enduring characteristic of clumsiness, on the other hand, invites an explanation based on a feature of deficient competence in one of the areas mentioned above -- a chronic problem in the actor's cognition of the environment, or the actor's ability to project future states, or the actor's ability to orchestrate and control the movements of the body. And, if we were in the "clumsy-therapy" business, we might try to identify where the deficiency lies and then try to find ways of improving the actor's competence in this area.
What kind of analysis is this? Partially it is an ordinary language analysis, along the lines of J. L. Austin. It involves diving into the nuances of meaning that we have in mind when we describe certain actions as "clumsy." But partly it is a phenomenological inquiry: what is the state of mind and body that is associated with committing "clumsy" mistakes? What is the "life world" of imperfect performance? (Hubert Dreyfus (A Phenomenology of Skill Acquisition), Samuel Todes (Body and World), and Richard Sennett (The Craftsman) capture different parts of this perspective.) And, finally, it is a bit of speculative cognitive psychology; it is an attempt to work out the structure of the cognitive and motor activities that need to occur in the normal performance of activities like catching a fly ball or pouring a glass of water. And, based on this schematic analysis, it is an effort to see how the mistake of "clumsiness" can emerge from normal skilled performance. This is analogous to Noam Chomsky's inventive use of grammatical "mistakes" as a clue to the underlying grammatical competence possessed by normal language users.