Navigational abilities of typically developing individuals and individuals with Developmental Coordination Disorder (DCD)

During everyday life we walk around busy environments, negotiating stationary and moving obstacles. This is usually performed effortlessly but actually involves complex skills to visually monitor the environment and control body movements. For individuals with coordination difficulties this presents a real challenge and can have a negative impact on safe participation at school or work and in everyday life. Since little is understood about how we learn to negotiate obstacles and why some people have difficulty, this is the focus of the proposed work. We plan to investigate these skills in children and adults with and without Developmental Coordination Disorder (DCD). DCD is characterized by everyday motor problems in the absence of sensory, intellectual or neurological impairment. The condition occurs in almost 2% of children and usually continues into adulthood.

In the first phase of our work, we will describe basic patterns of gait. Research has focused on the typical development of foot placement during walking (step length and width etc) and some studies show these to be different in children with DCD, although this finding is not consistent. To our knowledge, no one has reported on acceleration or displacement of the trunk while walking in children or young adults, even though this is a common marker of loss of control in the elderly. Our research will examine both foot placement and trunk movement while walking to determine changes with age and differences between those with and without DCD.

Our research will then go on to consider locomotion while negotiating a gap/aperture between obstacles such as that created by a doorway or parked cars. Here we must first make perceptual judgements about the absolute width of the aperture and our size in relation to it. The typical developmental course of some aspects of visual perceptual abilities has been studied in detail. A range of studies also show that many children with DCD have visual perceptual difficulties. However, work in this area has involved inspection of small visual stimuli in near space, which is not relevant to locomotor behaviour (which relies on visual information from far space). The second phase of our work will therefore be the first to investigate the ability of individuals with and without DCD to make accurate visual discriminations regarding stimuli in far space.

Once a perceptual judgement regarding the size of an aperture has been made subsequent movements are adapted appropriately (e.g. turning the shoulders to pass through sideways). In our previous work we have found that in typically developing children and adults the size of these adaptations are based on the level of movement control such that the greater this control the smaller the safety margin needed between the shoulders and the sides of the aperture. In addition, the timing and magnitude of movement adaptations are tailored to aperture size, such that a reduction in approach speed is seen earlier and is greater for smaller apertures. The third phase of our research will be the first to investigate the nature of these movement adaptations in DCD.

Our research to date has focused on movement adaptations to negotiate stationary obstacles, within a predictable environment. In real life, however, we often have to navigate an unpredictable environment. This adds an additional level of complexity in terms of movement planning and often requires a mover to update or change an ongoing movement. Research on adults has found that movement adaptations to unpredictable events are left until the last few moments when approaching and obstacle. In the fourth phase of our research we plan to investigate the developmental nature of these skills and the ability of individuals with DCD to manage unpredictable environments.

The proposed research will further our understanding of the mechanisms underlying DCD and thereby assist in planning more effective interventions to support motor learning

Who will benefit from this research?
In the long term it is envisaged that both individuals with Developmental Coordination Disorder (DCD) and clinicians working with these individuals will benefit from this research through the development of intervention protocols. The UK prevalence of DCD is 2% of school-aged children; problems often persist into adulthood and continue to have a severe negative impact on everyday life. Currently, the most common intervention strategies in the treatment of DCD lack scientific rigour. There is a real need for the development of successful and cost-effective intervention programmes. The development of such programmes can only be borne out of a greater understanding of the precise nature of the movement problems in DCD. In other populations, e.g. the elderly, a better understanding of the disorder and its impact on gait has led to the development of effective intervention programmes. Movement deficits are vastly different between traumatic brain injury and DCD; however, this example illustrates how a greater understanding of a disorder can lead to effective interventions.

How will they benefit from this research?
A greater understanding of locomotor behaviour in individuals with DCD and how this sits within the typical developmental trajectory will have a positive impact in three ways. Firstly, it will be of direct benefit to researchers in the field, aiding conceptualisation and understanding of the disorder. Secondly, a comparison between TD individuals and individuals with DCD will allow observations of the similarities and differences between these groups, i.e. the aspects of movement in individuals with DCD which are not deficient. A thorough understanding of the motor difficulties and motor strengths is needed in order to plan appropriate support. It is hoped that this research will aid future work by providing an understanding of exactly where the focus of future remedial help should be. Finally, the proposed research may enable the identification and quantification of movement problems. Traditionally coarse motor assessments are used in both clinical and research settings to quantify movement ability. It has long been recognised that these measurements can only provide an overview of coordination ability. Performance on aspects of locomotor behaviour, like those described in this proposal, should give researchers a more precise quantification of movement problems and an alternative way in which the motor ability of both typical and atypical children can be described. In turn, this could also provide clinicians with a much clearer quantification of movement weaknesses that cannot be picked up through observation alone.

What will be done to ensure they benefit from this research?
A range of different communication and engagement plans are proposed which will help to meet the various positive benefits proposed above. The findings of this research project will be disseminated at several academic conferences: Developmental Section of the British Psychological Society conference, the International and National DCD conferences and the European Society of Movement Analysis in Children conference. These conferences are attended by academics and clinicians working in the arena of developmental psychology and DCD. In addition, publication of results in peer reviewed academic journals (such as Developmental Child Neurology and Gait and Posture) will target an academic audience and publication in the professional journal of the Dyspraxia Foundation will target a clinical audience. Locally, results will be disseminated to all parents of participants, the local Dyspraxia Foundation Group and Occupational Therapists known to the PI.