In understanding and working with the development of fine motor skills, it is important to be aware of several elements that make up the foundation of fine motor skill development; these include bilateral motor control, reaching/grasping, object manipulation, and implement usage.⁷^,¹⁸^,²⁰^,²¹^,²⁸^,³²^,³⁵^,³⁹^,⁴⁰^,⁴² Bilateral motor control includes large and small (proximal and distal) muscle control; reaching/grasping is, in part, an extension of proximal and distal control and is the key component in grasping and in the manipulation of objects. Refined object manipulation that follows is built on the foregoing elements and involves construction and in-hand manipulation activities. Construction activities include stacking blocks, putting simple puzzle pieces together, and putting pegs into a pegboard, among others (Figure 23-1). In-hand manipulation activities involve moving objects within the hand (translation) and include adjusting a toy or object in the hand (shift), rotating an object in the hand (rotation), or picking up multiple objects. Precision grasping and releasing are critical to all of these activities. Finally, tool use, or the use of implements, evolves with and, in part, from earlier experiences with object manipulation skills. Overall, the development of fine motor skills is an ongoing, integrated, and complex process. A schema that depicts the relationships among the various elements involved in fine motor development is shown in Figure 23-2 and discussed in more detail below.

FIGURE 23-1 Construction activities require fine motor skills. (From Parham, L. Diane. *Play in Occupational Therapy for Children*. 2^nd Edition, Mosby, 2007.)

CLINICAL Pearl

A child needs to have the ability to translate, shift, and rotate a pencil in order to write. The pencil is pulled into the palm, translated to the fingers, rotated so the lead is facing toward the paper, and shifted distally so that the fingers are holding the pencil closer to the lead point.

Bilateral motor control: large muscle

Most manipulative activities require both arms and both hands to work together in various ways; this is referred to as bilateral motor control. For example, in cutting, one hand holds and controls the scissors while the other hand is holding and positioning the paper. Therefore, to cut with precision, both hands must move skillfully and in an appropriate relationship to each other.

CLINICAL Pearl

A wheelbarrow race is a great way to develop shoulder stability in older children. Younger children may enjoy “commando” crawling through tunnels and obstacle courses. Children of all ages enjoy sitting on large therapy balls, which can be tilted to facilitate trunk control. Therapists can easily grade the intensity of these activities.

An initial step in the process of fine motor skills development is the development of control of the large, or proximal, muscles of the trunk and arms. Control of the proximal muscles frees the arms and allows them to move independent of the trunk, which ultimately provides the hands and fingers with the support needed for independent, intricate, and delicate movements.

There appears to be a general developmental sequence in acquiring large, or proximal, muscle control. First, control of the muscles of the trunk develops; the arms and legs can then be moved independently. This is followed by the ability to move an arm and a leg on one side of the body independent of the opposite side. This action appears to occur initially on the side of the dominant hand and then on the side of the nondominant one. Finally, control extends to the movement of an arm and a leg on opposite sides of the body, first on the side of the dominant hand and then on the side of the nondominant one. The former movement is known as ipsilateral and the latter as contralateral. Contralateral movements are the forerunner of the arm/foot opposition inherent in most locomotor skills. Control of these large, proximal muscles is typically present by 6 years of age; the major developmental changes occur between 4 and 6 years. The examination of bilateral large muscle control can be accomplished at three different levels: (1) by touching the body parts to be moved (concrete, touch-based level), (2) by pointing to the body parts to be moved (less concrete, more visually based level), and (3) by using verbal labels for the body parts to be observed (abstract, language-based level).

The bilateral motor control involved in fine motor development also progresses from crude two-hand (bimanual) movements to one-hand (unimanual) control to refined use of both hands in lead and assist roles in activities such as buttoning and cutting. Crude bilateral movements represent an initial, possibly inherent, linkage between the hands and typically involve the hands working together as one unit, each performing the same action. The processes involved in unimanual control and refined bimanual control (functional asymmetry) are discussed in greater detail below.

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An infant first transfers objects from one hand to another in two steps. The hands first come into contact with each other; then the object is released from the holding hand to the receiving hand. As unimanual control or dissociation of the hands develop, the infant is able to transfer objects from one hand to another in one step.

Bilateral motor control, small muscle control, and object manipulation

The term small muscle control refers to the control or use of the small muscle masses of the wrist, hands, and fingers to grasp, hold, and manipulate objects. Small muscle, or distal, control typically follows and builds on the development of a minimum of control of the large, more proximal muscles of the trunk, shoulders, and arms. The development of proximal stability of the large muscles supports the mobility of the distal muscles of the wrist, hand, and fingers. Small muscle, distal control allows the child to carry out more precise, adaptive movements that involve intricate manipulation and/or the use of objects and implements. Small muscle control requires adequate hand and finger strength and dexterity; these aspects of hand function are assessed and included in fine motor OT interventions (Figure 23-3).

FIGURE 23-3 Occupational therapist conducts fine motor assessment with input from the occupational therapy assistant (OTA). *DOB*, Date of birth; *DOE*, date of evaluation.

The development of unimanual control is associated with the establishment of hand preference or hand dominance. Bimanual control is also intricately linked to small muscle control and hand preference because both optimal unimanual control and hand dominance are integral to the development of lead and assist hands, or bimanual functional asymmetry. All of the foregoing factors are important in acquiring the capacity to manipulate objects and use implements skillfully. The terms lead and assist hands and bimanual functional asymmetry refer to the use of hands individually in performing different actions involved in a single activity. For example, in the activity of buttoning, one hand manipulates the button, and the other manipulates the fabric where the button is to be placed. Two different actions are performed, one by each hand, to accomplish a single goal or task.

The greatest developmental changes in unimanual distal control appear to take place between 4 and 6 years of age, with lesser improvements between 6 and 8 years. Distal control is often assessed through the performance of such actions as repetitive hand patting, alternating wrist flexion/extension, alternating arm and hand supination/pronation, and repetitive and successive finger tapping. Hand patting requires the child to tap the whole hand against a surface as quickly as possible, while alternating hand flexion/extension requires the child to move the wrist into and out of flexion/extension as rapidly as possible. Alternating supination/pronation involves moving the hands and forearms in alternating rotatory movements (hand palm up to hand palm down repeatedly) as rapidly as possible. Finger movement tasks involve either tapping one finger repeatedly or touching each finger to the thumb in sequence, starting with the index finger; both of these tasks are performed as rapidly as possible. The capacity to perform such movements rapidly and easily is one way to establish the possible presence or absence of deficits in underlying fine motor control processes.

CLINICAL Pearl

Whole-hand and finger puppets can be used to encourage repetitive hand and finger movements to make the intervention session more fun and playful.

Reaching, grasping, releasing, and fine motor development

Reaching, grasping, and releasing are other important components of the development of fine motor skills (both object manipulation and implement or tool usage). For example, to manipulate an object, the child must first obtain it; this requires the child to reach for and grasp the object and then use the fingers to move or manipulate it in appropriate ways. Reaching for an object and grasping it successfully involve locating the hand in space, locating the object in space, and then acting to bring the two together. It is important that the child both see and feel the hand in relation to the object to be grasped. In other words, it is important for the person to see and feel the hand and arm as they move toward and grasp the object. The child must effectively process visual, proprioceptive, and tactile information (seeing and feeling the hand and arm move) and then create and carry out a movement that gets the hand to the object for grasping and manipulation. This process is known as intersensory integration or sensory-motor integration. These processes tend to happen naturally and spontaneously during development. When or if they do not, fine motor development is often difficult.

Overall, infants tend to reach out spontaneously for objects that move across their visual fields; this reaching tendency is present at birth and is initially visually evoked; that is, the response appears to be a spontaneous reaction to seeing an object in the environment. Although this early reaching action is crude, it is directed toward the object and will later become a voluntary act that is more precise and better controlled. At this point in his or her development, the child decides when, where, how, and whether to reach for an object and does so skillfully.

Grasping an object is the second step in its manipulation. The early grasping response is reflexive or instinctive in nature and is based largely on proprioceptive and tactile input; later it evolves into a voluntary grasp that relies more on visual information. Vision allows the young child to examine the object (determine its size, shape, location, and other factors) more precisely and then shape the hand and create the force necessary for holding and manipulating the object. Of course, this process is repeated multiple times in many different ways for objects of different sizes, shapes, weights, and uses. Therefore, vision and visual perception become integral factors in the development of fine motor skills. Releasing an object, or letting it go, is another part of fine motor development and object manipulation. It requires some inhibition of the earlier grasp reflex response because manipulating an object actually involves skillful grasping and releasing of the object in a variety of ways, which allow the child to explore and/or use the object for a particular purpose (in-hand manipulation).

Eye movement control

Visual perception and thus eye movement control (how the child moves the eyes to focus on or follow objects in the environment) play an important role in fine motor control and development. Some evidence has shown that a significant number of children (approximately 78%) with fine motor control problems also exhibit poor saccadic eye movements along with less well-developed pursuit eye movements. In saccadic eye movements, the eyes move rapidly and accurately from item to item (e.g., from point to point in a picture or letter to letter or word to word in reading). In pursuit tracking movements, the eyes move to follow slow-moving objects, among other things. These eye movements allow the eyes and the brain to get the information needed to make appropriate decisions about phenomena such as movement, objects, and the content of the written word. Both types of eye movement can be improved with practice and may be worth considering as part of the enrichment activities for improving fine motor control.

CLINICAL Pearl

Using black-and-white infant toys (created to stimulate infants) may improve the eye muscles of children with eye tracking difficulties. OT practitioners may encourage children to follow the slow-moving (for pursuit tracking movements) or fast-moving (for saccadic movements) object. For older children, black-and-white pictures or computer games in which the child must point to the object on the screen may be more appropriate.

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If a child has eye movement control deficits, the OT practitioner may work closely with an optometrist who specializes in vision therapy. Optometrists who specialize in vision therapy have special lenses and other visual tools that enhance eye movement control interventions.

Development of object manipulation skills

Object manipulation may be thought of as the manual control of objects (i.e., the ability to manipulate or use an object in a variety of desired ways). Object manipulation may involve what some refer to as construction activities and in-hand manipulation activities; both can be bimanual or unimanual. Examples of construction activities include putting puzzles together, building towers out of building blocks, making shapes with Lego, and putting pegs into a pegboard. Examples of in-hand manipulation activities include turning the lid of a jar, picking up multiple objects, and others in which the thumb plays a prominent role (Figure 23-4). The skillful manipulation of objects involves, in particular, the ability to control the actions of individual fingers and groups of fingers (manual dexterity). It also requires that the arm and hand work together to control or use the object (bimanual control); this is often referred to as the arm–hand linkage system and is the basic foundation for the subsequent development of implement usage skills.⁵^,⁶^,^11–15^,¹⁹^,²²^,²⁸^,²⁹^,³⁹^,⁴⁰

FIGURE 23-4 Table top activities such as constructing block structures require fine motor skills, concentration, and the ability to problem solve and sequence. (From Hockenberry, *Marilyn J. Wong’s Essentials of Pediatric Nursing*, 7^th Edition. Mosby, 2005.)

The arm and the hand each play different roles in the successful manipulation of objects, the nature of which changes in relation to the goal of the task and the age and developmental level of the child. For example, in placing pegs into a pegboard (construction activity), the arm provides support for the hands and fingers to hold the pegs and also positions the hand in such a way that the pegs can be put into the board. In eating with a spoon (implement or tool usage), the arm positions the hand to hold the spoon; and the hand and fingers control the position and movement of the spoon.

Generally, the arm and the hand each have three independent functions that are used in different ways to accomplish different tasks. The three functions of the arm are (1) positioning the hand (i.e., getting the hand in an appropriate location or position for grasping the object of interest); (2) supporting the hand (i.e., keeping the arm/hand combination relatively immobile so that the necessary hand and finger movements can be executed properly); and (3) on some occasions, producing force such as that required in pounding a peg or turning a doorknob. The functions of the hand are to pick up the object, hold or grasp the object, and execute the movements needed to manipulate the object or implement. Developmental progressions have been loosely defined for each of these hand functions.

Picking up an object

In picking up an object, the child may initially scoop it up with the whole hand, often on the ulnar (little finger) side. Later, the person uses individual fingers and finger actions to pick up the object. A pincer grasp that involves finger–thumb opposition, for example, is the use of the thumb and the index finger. A pincer grasp is usually effective in picking up very small objects such as a Cheerio or a piece of pinestraw. A three-jaw chuck or pince involves the thumb opposing with the index and middle fingers, which is usually the most effective way to pick up slightly larger object such as a one-inch block.

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A child first develops a pad-to-pad pincer grasp, in which the small object is held between the pads of the thumb and the index finger. As motor control is refined, a tip-to-tip pincer grasp evolves such that the small object is held between the tip of the thumb and the tip of the index finger.

CLINICAL Pearl

Children who have force production deficits often will crush a styrofoam cup because the force of their grasp is too much. A plastic cup is recommended to prevent dropping and spillage.

Activities to promote strength development

Adequate muscular strength of the hands and fingers is important to produce the force needed to carry out fine motor tasks with skill and efficiency.⁴⁰ The following are some examples of activities that may be helpful in strength development:

• Pinch putty between the thumb and individual fingers in sequence from the index to the little finger, and vice versa.

• Push slowly into a putty ball; hold each finger extended.

• Press cookie cutter into Play-Doh or another similar substance.

• Hold putty or soft ball in the palm of the hand and squeeze.

• Squeeze a turkey baster or other plastic item.

• Crumble sheets of paper into a ball.

• Twist or wring putty or other material with palm toward and away from the body.

• Squeeze water out of a sponge or other soft material.

• Hold playing cards between two fingers; try to knock the cards out of the finger grasp

• Holding a weight in one hand, with the palm down and forearm supported, flex and extend the wrist.

• Use rubber bands as resistance to finger and wrist movements.

One way to assess the ability of the child to consistently produce an appropriate amount of force is the use of tapping activities. Can the child tap consistently for a designated period? Variation in tapping can be easily observed, and it becomes readily evident when a metronome is used in the assessment. The metronome can be used to help the child improve the consistency of the timing of force production. Children with coordination difficulties generally exhibit an inability to maintain a consistent tapping rate; this is especially true if the tapping has to be performed for a long period. The performance of these children becomes more variable as the time involved in tapping increases. Their performance is most consistent in the initial 10 seconds of such an activity and becomes much more variable as the duration increases to 20 or 30 seconds. It is a good idea to use short durations initially and gradually increase them as the child improves.

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For older children, computer typing programs that use musical rhythms to teach keyboarding skills are available.

Developmental progression for object manipulation

Several overlapping trends or dimensions of behavior need to be considered in assessing the development of fine motor object manipulation skills.⁶^,¹⁴^,³⁹^,⁴⁰ The manipulation skill indicators include the development of hand control (how and for what purpose the child uses the hands), spatial–temporal accuracy (skills that require judging the space and timing of the action of the hands), and self-help skills. Examples of the general developmental sequence of some of these behaviors are given in Box 23-1.

BOX 23-1 Examples of General Developmental Sequences for Object Manipulation

Hand control