The effects of a manipulative skills intervention programme on the motor proficiency of adolescents with intellectual disabilities

With this study we aimed to investigate the impact of a 12-week manipulative skills exercise programme on the motor proficiency of young individuals with intellectual disabilities. A total of 32 learners diagnosed with mild intellectual disabilities, with an average age of 17.81 ± 1.44 years, were divided into 2 equal-sized groups: a control group and an experimental group engaged in a manipulative skills intervention programme. Motor proficiency was assessed using the short form of the Bruininks-Oseretsky Test of Motor Proficiency Second Edition (BOT™-2), while the participants’ coordination level was evaluated using the Body Coordination composite of the BOT™-2. Results show that the manipulative skills intervention programme led to significant improvements in the experimental group’s total motor proficiency score on the short form BOT™-2 (45.31 ± 12.01 vs. 37.12 ± 7.00, ANCOVA: F = 48.65, p = 0.00) as well as the Body Coordination composite (42.69 ± 11.31 vs. 39.84 ± 11.75, ANCOVA: F = 44.35, p = 0.00). These findings suggest that the experimental exercise programme had a positive effect on enhancing the motor proficiency of young individuals with mild intellectual disabilities.


Introduction
Young individuals with intellectual impairments (ID) commonly experience notable restrictions in their intellectual functioning and adaptive behaviour (Maïano, Hue & April, 2019).Intellectual functioning pertains to cognitive capabilities such as reasoning, problem-solving, and learning, which typically fall below average compared to their peers.On the other hand, adaptive behavior encompasses the practical skills required for everyday living and social interaction (Top, 2015).Motor problems are a common issue in people with intellectual disabilities because intellectual disabilities have been known as one of the frequent causes of cognitive and motor function impairment (Cleaver, Hunter & Ouellette-Kuntz, 2009;Hartman, Houwen, Scherder & Visscher, 2010).In addition to these deficiencies, individuals with intellectual disabilities are known to exhibit reduced motor skill proficiency across all ages, due to a sedentary lifestyle, fewer opportunities for physical exercise and the nature of the disability itself (Lotan, Isakov, Kessel & Merrick, 2004;Stanish, Temple & Frey, 2006).
The significance of enhancing motor skill performance in children with borderline and mild intellectual disabilities (ID) is underscored in a study conducted by Vuijk, Hartman, Scherder and Visscher (2010).There was a correlation between the degree of ID and the performance of manual dexterity, ball skills, and balancing skills in children with ID and a substantial increase in borderline and definite motor impairments compared to the normative sample (Vuijk et al., 2010).The findings of this study provide evidence supporting the idea that there is a connection between the level of motor and cognitive functioning in children with ID.This is because having sufficient motor skills can contribute to long-term engagement in physical activities, participation in sports, and the adoption of healthy lifestyles, ensuring a lifelong enjoyment of such pursuits (Vuijk et al., 2010).

Literature Review
The vast majority of earlier motor studies focused on how children's motor systems functioned (Hartman et al., 2010;Jenni, Fintelmann, Caflisch, Latal, Rousson & Chaouch, 2015;Vuijk et al., 2010;Wuang, Wang, Huang & Su, 2008), whereas only a small number of studies have had adolescents as their main respondents (Ninot, Bilard & Delignières, 2005;Ninot, Bilard, Delignières & Sokolowski, 2000;Top, 2015).Maïano et al. (2019) conducted a systematic review where they examined the results of 14 studies in which the impact of motor skill interventions on fundamental movement skills (FMS) in children and adolescents with intellectual disabilities (ID) were investigated.The review found that most of the studies focused on children with ID and their balance skills.The findings from these studies strongly indicate that motor skill interventions are highly effective in improving balance skills in children with ID (Maïano et al., 2019).In other words, the results suggest that children with ID showed a significant improvement in their balance skills when participating in motor skill interventions.
According to Han, Fu, Cobley and Sanders (2018), the most beneficial duration and training load (session duration and frequency), as well as the exact measure of long-term sustainability of motor skill interventions, remain unknown.The authors of the study (Han et al., 2018) recommend that future research should focus on examining these matters in more detail, with a particular emphasis on enhancing the methodology of motor skill interventions for younger individuals with intellectual disabilities.

Theoretical/Conceptual Framework
At this point, according to Maïano et al. (2019), insufficient evidence was available to clearly indicate whether motor skill interventions were in fact effective with regard to the improvement of locomotor and object control skills in children and adolescents with intellectual disabilities.The effects of motor skill interventions on the fundamental motor skills of children and adolescents with intellectual disabilities should be more systematically investigated in subsequent studies (Han et al., 2018).Işık and Zorba (2020) have conducted a research study reporting that the balance and coordination capacities of individuals with intellectual disabilities can be improved by implementing basic training programmes.These training programmes, however, must take into account an adequate level of exercise and the degree of the disability.In this respect, Işık and Zorba (2020) clearly demonstrate the effectiveness of the basic training programme of hemsball as a sport, especially in the case of those individuals diagnosed with moderate intellectual disabilities.According to the international education system, as advocated by Hall and Theron (2016), the most equitable approach to supporting individuals with intellectual disabilities (ID) is by integrating them into regular mainstream education.
Inclusion pertains to the practice of educating learners with disabilities, including intellectual disabilities (ID), in regular classrooms alongside their typically developing peers providing them with the necessary support and accommodations to address their individual needs (Hall & Theron, 2016).
As practice has shown, modern medicine cannot guarantee the treatment of intellectual disability (Jankowicz-Szymanska, Mikolajczyk & Wojtanowski, 2012).However, additional opportunities are available to significantly improve the quality of life of people with intellectual disabilities.These opportunities include engaging in physical exercise to improve coordination, posture, and overall daily functioning, as highlighted by Bertelli and Brown (2006).Different models of physical exercise have thus shown to have a notable impact on the overall improvement of motor skills (Bertelli & Brown, 2006).Further research on the effects of various exercise programmes can help identify those that are particularly effective for this population.However, none of the motor skills interventions reviewed in earlier studies have focused on the locomotor and object control skills of adolescents with ID.The aim with our study was, therefore, to determine the effects of a 12-week manipulative skills exercise programme on the motor efficiency and body coordination in adolescents diagnosed with mild intellectual disabilities.

Method Participants
The participants in the study included 32 learners from the special school "14 October" in Nis, Serbia, who were diagnosed with mild intellectual disabilities.The sample consisted of 22 male and 10 female participants, with an average age of 17.81 ± 1.44 years at the beginning of the study, or 18.06 ± 1.33 years at the final measurement.The average body mass was 70.40 ± 17.53 kg, the average height was 170.89 ± 11.52 cm and the average Body Mass Index (BMI) was = 24.19 ± 6.20 kg / m 2 .The sample was randomly divided into two smaller subsamples.An impartial researcher was assigned the task of generating random numbers (using a computergenerated randomisation method) in order to allocate participants into groups.The researcher conducting this task was unaware of the group assignments, maintaining blinding throughout the process.The experimental group consisted of 16 learners (11 male and five female participants) aged 17.70 ± 1.33 at the initial measurement (i.e., 17.95 ± 1.53 years at the final measurement).The weight and height of the individuals were assessed using a calibrated electronic scale.The measurements were taken while the participants were wearing lightweight sports clothing and without shoes.The average body mass in this group was 69.64 ± 18.87 kg, body height 186.34 ± 13.30 cm and BMI 24.86 ± 7.46 kg/m 2 .The members of the experimental group took part in an experimental exercise programme during the physical education classes.The exercise sessions occurred twice a week for a duration of 12 weeks, with each session lasting 45 minutes.It is worth mentioning that, given the sensitivity of the population involved, the attendance rate in the experimental exercise programme was notably high.On average, the attendance rate was 77.46% (specifically, 79.63% for girls and 76.39% for boys).At the beginning of the research, the inclusion criteria for attendance were established at 75%.
A total of 16 learners comprised the control group, 11 of whom were male and five female.At the initial measurement, their average age was 17.87 ± 1.56 years (or 18.12 ± 0.90 years at the final measurement).The members of the control group had an average body mass of 69.91 ± 17.42 kg, body height of 173.28 ± 9.15 cm, and BMI of 23.14 ± 5.05 kg/m².These individuals participated in general physical education sessions, attending twice a week for a duration of 12 weeks, with each session lasting 45 minutes.
The participant selection was authorised through a decision by the Ethics Board at the Faculty of Sport and Physical Education, University of Nis.After obtaining the required approval, the learners' guardians provided informed consent forms, which included medical reports confirming their suitability for participation in the programme.Following this, a meeting was conducted with the parents of the 32 learners with intellectual disabilities to provide them with detailed information about the study.

Testing Procedures
The measurement tools used to evaluate motor skills consisted of the short form of the Bruininks-Oseretsky Test of Motor Proficiency, Second Edition (BOT™-2) (Bruininks & Bruininks, 2010), along with two specific subtests from the BOT™-2: the bilateral coordination and balance test battery.These assessments were employed to gauge the participants' development in terms of body coordination.The BOT™-2 test was specifically designed to detect minor to moderate motor coordination impairments in individuals aged 4 to 21.All the subtests within the bilateral coordination and balance section were collectively referred to as "33 total motor composites of body coordination."Qualified professionals who were experienced in working with adolescents with mild intellectual disabilities administered both the pre-and post-tests and the intervention programme.To ensure consistency, all participants were required to visit the gym and undergo the testing procedures at the same time of day.The gym was appropriately illuminated and air temperature of 22 °C was maintained.

The Manipulative Skills Intervention Programme
The exercise programme used in the experimental group encompassed not only exercises targeting the enhancement of manipulation skills but also exercises aimed at improving various motor abilities, such as strength, speed, bilateral coordination, upper body coordination, balance, manual dexterity, running speed, and agility.
The exercise programme included polygons with balls from a variety of sports such as basketball, volleyball, handball and tennis.The experimental exercise programme lasted for 3 months (12 weeks), with 2 additional weeks that served to facilitate the initial and the final measurement of the participants' overall motor proficiency.The experimental exercise programme was integrated into the regular physical education classes and held twice a week for 45 minutes.Prior to the start of the programme, an initial measurement was conducted.The participants in the experimental group followed a specifically designed exercise programme outlined in Table 1.On the other hand, the control group participants engaged in the standard activities programme, which was a part of the regular physical education classes offered in secondary schools as recommended by the Ministry of Education of the Republic of Serbia.The final measurement was carried out upon the conclusion of the experiment.The members of the control group attended regular physical education classes at school, twice a week for 45 minutes.Throughout the experimental period, the control group participants did not engage in any additional exercise programme apart from the one prescribed by their regular physical education classes.

Statistical Analysis
The collected data from the study were analysed using Statistical Package for the Social Sciences (SPSS) 20.0 for Windows.The results of the Kolmogorov-Smirnov test indicate that the data followed a normal distribution (p > .005).To assess the differences between the two groups, analysis of variance (ANOVA) and analysis of covariance (ANCOVA) were employed.Statistical significance was considered at a threshold of p ≤ 0.05.

Results
Table 2 presents the descriptive statistics for both groups of participants and the results of the ANOVA analysis.The absence of statistically significant differences in age and BMI indicates the overall similarity between the two groups being examined.
In addition, Table 2 also displays the mean, standard deviations, and between-group differences for the pre-training and post-training measurements.No statistically significant differences were observed between the two groups during the initial measurement.However, the final measurements showed a significant difference in the total score of the BOT™-2 short form (F = 5.54, p = 0.025), as well as in the balance, bilateral coordination, and coordination composite score.

Discussion
A fairly limited number of studies exist in which changes in motor abilities of children and adolescents with mild intellectual disabilities, especially after the implementation of an experimental exercise programme were examined.Referring to children or adolescents with intellectual disabilities, the most frequent approach is the screening of either specific motor abilities or overall motor skill proficiency (Jeoung, 2018).The lack of consistency in the use of certain test batteries, aimed at evaluating motor abilities of children and younger people with mild to moderate intellectual disabilities, makes it difficult to monitor and compare the results obtained by different studies (Frey, Stanish & Temple, 2008).The short form of the BOT™-2 test battery allows researchers to analyse the overall results using standardised values.Our study expands on the standardised data and also considers the ages of the participants.While only one variable (the BOT™-2 short form total motor proficiency score) showed statistically significant differences between groups in the initial analysis, the ANCOVA analysis revealed differences in all the variables examined.
The experimental exercise programme consisted of numerous tasks involving tennis balls (throwing, catching, rebounding, target-based shooting, etc.), contributing to a significant improvement in the individuals' manual abilities.Thus, the obtained results are in line with the results of the research conducted by Top (2015) and Wuang et al. (2008).In the latter two research studies the authors also found a statistically significant change in the composites of the Manual Coordination and Fine Manual Control (Wuang et al., 2008).This was also the case in the two additional subtests, i.e. the Fine Motor Precision and Fine Motor Integration (Top, 2015), respectively.Wuang, Ho and Su (2013) examined the impact of a 20-week long individual home therapy on the motor abilities of children with mild intellectual disabilities aged 6 to 12 years.The exercise programme was conducted individually at home, with each participant dedicating 15 minutes to daily sessions.The results showed that after 10 weeks, there was no significant difference in motor abilities between the experimental and control groups.However, after 20 weeks, statistically significant differences were found in specific areas.The composites of fine manual control and manual coordination showed a significant difference (p = 0.02).However, no significant differences were observed in the other composites, namely body coordination (p = 0.42) and strength and agility (p = 0.30).
Similar to our study, Top (2015) examined changes in the motor skills of a population of young people with mild intellectual disabilities (aged 17.43 ± 1.55) after a 10-week swimming programme implemented three times a week, for 60 minutes.
The programme itself was prescribed by the Special Olympics movement.The obtained data were interpreted using subtests rather than composites.Nevertheless, similar results to those of our study were obtained.A statistically significant difference was observed between the experimental and the control group in the final subtest testing, i.e., in the fine motor precision (p = 0.035), and fine motor integration (p = 0.036).However, in contrast to the results of our study, no statistically significant difference was found with reference to the total motor proficiency score (p = 0.799).
Furthermore, it should be noted that all members of the experimental group, irrespective of gender, actively took part in the exercise programme, attending approximately 77.46% of all the classes.Among the boys, the attendance rate was 76.39% of classes, while girls had a slightly higher attendance rate of 79.76% of classes.This represents a noteworthy precedent, considering the fact that girls tend to avoid physical education classes once they enter puberty (Duncan, 2007).Owing to such heightened motivation, learners in our study seemed to have performed more complex tasks without major difficulties.As a result, this may have played a role in the positive outcomes observed in the intervention exercise programme.
Although a large number of balance and polygon exercises, aimed at improving body coordination, were included in the experimental exercise programme, no statistically significant changes were observed in this particular motor ability.Similar results were obtained by Top (2015) and Wuang et al. (2013) in their research studies.Nevertheless, the studies conducted by Giagazoglou, Arabatzi, Dipla, Liga and Kellis (2012) and Giagazoglou, Kokaridas, Sidiropoulou, Patsiaouras, Karra and Neofotistou (2013) demonstrate that adequate exercise programmes have the potential to enhance balance abilities.Giagazoglou et al. (2012) examined the impact of a 12-week trampoline exercise programme on the motor abilities of children with moderate intellectual disability with a mean age of 10.3 ± 1.6.In terms of frequency, the exercise programme was carried out on a daily basis, for 20 minutes and it was customised to meet the needs of individual participants.In an additional study, Giagazoglou et al. (2013) examined the effect of a 10-week riding therapy programme in a sample of children with a mean age of 15.3 ± 2.1, who were diagnosed with intellectual disabilities.Both studies employed an electronic platform to test balance and in both cases there were statistically significant changes in the balance variables: standing on one leg with open eyes, and standing on one leg with closed eyes.As the findings of the last-mentioned two studies suggest, it is possible for an experimental exercise programme to influence balance.This, however, was not the case in our study.One of the interfering factors in the ability monitoring domain in our study may have been the choice of the balance tests for the short form of BOT™-2 (provided by Bruininks & Bruininks, 2010).The previous body of research (Dehghani & Gunay, 2015;Kachouri, Borji, Baccouch, Laatar, Rebai & Sahli, 2016;Mehralitabar, Mirjalali, Minoei & Fadaee, 2015) shows a significant improvement in the intervention group, and Gupta, Rao and Kumaran (2011) and Işık and Zorba (2020) report a significantly higher posttest balance skills value, or pre-test to post-test change value in balance skills in the intervention groups compared to the control groups.Finally, a significant pre-test to post-test improvement in the balance skills was reported in the intervention group that was a part of the study by Işık and Zorba (2020).
Based on an analysis of the implemented exercise programme, the resulting outcomes, and a comparison with previous relevant research studies, it can be concluded that the programme used in our study demonstrated effectiveness in enhancing overall motor skills and body coordination.In addition, no health and psychological deterioration was observed in the group with mild intellectual disabilities.All the exercise programmes analysed above in the available, as well as in our research, were implemented in three different ways alone: within regular physical education classes, post regular classes, or individually at home on a daily basis.These three settings should be taken as guidelines for further research.
Increased body awareness resulting from the overall enhancement of motor skills facilitates greater engagement in physical activities, whether it be during physical education classes, sports, or recreational pursuits (Best, 2010).This applies regardless of whether individuals participate alongside peers with impairments or younger individuals without impairments.The practical significance of our research study is that it provides practical guidelines on how certain aspects or the entire experimental exercise programme can be readily implemented within physical education classes in inclusive high schools.In addition, learners in our study seemed to readily accept this exercise programme, which, as this study shows, contributes to the overall increase in motivation thus leading to the heightened in-class exercising.The evidence that the application of the described experimental exercise programme had a positive effect on manual coordination, fine manual control and overall strength, implies that it can be applied to significantly improve the performance of younger populations with mild intellectual disabilities.

Conclusion
Our research study is in line with the global contemporary trends in the monitoring of the effects of various exercise programmes on the improvement of motor skills, components of physical fitness, and increased physical activity of children and youths with intellectual disabilities.The contribution of this research is reflected in the analysis and the explanation of the practical effects that a specially designed exercise programme can have on the motor proficiency of adolescents with mild intellectual disabilities.
Although the aforementioned study offers valuable insights into the impact of a 12-week manipulative skills exercise programme on the motor proficiency of young individuals with intellectual disabilities, it is important to acknowledge certain limitations.One such limitation is the small sample size, with only 32 participants divided into two groups.This limited sample size could restrict the generalisability of the findings and weaken the statistical power of the study.To enhance the reliability of the results, it would be advantageous to have a larger and more diverse sample.Also, the study involved a 12-week exercise programme, which may be considered relatively short for assessing long-term effects.It would be beneficial to conduct follow-up assessments after the intervention period to evaluate whether the improvements in motor proficiency are sustained over time.Addressing these limitations in future studies would enhance the validity, generalisability, and practical implications of the findings related to the effects of manipulative skills exercise programmes on motor proficiency in populations with intellectual disabilities.

Table 1
Manipulative skills intervention programme (The first 4 weeks of the exercise programme as a sample)