研究目的:

注意缺陷多动障碍(Attention deficit and hyperactivity disorder, ADHD)，是儿 童期常见的神经发育障碍之一。37.9%的 ADHD 儿童共患学习困难，其中书写障 碍占 65%，不仅严重影响儿童的学业成绩，还会损害其自尊及生活质量。此外， 30-80%的 ADHD 儿童伴有动作技能发展落后，伴动作落后的患儿核心症状和功 能损害更严重，预后也更差。已有研究证实，运动可缓解 ADHD 儿童的核心症 状，促进其动作技能发展。作为一种典型的精细动作技能，书写技能是否与患儿 的核心症状相关，不同年龄、亚型的 ADHD 儿童书写技能是否相同?书写技能 落后的神经机制如何?根据书写技能落后特征制定的针对性运动干预是否可提 高书写技能?有关上述问题的研究尚未见报道，有必要对此展开研究。

本研究旨在探析 ADHD 学龄男童书写技能的总体表现和年龄、亚型特点， 探究其书写技能的神经机制特点，并探索 ADHD 学龄男童针对性运动干预方案 的制定及实施效果，以期为开展 ADHD 儿童书写技能的精准运动干预提供理论 依据和方法借鉴。

研究方法:

在 2021 年 3 月—2023 年 7 月期间，从北京市某三甲精神专科医院门诊招募 学龄期初诊的 ADHD 学龄男童 55 名，并采用简明儿童青少年国际精神访谈儿童 版从北京市某公立小学 1-4 年级学生完成初筛，再由 2 名高年资精神科专科医生 采用临床诊断性会谈量表和儿童情感障碍和精神分裂症问卷进行深入评估，结合 韦氏儿童智力量表第四版筛查出符合美国《精神障碍诊断与统计手册(第 5 版)》 诊断标准的 37 名 ADHD 男童，最终研究共纳入 6-10 岁 ADHD 男童 92 名，年 龄 6.76-10.95 岁，平均年龄 8.47±1.17 岁，其中注意缺陷型(predominately inattentive type, ADHD-I)男童 60 名，混合型(combined type, ADHD-C)男童 32 名，同时从某 公立小学按照年龄不超过半岁招募正常男童 83 名(年龄 6.82-10.92 岁，平均年龄 8.42±1.10 岁)作为对照组。所有被试家长均签署知情同意书。

使用曾氏书写检查表、书写评估工具以及儿童动作协调能力标准工具来评估 全部学龄男童书写技能，采用注意缺陷/多动障碍评定量表、执行功能行为评定量 表(Behavior Rating Inventory of Executive Function，BRIEF)和 Stroop 色词、Ray 复杂图形、连线测试来分别评估 ADHD 男童核心症状和执行功能。采用独立样

本 T 检验、单因素方差分析分别比较不同年龄、不同亚型男童的组间差异，采用 Spearman 轶相关分析探讨 ADHD 学龄男童书写技能与其核心症状之间的相关关 系，并采用偏差校正的非参数百分位 Bootstrap 法验证 ADHD 学龄男童执行功能 在其书写技能与核心症状之间的中介效应。

使用 Delsys 无线表面肌电仪和 NIRSport 便携式近红外成像仪分别采集学龄 男童在描画轨迹、书写汉字“三川八”、阿拉伯数字“0-9”、大小写英文字母“A- Z”等任务时拇短展肌、第一背侧骨间肌、桡侧腕屈肌和指伸肌的肌电信号及前 额叶大脑皮层血液动力学变化。肌电测试中，选择某肌肉的平均肌电值占所测全 部肌肉平均肌电值总和的百分比和差异性系数来评价肌肉贡献率和肌肉用力一 致性。近红外测试中选择氧合血红蛋白 β 值评定大脑皮层神经元激活水平。采用 独立样本 T 检验及单因素方差分析进行不同年龄、不同亚型组间比较，显著性水 平设为 α=0.05。

从募集的 ADHD 学龄男童中选取 78 名(年龄 8.10-10.90 岁，平均年龄 9.65±1.06 岁，其中 ADHD-I 型男童 38 名，ADHD-C 型男童 40 名)，随机分为干 预组和等待组各 39 例，同时按照年龄相差不超过半岁匹配正常儿童 35 名作为对 照组。针对提高视觉感知、执行和肌肉控制能力，制定整合多种粗大及精细动作 的游戏化运动干预方案，干预组接受为期 8 周，每周 3 次(1 次线下，2 次线上)， 每次 60 分钟的针对性游戏化运动干预，等待组和正常对照组参与一般性的身体 活动，干预第二周从三组中分别随机选取 6 名男童，在线下运动干预前给运动干 预组男童佩戴 Antigraph 三维能耗仪，其他组男童要求完整佩戴一个周期的时间， 计算其体力活动总量。使用配对样本 T 检验分别比较三个组自身干预前后书写 技能的变化差异，采用协变量方差分析比较干预后三个组的差异，显著性水平设 为 α=0.05。

研究结果:
1. ADHD 学龄男童书写技能表现测试结果。
本研究选取 ADHD 男童年龄 6-10 岁，测试显示 ADHD 男童曾氏书写量表

得分高于正常男童(P<0.01)，字母可读性、单词可读性及数字可读性低于正常男 童(P<0.01)。不同年龄段中，6-8 岁低龄 ADHD 男童曾氏书写检查表得分高于同 龄正常男童(P<0.01)，字母可读性、单词可读性以及数字可读性低于同龄正常男 童(P<0.01);9-10 岁高龄 ADHD 男童曾氏书写量表得分及单词可读性低于同龄正 常男童(P<0.01)。不同亚型来看，ADHD-I 和 ADHD-C 男童在曾氏书写量表得分 和字母、单词可读性上均落后于正常男童(P<0.01);在数字可读性上，ADHD-I 男 童低于正常儿童(P<0.05)，而 ADHD-C 男童与正常男童的得分没有统计学差异 (P>0.05)。ADHD 学龄男童监控功能在惯用手插钉与注意缺陷核心症状之间的中

介效应显著(β=-0.366，P<0.01);多重中介效应显示，非惯用手插钉显著负向预测 注意缺陷核心症状，且监控因子的中介效应显著，占中介效应量的 64.64%。

2. ADHD 学龄男童书写技能神经控制相关测试结果。

视知觉能力测试显示 ADHD 学龄男童五项测试项目的得分均低于正常男童 (P<0.05);低龄 ADHD 男童视知觉各项能力得分均落后于同龄正常男童(P<0.01)， 高龄 ADHD 男童手眼协调得分落后于同龄正常男童(P<0.01);ADHD-I 和 ADHD- C 男童在手眼协调和仿绘这两项上的得分均低于正常男童(P<0.01);且 ADHD-I 组男童视觉辨别的得分低于正常男童，差异具有显著性(P<0.05)，ADHD-C 男童 与正常男童不存在统计学差异(P>0.05)。

近红外测试显示 ADHD 学龄男童书写汉字时背外侧前额叶通道 β 值低于正 常男童(P<0.05)，在进行描画轨迹及书写英文字母时前额叶通道 β 值与正常男童 没有统计学差异(P>0.05);低龄 ADHD 男童描画轨迹时，右背外侧前额叶通道 β 值高于同龄正常男童(P<0.05)，书写汉字时，右腹外侧前额叶通道 β 值低于同龄 正常男童(P<0.05);高龄 ADHD 男童描画轨迹时，右眶额叶通道 β 值高于同龄正 常男童(P<0.05)，书写英文时，右背外侧前额叶通道 β 值高于同龄正常男童 (P<0.05)。ADHD-I 男童描画轨迹时，右背外侧前额叶通道 β 值高于正常男童 (P<0.05)，书写汉字时右腹外侧前额叶通道 β 值低于正常男童(P<0.05);ADHD-C 男童描画轨迹时，左腹外侧前额叶通道 β 值低于正常男童(P<0.05)，书写英文时 背外侧前额叶通道 β 值高于正常男童(P<0.05)。

肌电测试显示 ADHD 学龄男童在进行描画轨迹任务时惯用手第一背侧骨间 肌的肌肉贡献率大于正常男童的值(P<0.05)。低龄 ADHD 男童书写英文字母时， 拇短展肌肌肉贡献率高于正常男童(P<0.05);在描画轨迹任务时，惯用手指伸肌 肌肉贡献率低于正常男童(P<0.05);高龄 ADHD 男童在书写阿拉伯数字时，非惯 用手指伸肌肌肉贡献率低于同龄正常男童(P<0.05)。ADHD-C 型男童在书写英文 字母时惯用手拇短展肌和第一背侧骨间肌的肌肉贡献率均大于 ADHD-I 男童 (P<0.05);非惯用手桡侧腕屈肌和非惯用手指伸肌肌肉贡献率均小于 ADHD-I 型男童和正常男童(P<0.001)。在书写汉字时，ADHD-C 男童非惯用手指伸肌肌肉贡 献率小于 ADHD-I 和正常男童肌肉贡献率(P<0.01，P<0.05)。在描画轨迹时， ADHD-C 男童非惯用手指伸肌、非惯用手桡侧腕屈肌肌肉贡献率均小于 ADHD- I 和正常男童肌肉贡献率(P<0.01)。ADHD 儿童五种书写任务过程中各肌肉差异 性系数高于 100%，最高 279%，正常儿童数值范围在 50-100%。低龄 ADHD 男 童肌肉差异性系数范围在 74%-288%，高龄 ADHD 男童肌肉差异性系数在 70%- 427%;ADHD-I 男童肌肉差异性系数范围在 64%-382%，ADHD-C 男童肌肉差异 性系数最高达 421%。

3. ADHD 学龄男童运动干预前后书写技能和核心症状的比较结果。

制定针对提高视觉感知、执行和肌肉控制能力、包含不同难度的粗大及精细 动作的游戏化运动干预方案。实施 8 周后，ADHD 干预组曾氏书写检查表得分比 干预前降低(P<0.01)，数字、字母、单词可读性与干预前相比，均提高(P<0.01); ADHD 干预组注意缺陷得分、多动/冲动得分以及核心症状总分与干预前相比， 均下降(P<0.01)。运动干预后 ADHD 干预组的书写量表得分低于 ADHD 等待组 得分(P<0.05);且与正常对照组没有统计学差异(P>0.05);ADHD 干预组运动干 预后的单词、字母、数字可读性均高于 ADHD 等待组(P<0.05)，且在字母可读性 上高于正常对照组(P<0.05)。ADHD 干预组运动干预后的注意缺陷得分、多动/冲 动得分以及核心症状总分均低于 ADHD 等待组得分(P<0.05)，且与正常对照组没 有统计学差异(P>0.05)。

研究结论:

1. ADHD 学龄男童书写技能落后。不同年龄、不同亚型 ADHD 男童书写技 能落后特征不同，低龄男童书写技能全面落后，高龄男童在高难度书写任务上表 现落后;与混合型男童相比，注意缺陷型男童书写技能全面落后。6-10 岁 ADHD 学龄男童的书写技能与其核心症状相关，监控功能在两者之间起中介作用。

2. ADHD 学龄男童书写技能落后的机制涉及视觉信息整合缺陷、空间认知脑 区激活不足、书写技能相关肌肉分配的协调性及控制的稳定性不良等多环节信息 加工能力落后，神经发育落后呈现广泛性、不均衡性、不典型性的特征。不同年 龄、不同亚型 ADHD 男童书写技能落后的神经机制呈现异质性。

3. 为期 8 周、每周 3 次、每次 60 分钟、针对提高视觉感知、执行和肌肉控 制能力、包含不同难度的粗大和精细动作的综合运动干预，可显著提高 6-10 岁 ADHD 学龄男童的书写技能，有效缓解其核心症状。

Attention deficit hyperactivity disorder (ADHD) is one of the common

neurodevelopmental disorders in childhood. 37.9% of children with ADHD also suffer from learning difficulties, among which 65% have writing difficulties. This not only severely affects children’s academic performance but also damages their self-esteem and quality of life. Moreover, 30-80% of children with ADHD have motor skill development delays, and those with accompanying motor delays have more severe core symptoms and functional impairments, with a poorer prognosis. Previous studies have confirmed that physical activity can alleviate the core symptoms of ADHD children and promote their motor skill development. As a typical fine motor skill, is handwriting skill related to the core symptoms of children with ADHD? Are the handwriting skills of ADHD children of different ages and subtypes the same? What are the neural mechanisms underlying handwriting skill deficits? Can targeted motor interventions based on handwriting skill deficits improve handwriting skills? There have been no reports on the above issues, so it is necessary to conduct research in this area.

This study aimed to analyze the overall performance of handwriting skills in school-aged boys with ADHD, explore the characteristics of their handwriting skills in terms of age and subtype, investigate the neural mechanisms of their handwriting skills, and explore the development and implementation effects of targeted motor intervention programs for school-aged boys with ADHD. The objective is to provide an objective theoretical basis for the formulation of motor intervention programs, provide theoretical basis and method references for precise motor intervention for handwriting skills in 

children with ADHD.

Methods:
Between March 2021 and July 2023, 55 school-aged boys with initial diagnosis of

ADHD were recruited from the outpatient department of a tertiary psychiatric hospital in Beijing, and a preliminary screening was conducted using the Kiddie Schedule for Affective Disorders and Schizophrenia for School-Age Children. Then, two experienced child psychiatrists used the clinical diagnostic interview scale and the Child Emotional Disorder and Schizophrenia Questionnaire for in-depth evaluation, combined with the Wechsler Intelligence Scale for Children Fourth Edition to screen out 37 boys with ADHD who met the diagnostic criteria of the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders (5th Edition). A total of 92 school-aged boys with ADHD aged 6-10 years old were finally included in the study, with an average age of 8.47±1.17 years old, including 60 boys with predominantly inattentive type (ADHD-I) and 32 boys with combined type (ADHD-C). At the same time, 83 typically developing boys were recruited from a public primary school as a control group, with ages ranging from 6.82 to 10.92 years old and an average age of 8.42±1.10 years old. Informed consent was obtained from all parents of the participants.

The Chinese Handwriting Assessment, movement assessment battery for children and the Children’s Motor Coordination Test were used to evaluate the handwriting skills of all school-aged boys. The ADHD Rating Scale, the Behavior Rating Inventory of Executive Function, and the Stroop Color-Word Test, the Rey Complex Figure Test, and the Line Tracing Test were used to assess the core symptoms and executive functions of boys with ADHD, respectively. Independent sample t-tests and one-way ANOVA were used to compare the differences between different age groups and subtypes of boys, and Spearman’s rank correlation analysis was used to explore the correlation between handwriting skills and core symptoms in school-aged boys with ADHD. The bias-corrected percentile bootstrap method was used to verify the mediating effect of executive function on handwriting skills and core symptoms in school-aged boys with ADHD.

Delsys Wireless Surface EMG and NIRSport Near-Infrared Imaging were used to collect electromyographic signals from the abductor pollicis brevis, first dorsal interosseous muscle, flexor carpi radialis, and extensor digitorum during drawing 

trajectories, writing Chinese characters “San Chuan Ba”, Arabic numerals "0-9", and "A-Z" uppercase and lowercase letters tasks in school-aged boys, as well as changes in the hemodynamic responses of the prefrontal cortex. Independent sample t-tests and one-way ANOVA were used for between-group comparisons of different age groups and subtypes, with a significance level set at α=0.05.

Seventy-eight boys with ADHD (aged 8.10-10.90 years old, mean age 9.65±1.06 years old, including 38 boys with ADHD-I and 40 boys with ADHD-C) were randomly assigned to intervention and waiting groups, with 39 cases in each group, and 35 typically developing boys matched for age within half a year were recruited as a control group. A gamified motor intervention program integrating various gross and fine motor activities was developed to improve visual perception, executive function, and muscle control. The intervention group received targeted gamified motor interventions three times a week for 8 weeks (once offline and twice online), while the waiting group and the normal control group participated in general physical activities. In the second week of the intervention, six boys from each group were randomly selected to wear the Antigraph three-dimensional energy expenditure monitor before the offline motor intervention. The total amount of physical activity was calculated. Paired sample t-tests were used to compare the changes in handwriting skills before and after the intervention in each group, and covariance analysis was used to compare the differences among the three groups after the intervention, with a significance level set at α=0.05.

Results:

1. Performance of Handwriting Skills in School-aged Boys with ADHD

In this study, ADHD boys aged 6-10 years old were selected for testing. The results showed that the scores of the Chinese Handwriting Assessment for ADHD boys were higher than those for normal boys (P<0.01), while the legibility of letters, words, and numbers was lower than that for normal developing boys (P<0.01). In different age groups, ADHD boys aged 6-8 years scored higher on the Chinese Handwriting Assessment than normal boys of the same age (P<0.01), but their letter legibility, word legibility, and number legibility were lower than those of normal boys of the same age (P<0.01); ADHD boys aged 9-10 years scored lower on the Chinese Handwriting Assessment and word legibility than normal boys of the same age (P<0.01). In terms of different subtypes, both ADHD-I and ADHD-C boys scored lower on the Chinese Handwriting Assessment and letter and word legibility than normal boys (P<0.01); in terms of number legibility, ADHD-I boys scored lower than normal children (P<0.05), 

while there was no statistical difference in scores between ADHD-C boys and normal boys (P>0.05). The mediating effect of monitoring function in school-aged boys with ADHD between preferred hand peg insertion and core symptoms of attention deficit was significant (β=-0.366, P<0.01); multiple mediating effects showed that non- preferred hand peg insertion significantly negatively predicted core symptoms of attention deficit, and the mediating effect of the monitoring factor was significant, accounting for 64.64% of the mediating effect size.

2. Neurocontrol-related Test Results of Handwriting Skills in School-aged Boys with ADHD.

Visual perceptual ability testing showed that the scores of the five test items for ADHD school-aged boys were lower than those for normal boys (P<0.05); in particular, the visual perceptual abilities of younger ADHD boys were lower than those of same- age normal boys (P<0.01), and the hand-eye coordination scores of older ADHD boys were lower than those of same-age normal boys (P<0.01). Both ADHD-I and ADHD- C boys scored lower than normal boys on hand-eye coordination and imitation drawing (P<0.01); additionally, the visual discrimination scores of ADHD-I boys were lower than those of normal boys, with significant differences (P<0.05), while there was no statistical difference in scores between ADHD-C boys and normal boys (P>0.05).

Near-infrared testing showed that the β value of the right dorsolateral prefrontal cortex in ADHD school-aged boys was lower than that in normal boys when writing Chinese characters (P<0.05), but there was no statistical difference in β value during drawing trajectories and writing English letters (P>0.05). Specifically, during drawing trajectories, the β value of the right dorsolateral prefrontal cortex was higher than that of same-age normal boys (P<0.05) for younger ADHD boys, but it was lower than that of same-age normal boys when writing Chinese characters (P<0.05); for older ADHD boys, the β value of the right orbitofrontal cortex was higher than that of same-age normal boys (P<0.05) during drawing trajectories, and it was higher than that of same- age normal boys when writing English letters (P<0.05). For ADHD-I boys, the β value of the right dorsolateral prefrontal cortex was higher than that of normal boys during drawing trajectories (P<0.05), but it was lower than that of normal boys when writing Chinese characters (P<0.05); for ADHD-C boys, the β value of the left orbitofrontal cortex was lower than that of normal boys during drawing trajectories (P<0.05), but it was higher than that of normal boys when writing English letters (P<0.05).

Electromyographic testing showed that the muscle contribution rate of the first 

dorsal interosseous muscle of the preferred hand was greater in ADHD school-aged boys during drawing trajectory tasks than in normal boys (P<0.05). Specifically, for younger ADHD boys, the muscle contribution rate of the abductor pollicis brevis muscle was higher than that of normal boys when writing English letters (P<0.05); during drawing trajectory tasks, the muscle contribution rate of the extensor digitorum muscle was lower than that of normal boys (P<0.05); for older ADHD boys, the muscle contribution rate of the non-preferred hand extensor digitorum muscle was lower than that of same-age normal boys when writing Arabic numerals (P<0.05). For ADHD-C boys, the muscle contribution rates of the preferred hand abductor pollicis brevis muscle and first dorsal interosseous muscle were both greater than those of ADHD-I boys (P<0.05); the muscle contribution rates of the non-preferred hand flexor carpi radialis muscle and non-preferred hand extensor digitorum muscle were both lower than those of ADHD-I boys and typically developing boys (P<0.01). When writing Chinese characters, the muscle contribution rate of the non-preferred hand extensor digitorum muscle in ADHD-C boys was lower than that in ADHD-I boys and normal boys (P<0.01, P<0.05). During drawing trajectories, the muscle contribution rates of the non-preferred hand extensor digitorum muscle and non-preferred hand flexor carpi radialis muscle in ADHD-C boys were both lower than those in ADHD-I boys and typically developing boys (P<0.01). The coefficient of variation for muscle activity in ADHD children during the five handwriting tasks exceeded 100%, with a maximum of 279%, while the range for normal children was 50-100%. The coefficient of variation for muscle activity in younger ADHD boys ranged from 74% to 288%, and in older ADHD boys it ranged from 70% to 427%; for ADHD-I boys, the coefficient of variation for muscle activity ranged from 64% to 382%, and for ADHD-C boys, it reached a maximum of 421%.

3. Comparison Results of Handwriting Skills and Core Symptoms Before and After Motor Intervention in School-aged Boys with ADHD

A gamified motor intervention program was developed targeting the improvement of visual perception, executive function, and muscle control abilities, integrating various gross and fine motor activities. After 8 weeks of implementation, the scores of the Chinese Handwriting Assessment for the ADHD intervention group decreased compared to before the intervention (P<0.01), while the legibility of numbers, letters, and words all improved compared to before the intervention (P<0.01). The scores for attention deficit, hyperactivity/impulsivity, and total core symptoms for the ADHD intervention group all decreased compared to before the intervention (P<0.01). 

After motor intervention, the Chinese Handwriting Assessment scores for the ADHD intervention group were lower than those for the ADHD waiting group (P<0.05), and there was no statistical difference compared to the normal control group (P>0.05). Additionally, the word, letter, and number legibility for the ADHD intervention group after motor intervention were all higher than those for the ADHD waiting group (P<0.05), and the letter legibility was higher than that of the normal control group (P<0.05).

The scores for attention deficit, hyperactivity/impulsivity, and total core symptoms for the ADHD intervention group after motor intervention were all lower than those for the ADHD waiting group (P<0.05), and there was no statistical difference compared to the normal control group (P>0.05).
Conclusions:

1. Handwriting skills in school-aged boys with ADHD are lagging behind. Different age groups and subtypes of ADHD boys exhibit different characteristics of handwriting skill deficits. Younger ADHD boys generally lag behind in overall handwriting skills, while older boys with ADHD show deficits in more challenging writing tasks. Compared to ADHD-C boys, boys with the inattentive subtype of ADHD generally exhibit comprehensive deficits in handwriting skills. The handwriting skills of ADHD school-aged boys aged 6-10 are correlated with their core symptoms, with monitoring function playing an intermediary role between the two.

2. The mechanisms underlying the deficits in handwriting skills in school-aged boys with ADHD involve deficiencies in multiple aspects: integration of visual information, inadequate activation of spatial cognitive brain regions, lack of coordination and stability in muscle distribution related to handwriting skills of information processing abilities in multiple links. These deficits manifest as widespread, unbalanced, and atypical features of neurodevelopment. The neurobiological mechanisms underlying handwriting skill deficits vary heterogeneously across different ages and subtypes.

3. A comprehensive motor intervention program lasting 8 weeks, with sessions held 3 times per week for 60 minutes each, targeting the improvement of visual perception, executive function, and muscle control abilities, incorporating various levels of gross and fine motor activities, significantly enhances handwriting skills in school-aged boys with ADHD aged 6-10. It also effectively alleviates their core symptoms.