A little bit of DCD

What is dyspraxia, or DCD as it is becoming more increasingly known? We hear of it frequently, it pops up on medical reports, statements and EHCPs, but what do we understand it is? A bit of clumsiness? Bad organisations skills? Bad behaviour even? Developmental Coordination Disorder, by its full title, suggests clumsiness, but how or why?

Clearly the first part, developmental, indicates that something atypical happens during a person’s early life. Given how common DCD is (and also bearing in mind that it is probably under-recognised) you would think that there is a nice battery of tests that shed light on the developmental differences that can give rise to a clear-cut diagnosis. However, no, that is not the case if you are the type of person who considers that life should be quoted in Standardised Scores (SS). To be honest, as much as SSs may be irksome, they can be a useful guide. However, tests do not diagnose, people do. The start point for diagnosis then, should surely be via SSs taken from a large population, to understand what the ‘average range’ actually is? Unless someone can correct me and point me towards some new-fangled standardised test tool, there is no ‘average’ benchmark by which to measure atypicality (if there’s such a word!).We do have standardised tests though that, when collected alongside a history and observation, can paint a sensible picture.

From infancy, we develop our motor skills. Babies kick out their arms and legs at random. They gain an idea of the muscles and thoughts used and start to create a sense of where their limbs are in space and time (proprioception). Those movements start to mature and become coordinated and a mental map emerges (motor schemas). Crawling not only needs a sense of body movements, it also requires a sense of balance (vestibular). An appropriate schema will be created. Hulme and Snowling (2009) refer to this as the ‘perceptual-motor’ skills rather than simply ‘motor-skills’, since both the vestibular and proprioceptive systems are in play. However, this is not the only ‘force’ acting on learning to crawl and walk. Humans appear hard-wired to reach certain stages of development, even without some of what we would consider the necessary stimulation. Hulme and Snowling discuss the stepping movements of an infant when held up, and the cultural practice of the Hopi people who bind infants to a cradle board for most of their first year. The bound children still learned to walk at around the same time as non-bound children. Walking therefore appears to be developmental skill that is universal.

What tends to be of the greatest difference for those with DCD is the role of visual mediation. If I see a cup on the table and wish to drink from it, my visual system works in tandem with my perceptual-motor skills to make the necessary judgements to successfully extend my arm, open my hand to the right size, apply the right pincer grip to lift the cup, then to bring it to my mouth. The schema used will be one that I have probably used thousands of times before. If the visual cue is removed, i.e. I look at the cup then close my eyes, it is highly likely that I would still successfully make all of the necessary movements to sip my drink. Even if there was a five minute delay, I will probably still enjoy a high degree of success. However, for those with DCD, there appears to be a much higher reliance on the visual system in order to make the correct motor movements.

Hulme & Snowling (2009) comment on a range of papers regarding visual mediation. One example is placing a spot on the top of a table, then reaching under the table to stick a pin in the underside where the spot is. If we have sight of the spot, we are usually pretty accurate, if we close our eyes, not so much! For those with DCD, such a task poses much greater difficulty, especially when the visual cue is removed completely. Experiments have also been done where visual cues give the brain signals that the room is rocking, when actually it is not. Those with DCD are more likely to react and sway to counter the movements than those without, to the point that they may actually fall over. ‘Clumsiness’ therefore is not really an appropriate analogy for DCD, since being clumsy would not usually result in falling over whilst standing still.

Science looks to genetics (there is a hereditary factor) and prematurity, and their effects (via the brain) on the sensorimotor map, visual-spatial perception and balance. It is suggested that those with sensorimotor map issues will have problems with fine motor skills such as writing and drawing. Gross motor skills e.g. cycling and running are linked to balance, sensorimotor map and visual-spatial skills. While, like most things, there is no agreed and definite answer, clearly not all people with DCD are going to have exactly the same problems, but all problems appear to link with vision.

It seems to me that the first port of call when considering DCD is an eye test, after all, ‘diagnosis’ is generally a process of elimination. My second port of call would be to test for visual stress. Of course, a person can have both DCD and visual stress, but a visual stress test is so quick and easy to do and can explain some of the issues also seen in DCD. Visual stress is considered visual-perceptual in nature, and although is usually related to the ‘glare’ of white paper in books, such glare may also, theoretically, link to a bright wall, whiteboard, monitor and even a pattern on a white shirt. Ruling visual stress in or out, therefore, seems rather sensible if we want students to achieve to their fullest – as well as making appropriate classroom adaptations.

DCD, like many other types of neuro-diversity appears to affect more males than females. We often hear that boys have scruffy handwriting, but could this be DCD or simply having more interesting things to do? If the handwriting is scruffy, what are their doodles like? The boy who produces perfect images of his current interest is unlikely to have DCD. He probably just finds ‘doing handwriting’ boring. If his artwork is also immature, can he tie his shoelaces? Alarm bells should start to ring, DCD or not, potentially there is a possibility of a developmental disorder. ‘Doing handwriting’ will do nothing for the boy’s self-esteem and could have a long-term knock-on effect of school disengagement. Does output suddenly increase if he word-processes? The thing with ‘developmental’ is that it is not going to just disappear. A child with DCD will grow up to be an adult with DCD, so get him on a keyboard! Come to that, build typing practice into the school week for all children.

How about P.E and sport? A child with DCD just isn’t going to return that ball in tennis unless s/he gets some practice and explicit tuition. Explicit tuition works. Brilliant! Encourage the pupil to decide which skill s/he would like to improve and set it as a target for the term – but do not expect that learning to return a tennis ball will mean that s/he will automatically transfer that skill into returning a shuttlecock. It is not the same schema. Shuttlecocks move much more slowly….. There are also a great many classroom based tasks where visual mediation may be obscured, so it is worth thinking about when presenting practical tasks.

Students with DCD are likely to have issues with fine motor skills, or both fine and gross motor skills. These problems are the result of an under-developed maturation of the sensorimotor map, visual-spatial perception and/or their balance skills. They require strong visual cues to assist in their movements, the weaker the cue, the more difficult the task becomes in relation to those who do not have DCD. I have not sought to give a detailed understanding or explanation of DCD, only raise awareness of the visual component of DCD. More food for thought than a university essay!

Reference

Hulme, C. and Snowling, M., J. (2009) ‘Developmental Coordination Disorder’ in Developmental Disorders of Language Learning and Cognition Chichester: Wiley-Blackwell

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