Effects of moderate-intensity aerobic exercise combined with acupuncture on attention function of mentally-retarded adolescents: a randomised controlled trial

LI Shuoqi,GUO Rong,LIU Chunjing,ZHAI Jiali,LI Keke,LI Shiming,YU Wenbing

LI Shuoqi,School of Health Science,Universiti Sains Malaysia,Kota Bharu 15100,Malaysia

GUO Rong,School of Foreign Languages,Ludong University,Yantai 264025,China

LIU Chunjing,Department of Physical Education,Qingdao Technical College,Qingdao 266400,China

ZHAI Jiali,School of Rehabilitation Medicine,Binzhou Medical University,Yantai 264003,China

LI Keke,LI Shiming,YU Wenbing,Laboratory of Sports and Human Sciences,Ocean University of China,Qingdao 266100,China

Abstract OBJECTIVE: To detect the impact of moderate-intensity aerobic exercise combined with acupuncture on the attention function of mentally-retarded adolescents from the three dimensions of attention concentration,attention transfer and attention span.METHODS: A total of 48 adolescents with mild to moderate mental disabilities were recruited.The participants were randomly divided into four groups:control group (C),Traditional Chinese Medicine acupuncture group (M),moderate-intensity aerobic exercise group (E) and exercise and acupuncture combined intervention group (J).Before and after the experimental intervention,the participant’s height,weight and attention ability were measured.RESULTS: The improved range of attention total duration of the J group after the intervention was significantly higher than that of the E and M groups (P ＜ 0.05),whereas that of the latter groups was significantly higher compared to that of the C group (P ＜ 0.05).The J group showed significantly higher (P ＜ 0.05) attention span values after the intervention compared to the E,M and C groups.The C group did not show a significant difference in attention transfer at 12 weeks compared to before intervention (P ＞ 0.05),whereas the E,M and J groups increased significantly (P ＜ 0.05) after intervention than the C group.CONCLUSIONS: Moderate-intensity aerobic exercise combined with acupuncture can more effectively improve the attention concentration and attention span of mentally-retarded adolescents than aerobic exercise or acupuncture alone.

Keywords: acupuncture;exercise;intellectual disability;adolescent;attention function;randomised controlled trial

1.INTRODUCTION

Adolescents often exhibit greater interference in visual selective attention tasks with mental retardation than those without such disorders with whom they share the same chronological age (CA).1-3Nevertheless,the nonmentally retarded participants were able to eliminate the interference at smaller separations between the target and distractor letters compared to the mentally-retarded participants.These events indicate group variations in the ability to restrict focal attention in the visual field.

Exercise may enhance concentration as adjuvant therapy for mental retardation.4-6Active participation in exercise and physical activities positively impacts concentration,inhibitory control,and reading and mathematics achievement.7Similarly,acupuncture treatment may also effectively improve the attention ability of mentallyretarded adolescents.Acupuncture has a practical history of more than 2000 years in China and is one of the vital modalities of treatment in Traditional Chinese Medicine(TCM).8Baihui (GV20) is the main acupoint from the Dumeridian that is believed to activate the spirit.Baihui(GV20) acupuncture treatment9was found to induce improved cognitive functions after 4 weeks (five times per week,30 min per time) in experimentally induced cerebral ischemia injuries in rodents.10,11

At present,there is data paucity on the impact of exercise combined with Traditional Chinese Medicine on mentally-retarded adolescents.This study aims to detect the impact of moderate-intensity aerobic exercise combined with acupuncture on the attention function of mentally-retarded adolescents from the three dimensions of attention concentration,attention transfer and attention span.

2.METHODS

2.1.Participants

A total of 48 adolescents with mild to moderate mental disabilities were recruited from Sanjiang special education school in Qingdao,Shandong province.The classification of mental disabilities was based on the b117 standard of intellectual function deficits in the framework of the international classification of functioning,disability and health child and youth (ICFCY).12All participants completed the intervention and test.

The inclusion criteria entailed：(a) Aged 12 to 18；(b)Participants were diagnosed with mild to moderate mental retardation by clinicians and Intelligent Quotient(IQ)=35 to 70；(c) No disease unsuitable for exercise.(d) Participants had normal vision and colour vision.All subjects have signed informed consent and passed the ethical review of the ethics committee of Ocean University of China (OUC-HM-2021-012).The experiments in the present study were performed following the Helsinki Declaration.G*power (Version 3.1.9.2,University of Trier,Trier,Germany) was used to compute the required sample size and the Post-hoc power(1-β err prob) was assumed as 0.90.

2.2.Study design

A single-blind randomised controlled trial was performed.An independent researcher carried out the random grouping.When the participants first came to the laboratory,they needed to draw lots in a blind box containing four kinds of “C”,“M”,“E” and “J” notes.The participants did not know the meaning of the grouping letters.According to the drawing of lots,the participants were randomly divided into four groups:control group (C),Traditional Chinese Medicine acupuncture group (M),moderate-intensity aerobic exercise group (E) and exercise and acupuncture combined intervention group (J).The physiotherapist and relevant researchers received the assignment list by email.Before the experimental intervention,the subject’s height,weight and attention ability were measured before performing the intervention three times a week.After 12 weeks of intervention,the above indexes were measured again within three days.

2.3.Intelligence assessment

The participant's IQ before and after exercise interventions were evaluated using a pre-validated Wechsler Intelligence Scale test.13,14IQ measurements of the participants ranged from normal (IQ=90-114) mild(IQ=50-70),and moderate (IQ=35-49) respectively.

2.4.Attention function test

An eye tracker (Tobii Pro spectrum,Tobii Pro,Stockholm,Sweden) and test software (Tobii Pro lab,version 1.162,Stockholm,Sweden) were used for the attention function test.15Random numbers were selected and provided to mentally-retarded adolescents for recognition.The test indicators comprise three main dimensions: (a) attention concentration;(b) attention span;(c) attention transfer.During the test,the room was kept quiet with the provision of adequate light.The participants sat in front of the computer,looked directly at the computer screen,and completed the test task by following the instructions and tips with assistance and guidance from the researcher.

For the attention focused test,participants were required to gaze at the target point of the task under other interference stimuli.The total time,average time and fixation times of the target were measured by the task eye tracker and programme.For the attention span test,participants were required to annotate as many observed objects in the target area as possible among the several numbers presented on the computer screen,and record the number of observed numbers in the target area.During the attention transfer test,participants were directed to follow the red arrow in the target gaze area to complete the task,transfer the attention target as soon as possible,and then record the accuracy of attention transfer.Figure 1 is a hot spot graph case of attention concentration,attention span and the attention transfer test.

Figure 1 Hot spot figure of attention function test.

2.5.Intervention

The M group used plum-blossom acupuncture for intervention,intervention three times a week for a total of 12 weeks.The first intervention entailed the use of a 95% concentration of medical alcohol to disinfect the electric plum needle,then the participant was asked to sit in a chair,ensuring that the back is straight and the body is relaxed.The researchers put the electric plum needle flat on the acupoint and beat the skin with the help of wrist force.Select a small force,that is,there is no obvious bleeding point at the acupoints,and the participants have no pain.The buckle under the electric plum needle automatically pops up after the intervention for 2 min each and tap frequency for 60 beats per minute.The protocol described in a previous study study16was performed by the exercise group.The exercise was performed on a treadmill three times a week for a total of 12 weeks.Prior to the formal exercise,participants wore a heart rate band (Polar H10) and warmed up for 5 min at 5 km/h,followed by 45 min of moderate sustained exercise at the target intensity of 65% to 75% maximum heart rate (HRmax) (HRmax=220-age).Then,the exercise heart rate was recorded every 15 min,rating of perceived exertion (RPE).The recovery movement was also carried out at a speed of 5 km/h after the exercise.The J group needed to implement the treatment plan of the exercise group immediately after the completion of the intervention in the same form,whereas the C group maintained their original lifestyle for 12 weeks without any intervention.

2.6.Statistical analysis

G-Power software was employed to determine the required sample size.Data were subjected to the Shapiro-Wilk normality test and the results showed that all variables conformed to the conditions of normal distribution.Differences in the transfer,span,average duration,total duration,maximum duration and attention times between various time points and across groups were determined using repeated measures two-way analysis of variance(ANOVA).The least significant difference test was applied for the Post-hoc ANOVA analysis to identify the simple main effects when a significant interaction was present.All the values were reported as mean ± standard deviation and statistical significance were set atP ＜0.05.

3.RESULTS

3.1.Participants

Participants’ physical characteristics of each group are shown in Table 1.All participants were congenitally mentally-retarded.There was no significant difference in height,weight,and HRmaxacross the four groups (P ＞0.05).Likewise,the average HR and RPE were not significantly different across the E group and J group(P ＞0.05).Figure 2 provides an overview of the study design.

Table 1 Participants’ Physical characteristics and average heart rate and rating of perceived exertion during exercise

3.2.Attention concentration

Appendix shows the pre-and post-intervention attention concentration variables of the four groups,and the findings from the two-way ANOVA repeated measures.No significant differences were observed in the initial values of attention variables before intervention (P ＞0.05).However,after 12 weeks of intervention,the total duration of attention in the E group and J group was significantly higher (P ＜0.05) than the initial values.The M group and C group did not show any significant difference in the total duration of attention concentration between 12 weeks and before intervention (P ＞0.05).As shown in Figure 3,the improved range of the J group after the intervention was significantly higher than that of the E and M groups (P ＜0.05),whereas that of the latter groups was significantly higher compared to that of the C group (P ＜0.05).After 12 weeks of intervention,there was no statistical difference in the average duration of attention in all groups compared with before intervention (P ＞0.05).No significant difference was detected in the amplitude of change among all groups (P ＞0.05).Furthermore,the maximum duration of attention in the J group was significantly higher than the initial values after 12 weeks of intervention (P ＜0.05).There was no significant difference in the maximum duration of attention concentration in the E group,M and group C based on the comparison at 12 weeks and before intervention (P ＞0.05).Compared to the E,M and C groups,the improvement of the J group after the intervention was significantly higher (P ＜0.05).

Figure 2 Distribution of study participants

Figure 3 Scatter plot of the difference between the duration of attention before and after intervention in each group

4.DISCUSSION

This study explored how the attention function of mentally-retarded adolescents is affected by moderateintensity aerobic exercise.According to Alghadiret al,16exercise intervention with the intensity of 65% to 75%HRmaxfor adolescents with mild to moderate mental retardation aged 12-18 is safe and effective.The present study focused on whether the combination of Chinese acupuncture will improve the attention function of mentally-retarded adolescents.After the intervention,the results showed that the improvement in the attention concentration and attention span of mentally-retarded adolescents in group J was better than those in groups E and M.Nevertheless,the three groups had similar effects on the improvement of attention span.These findings revealed that moderate-intensity aerobic exercise may achieve a better intervention effect combined with Traditional Chinese Medicine acupuncture,and has the potential to become a new adjuvant treatment for mentally-retarded adolescents.

A previous study demonstrated that exercise therapy effectively ameliorates symptoms or medication dose in adolescents with deficit hyperactivity disorder who were already stabilised on medication.17These findings are in line with the results obtained from the present study.Additionally,Went18also supported the improvement in inattentiveness as therapeutic movement protocol facilitated a positive shift in the concentration among subjects with attention deficit hyperactivity disorder.Exercises were suggested to play a vital role in the classroom by resolving attention and learning challenges.19Milleret al,20also reported that the likelihood of having pupils with higher concentration levels was higher among schools offering a more intense physical activity programme.Despite the participants in the above study are not mentally-retarded teenagers,from the effect of other groups,they could also support the effect of exercise on the improvement of attention function to a certain extent.The positive impacts of this exercise mode might be explained by the effects of the increased sympathetic system.21,22Given that exercise induces physical stress,activates both the sympathetic system and the hypothalamic-pituitary-adrenal (HPA)axis,23these events might contribute to positive effects of aerobic exercise on cognitive function.Cognitive function has also been shown to be influenced by cortisol and noradrenaline;stress hormones responsible for the activation of the HPA axis and the sympathetic system.24,25

In addition to exercise,acupuncture may also be an effective auxiliary programme to improve the attention function of mentally-retarded adolescents.26According to Traditional Chinese Medicine theory,the intersection of the line connecting the apexes of the two auricles and the midsagittal line of the head marks the location of a vital acupoint,Baihui (GV20).Psychiatric and neurological disorders such as dizziness,headache,stroke,and anxiety have been treated using Baihui (GV20)27A few studies have reported that stimulation that combines Baihui (GV20) with other acupoints improved mental states.28Some recent studies also show that moxibustion at Baihui (GV20) can also improve the attention function of patients with mild cognitive impairment29and insomnia attention deficit.30However,there is limited knowledge regarding the enhancement of attention function induced by stimulation at Baihui (GV20).In this study,electric plum-blossom needle was used for intervention.The electric plum-blossom needle is able to objectively and quantifiably set stimulation frequency and intensity.31Moreover,due to the electric plumblossom needles is easy to operate,it is more convenient to be applied in the family rehabilitation of mentallyretarded adolescents.These properties offer more advantages in the application of electric plum-blossom needles in acupuncture research.

This study revealed that moderate-intensity aerobic exercise combined with acupuncture is better than the single-use of aerobic exercise or acupuncture to improve the attention concentration and attention span of mentally-retarded adolescents.It suggests that the combination of exercise and acupuncture may produce superposition effects,thereby improving the intervention effect.However,the limitations of this study are wellacknowledged.Firstly,due to the rapid growth and development of children,the age span of the participants selected in this study is relatively large.Secondly,the number of participants in the intervention is small,thus future studies might consider larger sample research.Furthermore,the physiological mechanism of acupuncture and moxibustion improving attention function is not clear.Although many research teams are exploring the physiological mechanism of acupuncture and moxibustion effect,there is no clear certainty at present.Finally,it should be noted the materials in the functional test scheme are relatively single and only numbers.Different test materials can be added for testing in future research,such as different pictures or different colours.

In conclusion,moderate-intensity aerobic exercise combined with acupuncture can more effectively improve the attention concentration and attention span of mentally-retarded adolescents than aerobic exercise or acupuncture alone.