**2.1 Sample characteristics**

222 Learning Disabilities

The quality of motor skill performance, in this research, is analyzed in three areas of motor functioning: neuromaturation, coordination and balance. The study provides data on interaction between: (1) motor skill performance and visual or hearing impairment (between groups and single analysis). Findings are compared with the aim of establishing if there is strong evidence for or against the effect of visual or hearing impairment on motor skill performance; (2) motor skill performance of children with visual impairment, as much as motor skill performance of children with hearing impairment, with the aim of establishing if there is a similarity or some kind of pathway which can help professionals in creating rehabilitation programmes, as much as programmes for adaptive physical education; (3) motor skill performance and common child variables, such are gender and age. Gender differences in motor skill performance for children and adolescents in general may exist because of differences in body composition during growth and maturation, and social influences regarding physical activity. Generally, the magnitude of differences in motor performance between boys and girls is low to moderate during childhood, and girls are low to moderate during childhood, but this changes quite markedly after puberty when boys tend to outperform girls (Thomas & French, 1985, as cited in Houwen et al., 2009b); (4) the previous findings of the authors Nikolić, Ilić-Stošović (2009) that are related to motor skill performance of children with typical development are examined in all three groups with the aim of establishing differences or a similarity in prevalence and structure of motor skill

Why did we decide to do such a study? Sensor integration is essential for obtaining a complete experience of phenomena and activities that surround us. It is basic for mostly learning situations. Sensor integration, thus integration of auditive and visual information, is basic for creating, defining and interpretation of terms. Disabilities in this area may influence development of all academic skills, and also other skills, especially motor skill. From the other side, integration of perception and motor activities primarily is related to visual-motor coordination and audio-motor integration. Visual-motor integration implies ability of visual and motor coordination. Difficulties in this area, potentially, can disturb all areas of a child's life: social, academic, sports and practical. The child, because of lack of visual control of motor activity, organises its movement in space and time inadequately. Audio-motor integration includes compliance of motor activities with verbal and non-verbal stimulus, such as melody, rhythm etc.. Spurious capacitance response in this area can be directly reflected in the development of academic skills (Gligorović et al., 2010). The situation becomes more complicated if a child is born with sensor impairment, or during early development copes with sensor impairment. What than happens with motor skill development and performance? Is it possible, although both with sensor, but one group with visual and the other with hearing impairment, that there are some similarities? This

The truth is that there are a lot of studies that are related to motor skill performance of children with visual impairment and a lot of articles with the studies that are related to balance disorders and motor outcomes of children with hearing impairment. Also, many of those studies compared the motor skill performance of children with visual or hearing impairment and children with typical development. But there are only a small number of studies that examined motor skill performances (not only balance) in children with hearing impairment, in spite of some evidences (see in Vujasinović, 1997; Narančić, 1997; Butterfield, 1986; Rine et al., 2000; Kohen-Raz & Masalha, 1988; Hartman et al., 2011) that children with

was a question that we tried to answer through our research.

performance.

The 73 pupils were children with different degrees of hearing impairment (HI) and 83 were children with different degrees of visual impairment (VI). The group of children with visual impairments consisted of two subgroups: children with blindness whose range of vision ranges from 0.02 to a complete absence of quantitative and qualitative vision, and children with low vision, whose range of vision ranges from 0.3 to 0.05. The sample is a balanced representation of the children with blindness (41.94%) and low vision (48.38%). The group of children with hearing impairments consisted of children whose level of hearing loss ranged from 45-59dB (ASA) or 56-70 dB (ISO) of them 17.73%, then 25.32% of children with hearing impairments whose level of hearing loss ranged from 60-70 dB (ASA) or 71-90 dB (ISO) and 56.95% of children with very hard hearing impairments (80 dB and more (ASA) ili 91 dB and more (ISO))2.

According to psychological documentation, all children were of average intelligence. All children were between 7 and 14 years of age. The distribution of the total sample according to gender is equal (boys 53.2% and girls 46.8%) and does not show a statistically significant difference (Pearson's R: Value ,022; Approx. T (b), 268; Approx. Sig. ,789(c)).

All children attended schools for education children with visual/or hearing impairment (special schools) in Belgrade, Republic of Serbia.

#### **2.2 Material**

The main criterion for the selection of test materials was that the methods used had to be appropriate for testing children of middle childhood age (psychological/pedagogical periodization of children's development) and to evaluate the most important functions for this period of life: neuromaturational maturity (a symptom of synkinesia, diadochokinesia

<sup>2</sup> This paper shows an empiric segment of the macro-project "Phenomenology of Developmental Disturbances and Disorders", which was realized at the Faculty for Special Education and Rehabilitation, University of Belgrade, and approved by the Ministry of Science and Technology of Republic of Serbia (number of license: MNTR 1611).

Motor Skill Performance of Children with Sensor Impairments 225

a different hand.. In assessing diadochokinesis, the child is given an order to relax one arm next to the body and the other bent at the elbow near the body, and then to perform rapid, alternating movements of supination and pronation.. This assessed the presence of second

Motor impersistence is examined by requesting for the child to stand upright, arms outstretched in front of him, fingers outstretched, mouth open, eyes closed for 30 seconds. Assessments are based on the possibility of maintaining a given position, without vocalization, moving the fingers, tongue and other body parts. Inhibitory control mechanisms are used to control interference, modulation or interruption of ongoing activities, which are basically a series of other cognitive functions and abilities such as attention, working memory, understanding, planning, regulation of motivation and emotion (Brocki, Bohlin, 2004; Eisenberg, Smith, Sadovsky, Spinrad, 2004), theory of mind and social competence (Carlson, Moses, 2001). Inhibition of motor activity usually matures about 6-7 years, unlike the inhibition of linguistic, conceptual and mnestic stimuli showing a longer development trend (Welsh, 2002). Inhibitory control deficit, which is one of the basic mechanisms of executive functions, is a very important factor in the weak achievement in all tested parameters of sensomotor skills and abilities that are prerequisite for the

These indicators of possible delay in the development of the central nervous system are normally present in children before they start to attend school. Related to our sample, there are 26.9% of the children with symptoms of synkinesis, 26.3% with symptoms of

Comparing children with hearing impairment and children with visual impairment, we can see that symptoms of synkinesis were noticed in 31.5% of children with HI and in 22.9% of children with VI. Symptoms of diadochokinesia were noticed in 13.7% children with HI and in 37.3% children with VI. Symptoms of motoric impersistence were noticed in 26% of children with HI and in 20.5% children with VI. (Figure 1). In relation to the type of sensory impairment, the results indicate an equal distribution of the symptom of synkinesia (Pearson's R: Value -,097; Approx. T (b) -1,208; Approx. Sig. , 229(c)), and of motoric impersistence (Pearson's R: Value -, 066; Approx. T (b) -, 817; Approx. Sig. , 415(c)), but the prevalence of diadochokinesia is statistically significantly and increased in the children with visual impairment (Pearson's R: Value, 268; Approx. T (b) 3,454; Approx. Sig., 001(c)). The reason for such increasing of symptoms of diadochokinesis in children with visual impairment can be found in the lack of opportunities for movement experience, lack of effects of graphomotor experience (writing), which has important influence on neurological development of muscles that control fine motor movements. It is believed that children with visual impairment often have fewer opportunities to interact with the environment, which may lead to limited movement experience. Furthermore, it is generally assumed that those with a greater amount of task-specific experience perform

Additional research is needed in this area. Issues that need to be addressed include association of level of hearing/visual impairment with delaying in neuromaturnational development. Also, it is important to research how school programmes, environment and special or mainstream education influence development of this motor skill performance.

diadochokinesia in 23.1% of the children with signs of motoric impersistence.

hand synkinesis and separation of the shoulder and elbow forces on active hands.

development of academic skills.

better (Houwen et al., 2009)

and motor impersistence, as much as symptom of dyslateralisation); balance; and coordination (general motor skills and visuomotor coordination). Levin M.D. (1980) tests were used for evaluation of neuromaturation and Bruininks-Oseretsky Test of Motor Proficiency (Bruininks 1978) and the ACADIA test (Atkinson, Johnston, Lindsay, 1972) were used to evaluate coordination and balance. The tasks were selected on the basis of chronological age of the children, because they have been widely used in similar research and because they have standardized methods for interpreting the results. The outcome of Dügers et al.'s (1999) study, with the primary objective to research the relationship between motor abilities and demographic characteristics, such as age and sex, in healthy children aged 4-11 years, revealed that the Bruininks-Oseretsky test can be useful to investigate unexplored aspects of motor development. This was one more reason to choose this test for our research.

Every child was tested individually in separate rooms, without other children present, but with presence of two researchers and a class teacher. The testing did not start until the child was relaxed and ready to cooperate. Tasks were explained verbally to the child. In the situation where the child couldn't understand verbal directions, the researchers demonstrated the desired response. We took into account that, regarding the children with hearing impairment, we had to say the tasks clearly, simply, in short sentences, and for the pupils of higher classes we had prepared the tasks written in big Cyrillic letters. In some cases, if a task was not clear, we used demonstration as well. Children with visual impairment perceive verbal demands well, and constructing the protocol we took into account its adaptability for this category (the imitation tasks were omitted, as well as those which first require the reception of visual information and then motoric performance). Small help of the researchers was given, mainly for balance and coordination tasks.
