CHAPTER 7 FINE MOTOR SKILL DEVELOPMENT IN INFANTS AND CHILDREN Jin Bo & Jane E. Clark

Fine motor skill: generally refers to those motor skills produced predominantly by the smaller muscles or muscle groups of the body.

§7.1 REACHING AND GRASPING §7.2 DEVELOPMENT OF TOOL USE §7.3 DEVELOPMENT OF DRAWING §7.4 DEVELOPMENT OF HANDWRITING §7.5 DEVELOPMENT OF BIMANUAL COORDINATION §7.6 APPROACHES TO STUDY THE DEVELOPMENT OF HAND-EYE COORDINATION §7.7 SUMMARY

§7.1 REACHING AND GRASPING Development of the Grasp grasp reflex ： voluntary, adaptive behaviors

Development of Reaching  pre-reaching: The movements are quick and ballistic extensions that usually miss the target.  successful reaching: Jerky following a zig-zag trajectory. Depending on online visual feedback

skillful reaching: They can make more accurate, smooth arm movement trajectories and coordinate their reaching and grasping. In this period, visual feedback can be used but is not necessary.

§7.2 DEVELOPMENT OF TOOL USE  Development of Tool Use – Spoon anticipate the spoon’s arrival by opening their mouth Reach for the spoon during eating, tend to press their lips to remove the food from the spoon anddraw back their head Manipulate a spoon in various ways Feed themselves Developmental grip patterns Passively when they are fed

Development of Tool Use – Chopsticks  Wong and colleagues (2002) defined the average age of using chopsticks to finish most of a Chinese meal was 4.6 years

Development of Tool Use - Holding a Writing Implement  palmer grasp (power grip )  the roles of thumb and fingers are differentiated The mature grasp dynamic tripod

§7.3 DEVELOPMENT OF DRAWING scribbling stage combine stage aggregate stage pictorial stage  it is difficult to set age-related norms  experience is One of the most important factors affecting the drawing development of the child’s

§7.4 DEVELOPMENT OF HANDWRITING Hamstra-Bletz and Blote (1990) : Thirteen characteristics of handwriting were clustered into different aspects: development of fine motor ability stylistic preference structural performance  temporal and spatial characteristics of the children’s movements  dysgraphia

 Development of Handwriting – Chinese Writing Chinese characters (HanZi) is unique and more complex than writing English letters.  two challenge for Chinese writing : sequencing spatial configuration

Recognizing a Chinese character is considered much more important than learning how to write Chinese before the elementary age. less-stroke characters more- less-stroke characters

It is hard to determine the age- related norms for Chinese handwriting since this type of skill is highly influenced by the environment such as opportunities for practice and teaching methods.

§7.5 DEVELOPMENT OF BIMANUAL COORDINATION  symmetrical bimanual coordination : both hands with similar and simultaneous patterns  For example: the Moro reflex

 asymmetrical bimanual coordination :Other bimanual movements require different roles for the two hands  a mirror image movement / a parallel movement  symmetrical bimanual coordination /asymmetrical bimanual coordination  hands at the same velocity /at different velocities

 primary manipulator : The hand that is manipulating the object  complementary manner : the other hand that is used to stabilize the object  For example: the Moro reflex

§7.6 APPROACHES TO STUDY THE DEVELOPMENT OF HAND-EYE COORDINATION control system perspective feedback:a process whereby sensory information arising from the body is fed back to the brain closed-loop systems

输入 执行 效应器 输出 比较器 实际状态 错误反馈 反馈 目标状态

 Feedforward: the movement is based on the representation in the brain of the intended action the velocity profiles between children and adults

the adaptation paradigm

DYNAMICAL SYSTEMS APPROACH  An example of the dynamical systems approach :  Thelen and her colleagues who conducted a longitudinal study of infants’ reaching (Thelen et al., 1993). They found that different infants have different developmental paths on the way to successful reaching

Behavioral Neuroscience Approach  The behavior changes and brain development are shaping each other across the life span.  The cerebellum is one of the more important structures that has been proposed to be critical in fine motor skill development

 There is no straightforward linkage between brain structure and observed behavior.  Huge variability exists in the human brain suggesting that behavior changes cannot be explained by a single factor.

§7.7SUMMARY  Fine motor skills refer to those movements predominantly produced by the small muscles or muscle groups of the body. These skills usually involve the hands and eyes. The development of skillful fine motor movements is one of the most important developmental achievements in infancy and early childhood owing to their importance in survival (i.e., feeding) and later in tool use and handwriting.

 Fine motor skills typically are performed by the hands, e.g. reaching, grasping, feeding, and writing; although there are non-hand fine motor skills such as, picking up stones with the toes or eye movement.