WHO recommended that the duration of physical activities in children and youths aged 5–17 years old should be a minimum of 60 min of moderate to vigorous tasks per day and that this could be divided into short bouts throughout the day. Whenever possible, children and youth with disabilities should meet these recommendations [30]. All participants in the current study did not meet these WHO recommendations.
Although the activity rate of the children with deafness in this study was slightly higher than that of the children with blindness, this did not reach statistical significance (p = 0.06). These results were in contrast with the findings reported by Engel-Yeger and Hamed-Daher [31], who detected significant differences in the activity performance between children with HI and VI; children with VI performed fewer activities than children with HI. This lack of consensus in the literature regarding activity rate might be due to the different physical activity assessment methods used in these studies.
In this study, when comparing children with HI to sighted-hearing children regarding their step rate and activity rate, significant differences were noticed in favor of children with HI (p = 0.05 and 0.003 respectively). In general, children with HI had lower sedentary time and higher time in light and moderate activities than their sighted-hearing peers (p = 0.004, 0.004, and 0.02 respectively). No significant differences were recorded between the three groups with respect to the total vigorous activity time. Our study results were consistent with the outcomes from the work of Longmuir and Bar-Or [32], where children with HI were considered to be more fit or as fit as sighted-hearing children. Gispen et al. [33] found that adults with HI had less physical activities than adults without HI. These differences in physical activity parameters between the group with HI and the sighted-hearing group might be due to the different age groups in the research.
In addition, all children in this study were at school during physical activities assessment, and this could be the reason why all children spent most of their time in sedentary activities, with the percentages of total sedentary time between 60.18 ± 10.62 and 67.93 ± 6.96. These results were consistent with a study done by Sit et al. [34], which reported that children spent more than 70% of their overall time at school being sedentary.
However, the current research showed that children with VI spent more time in sedentary activities compared with children with HI (65.73 ± 6.24% in VI vs. 60.18 ± 10.62% in HI, p = 0.03). Our findings are consistent with those reported by Longmuir and Bar-Or [32]. These authors found that most youths with VI had relatively limited participation in physical activity compared to children with HI. Sit et al. [34] reported that children with VI were more active and spent less time sedentary than children with other disabilities, including HI. These conflicting findings might be due to the variety of lifestyle characteristics in the school system in Hong Kong, where the Education Bureau recommends that 5–8% of the total school curriculum time be allocated to daily active physical education.
Also, children with HI showed better sleep efficiency, less wake time after sleep onset, and a lower awaking rate when compared to the control group. However, no significant differences were reported for sleep parameters when comparing children with VI and sighted-hearing children, nor when comparing children with VI and children with HI.
Dursun et al. [35] investigated the effect of ice skating on the sleep quality in children with VI and HI using the Pittsburgh Sleep Quality Index (PSQI) questionnaire. These authors found that children with HI had poorer sleep quality than children with VI before and after the ice skating program. These controversial results in sleep quality might be due to the different quality of sleep assessment methods.
A study on toddlers with VI by Fazzi et al. [20] also showed that in the first years of life, children with VI had increased risk for a specific sleep disorder compared with their sighted peers. In addition, Davitt et al. [36] studied sleep disorders in children with congenital Anophthalmia and Microphthalmia and found that children with VI had more sleep disorders compared to sighted-hearing children. These controversial results in sleep quality of VI children might be due to the difference in sleep assessment methods and/or the difference in age of the involved children.
Limitations
The current study has some limitations. First, the sample in this study was a convenience sample of children with sensorineural deafness and blindness which might encourage bias. Second, the current study was unblinded, which might also introduce bias. Third, all participants were recruited only from schools in the Eastern Province and this could affect the generalizability of the obtained results to the whole Kingdom. Therefore, the results of the study should not be generalized, except with great caution. Last, the physical activity evaluation via the ActiGraph accelerometer was assessed for only 4 days; the results might have been more representative if this had been done for 7 days.